BUILDING SERVICES BRANCH TESTING AND COMMISSIONING PROCEDURE NO. 1 FOR AIR-CONDITIONING, REFRIGERATION, VENTILATION AND CONTROL SYSTEMS IN GOVERNMENT BUILDINGS HONG KONG
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HONG KONG SPECIAL ADMINISTRATIVE REGION GOVERNMENT
Building Services Branch Architectural Services Department (2000 Edition)
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COPYRIGHT 1. This Testing and Commissioning Procedure is solely compiled for use on Airconditioning, Refrigeration, Ventilation and Control Systems in Government Buildings of the Hong Kong Special Administrative Region. 2. This Testing and Commissioning Procedure is copyrighted and all rights (including subsequent amendment) are reserved. 3. It is hereby declared that the procedure contained therein may not be pertinent or fully cover the Air-conditioning, Refrigeration, Ventilation and Control Systems carried out by other Government Departments or private sectors. Prior consent by the Director of Architectural Services must be obtained for adoption of this testing and commissioning procedure for Air-conditioning, Refrigeration, Ventilation and Control Systems of other nature or locations.
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TABLE OF CONTENT Page 1.
Introduction
1
2.
General Requirements
1
3.
Testing and Inspection
2
4.
Statutory Inspection/Commissioning
3
5.
Calibrated Equipment
93
Appendix A
Page
Testing and Commissioning Certificate on Air-conditioning, Refrigeration, Ventilation and Control Systems Part 1 :
Details of Project
1
Part 2 :
Declaration
1
Part 3 :
Items Inspected and Tested
2
Part 4 :
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3.1
The General Requirements as indicated in the T & C procedure have been complied with.
2
3.2
Precommissioning Checks
2
3.3
Setting to Work & Balancing
2
3.4
Comments
6
Test Record attached to the Test Certificate
7
4.1
General
7
4.2
Packaged Water Chillers
7
4.3
Air-Cooled Condensing Sets
8
4.4
Cooling Towers
9
4.5
Pumps (Medium)
10
4.6
Air Handling Units
11
4.7
Heating Coils (Not included in Air Handling Unit)
13
I
TABLE OF CONTENT Page 4.8
Ducts, Grilles, Diffusers etc.
13
4.9
Testing Equipment
14
Appendix B
Page
Testing and Commissioning progress chart for Air-conditioning, Refrigeration, Ventilation and Control Systems
Appendix C
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Page Flow Chart for Testing and Commissioning Procedure on Airconditioning, Refrigeration, Ventilation and Control Systems
1
Figure 1
Example of Water Distribution System
2
Figure 2
Example of Air Distribution System
3
Figure 3
Example of Air Distribution Branch
3
Figure 4
Example of Low Velocity Supply Air System
4
Figure 5
Example of Air Flow Sheet
5
II
B.S.B. Testing and Commissioning Procedure No. 1 Air-conditioning, Refrigeration, Ventilation and Control Systems
1.
Introduction 1.1
This procedure is intended to lay down the minimum testing and commissioning requirements to be carried out by the Contractor on a new Air-conditioning, Refrigeration, Ventilation and Control Systems upon completion or on an existing Air-conditioning, Refrigeration, Ventilation and Control Systems after a major alteration. Additional testing and commissioning (T & C) requirements may be proposed by the Contractor as appropriate and agreed by the Project Building Services Engineer (PBSE), e.g. for special equipment supplied and/or installed by the Contractor.
1.2
This procedure is also written to facilitate the PBSE and Project Building Services Inspector (PBSI) in carrying out the following aspects of work with respect to T & C. (i)
To vet and approve the T & C procedures proposed and submitted by the Contractor.
(ii)
To witness those T & C procedures as specified.
(iii) To receive the T & C certificate and other supporting data. 2.
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General Requirements 2.1
The Contractor shall submit the T&C procedures to the PBSE for approval. The submission shall be made at least one month before the commencement of T&C.
2.2
Where tests are required to be witnessed by the PBSE/PBSI, the Contractor shall give due advance notice (usually not less than three days) and provide details of date, time and type of tests to be performed.
2.3
Upon completion of such T & C procedure, the Contractor shall complete and sign a testing and commissioning certificate as Appendix A, to the effect that agreed T & C procedures have been duly carried out.
2.4
Before carrying out any test, the Contractor shall ensure that the installations comply with the statutory requirements and regulations.
2.5
Part of the testing & commissioning may be required to be carried out in Supplier’s premises in accordance with the provisions in the General/Particular Specification.
2.6
The testing & commissioning of systems under various sections may be 1
required to be carried out in parts or as a whole depending upon the status of the progress of work or as dictated by the requirements of the Contract. 2.7
3.
It must be ensured that the personnel carrying out the tests are trained, experienced commissioning engineers and for specialised items such as refrigeration plants, control equipment etc., these may be carried out by the manufacturers’ own T & C engineers if necessary.
Testing and Inspection 3.1
The requirements are in general as specified in the latest General Specification for Air-conditioning, Refrigeration, Ventilation and Control Systems issued by Building Services Branch of Architectural Services Department, herein after described as General Specification. If there is any discrepancy between this procedure and the General Specification, the General Specification shall take precedence.
3.2
The Contractor shall carry out the tests and inspections as shown in Part 3 and record the test results on Part 4 of Appendix A and as agreed between the Project BSE and the Contractor.
3.3
The Contractor shall provide all the necessary staff, labour, materials and equipment for a thorough test and examination of the installation.
3.4
The purpose of this T & C procedure is to provide the Contractor a guideline which would ensure that the building environmental systems produce the design objectives. It includes : (i)
The balance of air and water distribution.
(ii)
The adjustment of total system to provide design quantities.
(iii) The electrical measurement. (iv) The verification of performance of all equipment and automatic controls. (v) 3.5
The sound and vibration measurement.
The objectives as outlined above can be accomplished by : (i)
Checking installations for conformity to design.
(ii)
Measurement and establishment of fluid quantities of the system as required to meet design specification.
(iii) Recording and reporting the results. 3.6
The procedure covers the following sections of testing & commissioning : (i)
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Preliminary checks 2
(ii)
Setting to work and balancing the systems
(iii) Recording of test data 4.
Statutory Inspection/Commissioning 4.1
After the proper testing and commissioning of the Air-conditioning, Refrigeration, Ventilation and Control Systems, the Contractor shall notify the appropriate Authority, through the PBSE, on the completion of the installation and its readiness for inspection and testing.
4.2
Before operating the system to carry out T & C, the following steps should be followed : (i)
Obtain design drawings and specifications and to be thoroughly acquainted with the design intent.
(ii)
Obtain copies of approved shop drawings of all air handling equipment, outlets (supply, return and exhaust) and temperature control diagrams.
(iii) Compare design to installed equipment and field installation. (iv) Check the system from the air handling equipment to terminal units to determine variations of installation from design. (v)
Check filters and dampers (for both volume control and fire protection) for correct and locked position, and temperature control for completeness of installation before starting fans.
(vi) Obtain manufacturer’s outlet factors and recommended procedure of testing. Summation of required outlet volumes permits a crosscheck with required fan volumes. (vii) Obtain schematic diagrams of system as-built ductwork and piping layouts to facilitate reporting. 4.3
During construction certain tests will have been carried out on the installations to ensure their suitability for operating at the design conditions. Such test certificates have to be issued together with certificates of any works tests. 4.3.1 Works Tests
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a)
Works tests shall be carried out in accordance with the type normally associated with the specified item of equipment and to the standards as laid down in the Specification and the Conditions of Contract.
b)
Works static pressure tests will be carried out on such items of plant and equipment as pressure vessels, water coils, heat exchangers and plate exchangers, radiators and convector 3
elements, and all items of plant or equipment handling refrigerant, as laid down in the Specification and the Conditions of Contract. c)
Dynamic rotation tests will be carried out on such items as fan impellers and drives, compressor, pump impellers and drives. Tests shall be conducted through the entire rotational speed range up to a maximum of 150% design operating speed if the provision have been made in the Conditions of Contract. When items of plant are purchased ex-stock, manufacturer’s test certificate will suffice.
d)
Rotational test on electric motors will not be carried out if the equipment is constructed to the requisite current British Standard or any other approved standards.
4.3.2 Welds in Piped Services a)
The welds shall be inspected by means of cutting. The total number of welds to be inspected should be limited to 2.5% of the total. If any of the welds are found to be of sub-standard, equal number of further welds shall be cut out.
b)
At least two welds per operative shall be inspected. Each welder employed on the works shall be allocated an identification number and each site weld shall be stamped with the appropriate identification number to identify the operative.
c)
Where required by the Particular Specification, some welds on large bore or high pressure mains may be subject to testing by radiographic or ultrasonic methods. Such non-destructive testing should be carried out by specialized laboratories who both perform the tests and analyse the results.
4.3.3 Pressure Testing of Piped Services
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a)
Pressure testing of piped services systems, or any section of a completed system, shall be completed prior to the application of any thermal insulation to the cleaned pipe surfaces.
b)
Ensure that all plugs, caps, tees and drain fittings required to enable the tests to be carried out have been provided.
c)
Before hydraulic tests are carried out, all safety valves, gauges etc. shall be effectively isolated or removed. For all nondestructive safety equipment, these shall be effectively tested at their design working pressure during commissioning of the installation.
d)
Tests on lengths of pipe or portions of systems shall be applied by filling the section to be tested with water and raising its pressure to the figure quoted in the Specification. 4
e)
The section shall then be left fully isolated without further strokes of the pump and all joints must remain watertight for a period of at least two hours. As to whether or not the section is sound shall be governed by the rate at which the pressure falls.
f)
Any fault discovered during such tests shall be at once remedied and the test reapplied until the section under test is considered sound. Remedial work shall conform with all the requirements of the General and Particular Specification for materials and standards of workmanship.
g)
Upon completion of the test, the water shall be released and drained away as rapidly as possible, the section being then thoroughly sluiced through to ensure the removal of as much dirt and dross as possible before being refilled and put into service.
4.3.4 Air Leakage Test for Ductwork a)
Where required by the Specification, all air-conditioning supply ductwork connected to central air handling units shall be tested for air leakage in accordance with - HVCA (V12) Specification for Sheet Metal Ductwork (DW series).
b)
For preliminary and visual test, the method will include using chemical ‘white’ smoke generators. All openings in the ductwork shall be properly sealed followed by the introduction of smoke.
4.4
The flow-chart in Appendix C provides the sequence, responsibilities and guidelines for the testing and commissioning procedure.
4.5
Precommissioning Checks 4.5.1 Water Distribution System 4.5.1.1
System Cleanliness
Irrespective of the precautions taken during the construction stage to keep the internal surfaces of pipework clean, it should be assumed that it has not been done so and one of the following procedures shall be used to clean the system. 4.5.1.1.1
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Flushing
a)
Divide the pipework system into self-draining sections so that the maximum possible flushing rate is achieved.
b)
Isolate items which are particularly sensitive to dirt, such as pumps, small bore coils and tubes, including induction and other room unit coils and spray nozzles. Washers, cooling 5
tower basins, feed and other tanks which may have accumulated with deposits during manufacturing or installation should also be isolated and flushed independently. c)
Where make-up or feed tanks are used for flushing, ensure that the maximum possible pressure is sustained on the system during the flushing process. This may necessitate the provision of a temporary parallel feed of mains water into the tank where the ball valve has limited capacity. This procedure assumes that the connection of the section from the tank is at a high point in the section being flushed.
d)
Ensure : (i)
that flushing is carried out from the upper to the lower sections of a multi-section system, finishing with the lowest point; initial flushing should always be from small bore to large bore pipe. Particular care is required on reverse return systems and systems with roof-top chiller or boiler plant;
(ii)
that the large bore outlet is not opened until the section being flushed is fully primed;
(iii) that the maximum possible flow rates are used; (iv) that flushing continues until the outflow runs clear. 4.5.1.1.2. Cleaning by Forced Circulation Where facilities exist, final cleaning of systems can be achieved by circulation of the medium in order to collect dirt at filters or other selected points in the system. Where circulation is achieved by the use of a pump, this action shall be deferred until the pump has been set to work in accordance with para. 4.6.1.4. 4.5.1.1.3
Chemical Cleaning & Corrosion Inhibiting
Chemical cleaning, if required, shall be carried out as specified by the specialist. Corrosion inhibiting, where specified, should be carried out after flushing. 4.5.1.2
State of System
Check :
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(i)
that where special valve packing is required, e.g. grease in medium or high temperature system, this shall be in accordance with manufacturer’s instructions;
(ii)
that pressure tests have been completed throughout; 6
(iii) that the system has been cleaned in accordance with para. 4.5.1.1; (iv) that permanent water connections have been made; (v) 4.5.1.3
that water treatment is available if specified. Check of System before Filling
Check : (i)
that probes, pockets, pressure gauges, siphons, orifice plates and taps, and air vents are installed;
(ii)
that drains and overflows are connected and free from blockage;
(iii) that connections to heating and cooling coils and all other heat exchangers are correct in relation to the design water flow direction; (iv) that control and non-return valves are installed the right way round; (v)
that relief valves are installed as specified and are free to operate;
(vi) that relief valve outlets are piped away to suitable drain points; (vii) the expansion devices for alignment and freedom from obstruction; (viii) the presence of special pump priming devices where specified; (ix) that the strainer mesh is of the correct grade and material; (x)
that the changeover devices for duplex strainers are operative and that there are means of isolation for single strainers;
(xi) that washers, tanks, nozzles and filters are clean; (xii) that tank covers are provided where specified; (xiii) that drain cocks are closed and other valves are left open or closed according to the plan for filling (see para. 4.5.1.5 below); (xiv) that the feed connection is in its correct location; BSBTC-01
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(xv) that all pipework and fittings are adequately supported, guided and/or anchored where applicable. 4.5.1.4
Mechanical Checks
4.5.1.4.1. Pumps Check : (i)
the external cleanliness of the pumps;
(ii)
that the flow direction is correct;
(iii) that all components, bolts, fixings, etc., are secured; (iv) that the impeller is free to rotate; (v)
the level and plumb of pump and motor shaft and slide rails; direct drive pumps require particular attention in this respect;
(vi) the anti-vibration mountings for correct deflection; (vii) that the correct drive is fitted; (viii) that the pipework imposes no strain at the pump connections; (ix) the securing and alignment of pulleys and couplings; (x)
the belt tension and match;
(xi) the cleanliness of the bearing; (xii) that the lubricant is fresh and of the correct grade; (xiii) that the coolant is available at the bearings when specified; (xiv) that glands are correctly packed and the gland nuts are finger-tight only, pending adjustment to correct drip rate after start-up; (xv) that drive guards are fitted and the access for speed measurement is provided. 4.5.1.4.2. Motorized Valves and Float Switches Check : (i) BSBTC-01
that the valves are installed the correct way round; 8
(ii)
that the valve spindles are free to move;
(iii) for freedom from excessive looseness; (iv) the fit of pins; (v)
the rigidity of the mountings;
(vi) the stiffness of the linkage members; (vii) the tightness of locking devices; (viii) the bearing lubrication. 4.5.1.5
System Filling
Charge the system with water (treated, if so specified) to a prepared plan, the object of the plan being successful venting by filling from the bottom upwards forcing the air to high points - for venting to atmosphere. Careful consideration should be given to the stage of valves and air vents before and during filling to avoid air-locks and excessive spillage. Take care not to exceed the working pressure of the system when filling from a high pressure source. When the whole system is filled, disconnect the filling source, open the permanent supply and adjust the tank levels. 4.5.1.6.
Electrical Checks
Prior to the initial running of any electrically driven pump, valve or electric water heater, the following procedures should be adopted. 4.5.1.6.1. With all Electrical Supplies Isolated Check : (i)
the local isolation of motor and control circuits;
(ii)
that there are no unshrouded live components within the panels;
(iii) that the panels and switchgears are clean; (iv) that the motor and surrounding areas are clean and dry; (v)
that the transit packing has been removed from contactors and other equipment;
(vi) that there is no mechanical damage to switchgears and that thermostats are of a suitable range to operate at BSBTC-01
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ambient temperature (see para. 4.6.1.2); (vii) that all mechanical checks on the pump and motor or valve are completed (see para. 4.5.1.4); (viii) that all connections are tight on busbars and wirings; (ix) that the internal links on the starter are correct; (x)
that all power and control wirings have been completed in detail to the circuit diagram (paying special attention to circuits for star-delta connected or specially wound motors);
(xi) that the fuse ratings are correct; (xii) that the starter overloads are set correctly in relation to the motor name-plate full load current; (xiii) that the dashpots are charged with the correct fluid and the time adjustments and levels are identical; (xiv) that insulation tests on the motor have been performed satisfactorily; (xv) that the adjustable thermal cut-outs are set correctly (check manufacturers’ test certificates); (xvi) that all cover plates are fitted. 4.5.1.6.2
With the Electrical Supply Available
(i)
Check that the declared voltage is available on all supply phases.
(ii)
Where motor powers are substantial or reduced voltage starting or complex interlocks are involved, the control circuit logic and the starter operation should be tested before the motor is rotated. The supply should first be isolated by the withdrawal of the two power fuses not associated with the control circuit or the disconnection of cables. The “red” phase shall be used for control circuit normally. The control circuit fuse must be checked to ensure that it is rated to give the correct discriminatory protection to the control circuit cables. The control circuit should be activated and the starter operation observed. Adjust the timers. Check for positive operation of all contactors, relays and interlocks. Finally, open the isolators, reinstate the power connections and close the isolators.
(iii) Where small motors have direct-on-line starting and BSBTC-01
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simple control circuits, the starter operation, etc., should be checked when first starting the motor. (iv) Never energize electric valve motors until the checks (para. 4.5.1.4.2), have been completed. 4.5.2 Air Distribution System 4.5.2.1
System Cleanliness
Prior to the fitting of filters and washer elements, ensure that the environment is clean and then proceed to check the following for cleanliness : (i)
air intake screens;
(ii)
fan and other equipment chambers;
(iii) floor gulley and all drainage traps; (iv) fan internals; (v)
heater and cooler batteries;
(vi) cooling coil trays; (vii) washer tanks; (viii) humidifiers; (ix) eliminators; (x)
dampers;
(xi) ducting and other airways; (xii) sensing elements; (xiii) terminal units; 4.5.2.2
Air Regulating Devices and Other Components Within Airways
Checks :
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(i)
that turning vanes, thermal insulation, acoustic linings, battery fins and sensing elements have been fitted and are undamaged;
(ii)
that heater and cooler batteries, humidifiers, filters, silencers, fire dampers, sail switches, volume control dampers etc., are installed correctly in relation to air 11
flow; (iii) the damper free-movement, clearances seating pining to damper spindles, position of blades with respect to quadrant indication, relative positions of blades in multileaf dampers; (iv) the control linkages on motorized dampers for alignment, rigidity, lubrication and free movement without slackness; (v)
that dampers throughout the system are secured in open position with damper actuators disconnected;
(vi) the free movement of fire dampers together with the location of, access to and fitting of, fusible link assembly; all fire dampers are finally secured in open position; (vii) that all adjustable louvres are set without deflection, i.e. normal to face of grille. Adjustable cones on diffusers are set either all in the fully up or all in the fully down position; (viii) that test holes are provided for measurement of total air flow. 4.5.2.3
Visual Checks for Air tightness
It is assumed that pressure testing of high velocity system ductwork is carried out during construction. This is essential on all high velocity systems and is widely required for low velocity systems. Check : (i)
the builder’s work ducts and shafts seals;
(ii)
that access doors to plant equipment are sealed around the whole periphery;
(iii) the ductwork joints, including flexible couplings; (iv) that inspection covers are fitted; (v)
that drain water seals are fitted;
(vi) that plugs or covers for test holes are fitted. 4.5.2.4
Mechanical Checks
4.5.2.4.1. Fans BSBTC-01
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Check : (i)
the external cleanliness of fans;
(ii)
that all components, bolts, fixing, etc., are secured;
(iii) that the impeller is secured, free to rotate, of correct handing and correct clearances; (iv) that axial-flow-type fans are installed for correct air flow direction and, where compounded, in correct order; (v)
the level and plumb of fan and motor shaft and slide rails;
(vi) the anti-vibration mountings for correct deflection; (vii) the static balance; (viii) that the correct drive is fitted; (ix) the securing and alignment of pulleys and couplings; (x)
the belt tension and match;
(xi) the cleanliness of the bearing; (xii) that the lubricant is fresh and of the correct grade; (xiii) that the coolant is available at bearings when specified; (xiv) that drive guards are fitted and the access for speed measurement is provided; (xv) for satisfactory operation of inlet guide vanes over full range of movement; (xvi) that fan casings to be earthed are correctly and soundly bonded. 4.5.2.4.2
Automatic Fabric Filters
Check : (i)
the level mounting;
(ii)
the alignment, clearances and free movement of spools, drives and limit switches;
(iii) the lubrication of spool drive motor, gearbox and spool bearings. 4.5.2.5 BSBTC-01
Electrical Checks 13
Prior to the initial running of any electrical driven fan, electric air heater or automatically advancing filter, the following procedures shall be adopted : 4.5.2.5.1. With all Electrical Supplies Isolated Check : (i)
the local isolation of motor and control circuits;
(ii)
that there are no unshrouded live components within the panels;
(iii) that panels and switchgears are clean; (iv) that the motor and surrounding areas are clean; air heaters are clean; (v)
that the transit packing has been removed from contactors and other equipment;
(vi) that there is no mechanical damage to switchgears or air heaters; (vii) that all mechanical checks on fan, motor and automatic filter are completed (see para. 4.5.2.4); (viii) that all connections are tight on busbars and wirings; (ix) that the internal links on the starter are correct; (x)
that all power and control wirings have been completed in detail to the circuit diagram. (paying special attention to circuits for star-delta connected, or specially wounded motors);
(xi) that fuse ratings are correct; (xii) that starter overloads are set correctly in relation to motor name-plate full load current. (xiii) that the dashpots are charged with the correct fluid and the time adjustments and levels are identical; (xiv) that insulation tests on motor have been performed satisfactorily; (xv) that the adjustable thermal cut-outs are set correctly; (xvi) that all cover plates are fitted. BSBTC-01
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4.5.2.5.2. With Electrical Supply Available a)
Check that the declared voltage is available on all supply phases;
b)
Where motor powers are substantial or reduced voltage starting or complex interlocks are involved, the control circuit logic and the starter operation should be tested before the motor is rotated. The supply should first be isolated; then by the withdrawal of two power fuses or the disconnection of cables followed by the reinstatement of supply to the control circuit alone, the control circuit shall be activated and starter operation observed. Adjust the timers. Check for proper operation of all contactors, relays and interlocks. Finally open the isolators, reinstate power connections and close the isolators;
c)
Where small motors have direct-on-line starting and simple control circuits, the starter operation, etc., should be checked when first starting motor.
4.5.2.6
Electrostatic Precipitators
4.5.2.6.1
Before Approaching the Precipitator :
Establish : (i)
what isolators must be opened and fuses withdrawn to completely disconnect the precipitator plant from the low voltage supply. Beware of interlocking circuits which are energized from elsewhere and where cannot be isolated local to the precipitator;
(ii)
the arrangements for preventing access to any high voltage component until it is at zero potential;
(iii) adequatelabels for instructions / precautions / warnings to be deployed at the entrance access to the precipitator. 4.5.2.6.2
Low Voltage Electrical System
With all low voltage supplies isolated, check : (i)
the local isolation of all low voltage circuits;
(ii)
that switchgears are clean and undamaged;
(iii) that the transit packing has been removed from contactors and other equipment; (iv) that all wiring connections are tight; BSBTC-01
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(v)
that all wirings have been completed in detail to circuit diagram;
(vi) that all cover plates are fitted. 4.5.2.6.3. High Voltage Electrical System Only a skilled and experienced person should be allowed to enter the precipitator casing; he should have with him the interlock key which controls the opening of the access door to the section of precipitator which he is entering or a fuse link or other item to prevent the precipitator being energized; a second person should be stationed outside the door as an observer and he will normally also be in control of the operation of the power pack from this position. Before working on any precipitator system, any residual High Tension (H.T.) charge must be removed using an earthing tool with insulated handle. Where the power pack is remote from the precipitator, a shorting bar should be securely fixed between earth and each H.T. feed to the precipitator. The inbuilt features which prevent access to high voltage components until at zero potential shall, without fail, be checked as follows : (i)
no access to precipitator section via inlet or outlet ductwork connections. Where equipment is being used as a barrier, beware of items which are demountable without tools such as pre-filter cells. Such items should always be supplemented by safety screens as should dampers with blade width exceeding 100 mm;
(ii)
any mechanical interlock correctly links H.T. circuits to earth before access door can be opened and simultaneously de-energizes the H.T. primary circuit to prevent overload caused by the earth link;
(iii) no duplicate keys on site for the mechanical interlock system; (iv) any safety switches fitted to access doors break the Low Tension (L.T.) interlock circuit and destroy H.T. potential before the door is open wide enough to allow an arm or leg to reach a H.T. component within the precipitator casing; also check that switches are held positively open to prevent manual closure or closure by spring failure whilst access door is open; (v)
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check that H.T. potentials are reduced to a safe level within the time it takes to open the door and reaches any H.T. component. This will be of particular importance when door safety switches do not merely augment a 16
mechanical interlock earthing system but are also the sole safety interlock, the value of bleed resistors connected across each capacitor holding H.T. charge will be critical; (vi) a solid copper or aluminium bond connects the H.T. power pack and filter frame to the building main earthing system. 4.5.2.6.4
Cleanliness and Mechanical Condition
With all electrical supplies isolated, H.T. circuits earthed and precautions for staff adopted in accordance with para. 4.5.2.6.3. Check : (i)
for unsafe ladders, walkways or dangerous projections;
(ii)
the internal cleanliness of casing, components, including insulators and ductwork connections;
(iii) that all components are in place and correctly connected. No damage or distortion to ionizer and collector sections. No obvious foreign items in the precipitator cells. Ionizer wires of the correct diameter and type to be provided and to be correctly tensioned. Displacement of these wires from the centres between neutral electrodes should not exceed 5% of the distance between the neutral electrodes. No distortion of collector plates and gaps between plates shall not vary by more than 10%; (iv) that the wash water and fluid coating systems are completed, reservoir is charged with correct fluid and drainage systems are completed and free from blockage. Connection is provided for manual wash; (v)
4.5.2.6.5
that fabric filter sections are loaded with media; if automatic advancing then checks listed in para. 4.5.2.4.2 shall be carried out. Interlock Sequence and Alarm Systems
With electrical supply available check :
4.6
(i)
that the precipitator interlock sequence is correct;
(ii)
that all safety and failure alarm systems are functioned correctly.
Setting to Work & Balancing 4.6.1 Water Distribution System
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4.6.1.1
General
a)
It is not possible in a document of this nature to embody every type of plant layout that the commissioning engineer is likely to encounter in the field. The system as detailed in Fig. 1 at the Appendix C includes only those plant items necessary for clarification of the regulation method described. The procedure given here may have to be adapted to suit the particular arrangement.
b)
The method of manual regulation detailed below is applicable to the following systems :
(i)
Constant volume, variable temperature primary circuits.
(ii)
Constant circuits.
volume,
variable
temperature
secondary
(iii) The maximum flow situation in a variable volume system designed without diversity. 4.6.1.2
Procedures
This section defines the procedures to be carried out in order to achieve a water distribution system which is working satisfactorily and regulated appropriately. These works should normally be carried out with the medium at ambient temperature and therefore there is no need for heated or chilled water to be available. It is unwise, in any event, to allow the commissioning of heating or refrigeration plant (particular if of low thermal capacity) unless design primary circulation flow rates have been established and any likelihood of primary flow rate variations due to modulation of unbalanced secondary systems have been eliminated. 4.6.1.3 a)
BSBTC-01
Checks Prior to Pump Start-Up Check that all normally open isolating and regulating valves are fully open and that all normally close valves are closed. In the case of thermostatic valves it is essential that provision for fully opening of the valves is available. Most electric motorised valves have either provision for manual override of normal control using a switch on the main control box or a facility to position the valves seat mechanically. Pneumatically operated 3way valves rarely have this facility. It is, therefore, necessary to ensure that the control pneumatics are commissioned to the extent that the controller set point can be adjusted to its extremes, to position the valve fully open or fully closed. Space temperature at the sensing point of the controller in the dynamic mode must be considered at this point, i.e. reducing the control set point 18
of a chilled water valve controller which is already sensing a low temperature, will not have the desired effect; provision of a local form of valve heat pressurisation must then be considered, such as a portable air compressor. b)
Open all control valves to full flow to heat exchangers of branch circuits.
c)
Fully open the return and close the flow valve on the pump, close valves on standby pump. Closing the flow valve on the duty pump will limit the initial starting current, which is usually excessive at the first time a pump is running due to bearing stiffness.
4.6.1.4
Initial Running of Electrically Driven Centrifugal Pump Set
4.6.1.4.1
Initial Start
On activating the motor starter, Check : (i)
that the direction and speed of rotation of the motor shaft are correct;
(ii)
that the motor, pump and drive are free from vibration and undue noise;
(iii) the motor adjustment;
starting
current
for
sequence
timing
(iv) the motor running current on all phases to ensure that they are balanced between phases. The flow valve can be opened at this point to raise the running current to say 50 per cent of the name-plate full load current; (v)
that there is no sparking at the commutator or slip rings;
(vi) that there is no overheating of the motor (see BS 587 and BS 5000, Part II); (vii) that there is no seepage of lubricant from the housing; (viii) that the water flow to water-cooled bearings is sufficient; (ix) the reduced speed and motor running current on multispeed motors. 4.6.1.4.2 BSBTC-01
Initial Run 19
a)
A light load should be sustained until the commissioning engineer is satisfied from the checks listed in para. 4.6.1.4.1 and from motor insulation test readings that further load may be applied. Repetitive starting of the motor should be avoided to prevent over-stressing of the fuses, switchgear and motor.
b)
Gradually open the discharge valve until the motor current reaches either the design value or the motor full load current, whichever is the lower.
c)
Check the pump pressure developed by means of the pump altitude gauges against the design pressure. If excessive pressure is developed at this stage, the cause should be investigated.
d)
Adjust the discharge valve so that the flow as determined roughly from the pump characteristic is between 100 and 110 per cent of the design value. Note that the motor full load current is not exceeded.
4.6.1.4.3
Running-in Period
a)
The pump should be run in accordance with the manufacturer’s recommendations and should be under fairly continuous observation. It should not be left running outside normal working hours unless attended. During this time check that the bearings and motor temperature remain steady, that no noise or vibration develops and that no bolts or fixing works loose. Observations may then become less frequent, but it is advisable while later commissioning other parts of the system, to check the pump from time to time. During the first part of the running-in period :
(i)
Vent all high points from time to time. When possible the medium should be heated to maximum permissible levels to assist in removing air from the heating system.
(ii)
Adjust the gland nuts of the pump glands to give the correct drip rate. (Not applicable to mechanical seals.)
b)
After eight hours of running, check all strainers. If these are clean, regulation can commence. If they are dirty, clean the strainers, and run again for at least eight hours and then re-check.
4.6.1.4.4
Standby Pump
On installations with a standby pump, this standby pump should also be commissioned. This pump can be checked against the other and in the unlikely event of failure of the first BSBTC-01
20
pump, commissioning can continue using the second pump. However, a full diagnosis of the reasons for the failure of the duty pump must be made before energizing the standby pump to ensure that any contributory causes are remedied. 4.6.1.4.5
Secondary Pump
In systems with primary and secondary pumps, starting procedures for the primary pumps should be dealt with first. Isolate the secondary system during this period to prevent any accumulated deposits not removed during the flushing process being carried over into the secondary services. After the final check of strainers referred to in para. 4.6.1.4.3.b, the secondary system can be opened up and the starting procedure for the secondary pumps initiated. Only after a final check of both primary and secondary strainers should actual regulation commence.
BSBTC-01
4.6.1.5
Regulation of Water Flow
4.6.1.5.1
The procedures described in this section are a guide to the principles of regulation by proportional balance. Regulation is achieved by measuring the pressure drop across a device with a constant flow coefficient capacity index. Balance is obtained by varying the water flow across the device so that the ratio of actual water flow rate to the design water flow rate (as calculated from the square law relationship of water flow rate to pressure drop) is the same (or within designer’s tolerance) across devices. The device may be a venturi-meter, an orificeplate, a control valve with a known calibrated flow characteristic, a calibrated regulation valve or any device with a constant flow coefficient and a calibrated characteristic reliable as to accuracy and repeatability. Where valves are used they are used in the fully open position, i.e. as a form of fixed orifice. For greater accuracy of absolute flow measurement, only devices covered by British Standard BS 1042 (Measurement of fluid flow in pipes) should be used.
4.6.1.5.2
For the purposes of illustration of the procedures, the system as shown in Fig. 1 of Appendix C will be used. Although the procedures are equally applicable to heating and condensing water circuitry, a chilled water system will be used to illustrate the method. In the heat exchange processes in chilled water systems, temperature differences between the two fluids are generally very small by comparison with heating systems and for this reason the performance of terminal plant is considerably more sensitive to any deviations from the design water flow rate. Hence, the T & C procedure requires more exacting tolerances when balancing this type of system. 21
A series of branch circuits each with several loads have been indicated, flow to each load being controlled by a three-way control valve. Three-way valves in both mixing and diverting applications plus a ‘wild’ noncontrolled coil have been included in the diagram to demonstrate the flexibility of the regulation procedures. In the system illustrated at Fig. 1 of Appendix C, the flow line to each terminal unit is fitted with a regulating/isolating valve which has in-built pressure tappings. This valve is used in its fully open position as a fixed orifice device for water flow rate measurement. The flow measurement may be made anywhere in the branch circuit. A fixed orifice is sometimes incorporated into the regulating valve in the return line. The principle of the balancing method remains the same. The return line from each terminal unit is fitted with a double regulating/isolating valve which is regulated and locked in position during the balancing procedure. Where thereway valve is fitted, a double regulating/isolating valve is installed in the bypass, e.g. across the heat exchanger to balance the bypass with the coil. 4.6.1.5.3 a)
Initial Check of System Water Flow Rates Check the pressure drop across the associated flow regulating valve of each terminal unit by connecting a manometer between points a and b. (Refer to terminal unit “A1” in Fig. 1 of Appendix C) It should be remembered that the reading obtained is related to the design water flow rate by a square law, not a linear relationship. This can be represented by the following expression : P1 P2
=
Q12 Q22
. .. .. .. .
W.1
Where : P1
= Actual pressure drop .. .. kPa
P2
= Design pressure drop .. .. kPa
Q1
= Actual water flow rate.. .. m3/s
Q2
= Design water flow rate.. .. m3/s
Hence the actual percentage of design water flow rate obtained can be deduced from the following calculation : Actual percentage of design water flow rate obtained
BSBTC-01
22
=
√P1 √P2
x
100.. .. .. .. ..W.2
b)
Inspection of the percentages of obtained water flow rate to design water flow rate will indicate which is the least favoured (index) branch and which is the most favoured branch.
c)
At this stage manually set the three-way valve to the bypass position and regulate the bypass valve S so that the pressure drop between a and b equals the reading previously obtained with the three-way valve in the full flow position. Lock the bypass double regulating valve. This procedure is not part of the balancing of the main water distribution system but is the local commissioning of the water flow control of the three-way valve.
4.6.1.5.4
Balancing of Terminals
Start to balance the most favoured branch. The water flow rate of each terminal unit should be balanced to the water flow rate of the index terminal unit in that branch. Each branch is dealt with independently. (The main branch valves A, A’, B, B’, C, C’ in Fig. 1 of Appendix C are all fully open at this stage). Assume branch A-A’ has the highest unit A1 (remote in hydraulic terms relative to the circulating pump) is the least favoured. If it is not, connect one manometer across valve No. 1 and a second manometer across the regulating valve associated with the least favoured terminal unit. Regulate the down-steam double regulating valve No. 2 until the percentage of design water flow rate across the two valves are equal (or within the designer’s tolerances). Leaving the first manometer connected across valve No. 1 (a and b) while the rest of the branch A-A’ is balanced. Connect the second manometer across valve No. 3. Regulate valve No. 4 until the percentage of design water flow rate is the same (or within the designer’s tolerances) as valve No. 1. Repeat this procedure for all valves on branch A-A’. Remove both manometers and start on the next most favoured branch. Carry on until the water flow rates of all terminal units on all branches are balanced within each branch. 4.6.1.5.5
Balancing of Complete Branches
For this stage, the branch regulation valves (A’, B’ and C’) will be the measuring stations. Check the percentage of design water flow rate across each branch regulating valve. It will then be apparent that which is the index branch (say A-A’). Set the first manometer across valve No. A’ and the second manometer across valve B’ until the percentage of design water flow rates across the valves A’ and B’ are equal (or within the designer’s tolerances for branch balance). Leaving the first BSBTC-01
23
manometer connected across valve A’, repeat this procedure for all branches (in this example for branch C-C’) working back from the most remote branch to the branch nearest the pump. (Where, at the start of branch balancing, if the most remote branch is not the index or least favoured branch, it should be made so, in the manner described for terminal balance.) 4.6.1.5.6
Secondary Mixing Set Regulating
For the purpose of illustration it is assumed that the design water flow rate as delivered by the secondary circulating pump is in excess of the design water flow rate of the secondary mixing three-way valve. The first manometer is connected across valve No. 11 and the second manometer across valve No. 14. With valve No. 13 fully open and the secondary threeway valve in the full flow position, the percentage of design water flow rate through valve No. 11 should be in excess of the percentage through valve No. 14. (Regulate valve No. 13 until the percentage of design water flow rate are equal (or within the designer’s tolerances). Manually set the secondary threeway valve to the bypass position and regulate valve No. 12 until the percentage of water flow rate through valve No. 11 equals the percentage obtained with the three-way valve in the full flow position. 4.6.1.5.7
Secondary and Primary Final Regulation
Total water flow is measured by connecting a manometer (or other accurate measuring device) across the total flow measuring device such as an orifice plate or venturi meter. The secondary total water flow rate is regulated first by adjustment of valve No. 15 until the pressure drop across the total flow device equals the design pressure drop. This procedure is repeated finally on the primary circuit with the manometer connected across the primary total flow measuring device and adjusting the double regulating valve No. 16. At this stage rescan all the measuring stations for record purposes including the pump differential pressures and the evaporator pressure drop and, where possible, check against the manufacturer’s data. 4.6.1.5.8. Other Regulating Valves Valves incorporating an integral orifice plate, double regulating facility and metering station as a single unit, or double regulating valve plus separate orifice plate and metering station are also available, this eliminate the need for a regulating valve with in-built pressure tappings. The T & C procedures would be similar but check with the manufacturer. 4.6.2 Air Distribution System BSBTC-01
24
4.6.2.1
Precautions Against Airborne Dirt
The system should have been cleaned internally in accordance with para. 4.5.2.1 but further precautions shall be taken before starting the fans for the first time : (i)
disconnect final flexible connections to terminal units such as induction units and blender boxes which are susceptible to faulty operation through dirtiness;
(ii)
preferably remove all high efficiency terminal filters which are susceptible to rapid choking;
(iii) check that suitable temporary protection has been provided for anything within spaces served by the system which could be damaged by initial discharge of dust from supply outlets at first start-up; (iv) install main inlet filter cells, properly coated as necessary, to avoid introducing additional dirt into the ductwork system after start-up. Check seating of cells for airtightness. Commission automatic fabric and electrostatic filters in accordance with para. 4.6.2.2 and 4.6.2.3; 4.6.2.2
BSBTC-01
Automatic Fabric Filters
a)
Preliminary checks in accordance with para. 4.5.2.4.b and 4.5.2.5 shall have been completed.
b)
Install filter media in accordance with manufacturer’s instructions.
c)
Energize the filter without air flow. With the differential pressure control device looped out, close the isolator controlling supply to filter and test operation by the manual advance switch. Leave the filter on manual advance until the correct total air flow is established through the filter.
d)
The correct total air flow through the filter shall be established as part of the procedure for regulation of air flow (see para. 4.6.2.5 below).
e)
Commission the differential pressure controller after establishment of correct air flow as described in para. 4.6.2.5.7 for which the clean filter condition will normally have been manually selected. An inclined manometer with pressure sampling points adjacent to the filter fabric will be used to measure the prevailing static pressure drop across the clean filter and this will be recorded. The filter may then be progressively blanked 25
off (e.g. with cardboard) until the manometer indicates the design ‘dirty filter’ pressure drop. The differential pressure control will be adjusted to start advancing the filter at this ‘dirty filter’ pressure drop and to stop advancing the filter at the design clean filter pressure drop. 4.6.2.3
Electrostatic Precipitators
Only a skilled and experienced person should be allowed to enter the precipitator casing; he should have with him the mechanical interlock key which controls the opening of the access door to the section of precipitator which he is entering or a fuse link or other item to prevent the precipitator being energized; a second person should be stationed outside the door as an observer and he will normally also be in control of the operation of the power pack from this position. Before working on any precipitator system, any residual H.T. charge must be removed using an earthing tool with insulated handle. Where the power pack is remote from the precipitator a shorting bar should be securely fixed between earth and each H.T. feed to the precipitator. 4.6.2.3.1
Preliminary Checks
Under no circumstance shall commissioning proceed until all checks listed in para. 4.5.2.6 have been completed. 4.6.2.3.2
Water Wash and Fluid Coating Systems
a)
Commission the wash and coating systems in accordance with para. 4.5.1 and 4.6.1 Adjust sequence timers.
b)
The precipitator should be washed prior to initial energizing and if specified coated with fluid, allowing correct drainage periods to elapse. (Note : This may be a matter of hours.)
4.6.2.3.3
Automatic Fabric Filter Sections
Commission any automatic fabric filter sections in accordance with para. 4.5.2.4.2, 4.5.2.5 and 4.6.2.2. 4.6.2.3.4
BSBTC-01
Initial Energizing of Precipitator Without Air Flow
(i)
Check that no one is inside precipitator casing, that access doors are closed and that no entry can otherwise be made to the precipitator interior.
(ii)
Cancel and lock out any remote control system for precipitator. 26
(iii) Switch on precipitator. (iv) Check that there is no flash-over problem and that indications from meters and lamps on precipitator control panel are normal. Faulty operation at this stage will probably indicate that a preliminary check has been missed or that water is still present from the initial wash. All safety measures listed in para. 4.5.2.6.3 must be implemented before entry to the precipitator casing. (v)
4.6.2.3.5
Restore full automatic control sequence ready for the establishment of air flow through the precipitator. Application of Air Flow to Precipitator
When air flow is established through the precipitator (see. 4.6.2.4.5) :
BSBTC-01
a)
check that there is no excessive flash-over (say, an average of over five per minute per square metre of the face area). This may be caused, for example, by the lack of correct pre-filtration, no lint screen etc., in main or recirculation ducts, presence of water, incorrect air velocity or excessive H.T. voltage;
b)
an inspection should be made of the de-energized precipitator after a few hours operation with air flow established (see para, 4.6.2.4.5). Absence of dirt staining on any ionizer neutrals, etc., may indicate H.T. disconnection;
c)
the H.T. voltage shall be checked at ionizer and collector sections. Unless otherwise specified the H.T. voltage should be within +3% of the nominal figure specified at the mean declared L.T. voltage. Polarity should normally place positive voltage on the ionizer section to limit ozone generation. Measurement of H.T. voltage shall be by means of an instrument comprising high stability resistance chain with high sensitivity milliammeter in series, or electrostatic voltmeter across one section of the chain. Only a skilled and experienced operator should attempt measurement of H.T. voltage. Great care is necessary to avoid contact with live parts of the meter and no part of the meter or its connections should be touched when it is connected to H.T. components; any such connections should normally be in special H.T. cable to avoid current leakage. Readings should normally be made with the meter placed within the precipitator casing and observed from the outside through the observation window;
d)
the correct total air flow through the precipitator shall be 27
established as part of the procedure for regulation of total air flow (see para. 4.6.2.5.7); e)
the uniformity of air velocity distribution across the face of the de-energized precipitator bank should be checked using an anemometer, after the regulation of total air flow (see para. 4.6.2.5.7); To do this, it will be necessary to override the interlock with the supply fan. It is important to ensure that the precipitator is cleaned and washed before operating the fan with the precipitator de-energized;
f)
single point measurements of indicated velocity should be made at the centre of each 300 mm square of the face area, and where appropriate instrument correction factors shall be applied to each of the readings. The mean indicated velocity is then calculated and each of the point readings is expressed as a percentage of this mean. The percentage variations of velocity must be within the tolerances specified. Upper limits will always be critical and lower limits also in the case of agglomerator/storage type units. Any failure to meet the specified tolerances must be rectified.
4.6.2.4
Initial Running of Electrically Driven Fan Set
4.6.2.4.1
Limit the Load
Wherever possible the first start of any motor should be on light load. With centrifugal fan sets this will normally be achieved by limiting the mass flow by operation of the main damper; a knowledge of the fan characteristic is required so that excessive suction or delivery pressures are not applied to the ductwork system. 4.6.2.4.2
Initial Start
On activating the motor starter, check : (i)
that the direction and speed of rotation of motor shaft are correct;
(ii)
that the motor, drive and fan are free from vibration or undue noise;
(iii) the motor adjustment;
starting
current
for
sequence
timing
(iv) the motor running current on all phases; (v) BSBTC-01
that there is no sparking at commutator or slip rings; 28
(vi) that there is no overheating of motor (see BS 587 and BS 170); (vii) that there is no seepage of lubricant from the housing; (viii) that there is no overheating of the bearings; (ix) that oil rings are running freely; (x)
the reduced speed rev/s and the motor running current on multi-speed motors;
(xi) the rev/s of fan and motor; (xii) the performance of fan belts in case of abnormal vibration. 4.6.2.4.3
Initial Run
A light load run shall be sustained until the commissioning engineer is satisfied from the checks listed in para. 4.6.2.4.2 above and from motor insulation test readings that further load may be applied. Repetitive starting of the motor should be avoided to prevent over-stressing of fuses, switchgear and motor. 4.6.2.4.4
Start at Normal Load
Subsequent to the satisfactory conclusion of the initial light load run, the machine shall be stopped and restarted at normal starting load, and the checks listed in para. 4.6.2.4.2 repeated. Again avoid repetitive starting. 4.6.2.4.5
Running-in Period
After a short run at normal load (a few minutes’ run will normally suffice) flexible connections to terminal units, etc., and terminal filters (which were removed in para. 4.6.2.1) shall be restored to position. Subsequently a running-in period shall be sustained until the fan set is in a reliable continuous running condition that can safely be placed under the normal operation and maintenance regime. The regulation of the air distribution system shall be delayed until the running-in period (which may last some days) is completed satisfactorily. During the running-in period the following work shall be conducted;
BSBTC-01
a)
the dynamic balance of the fan and motor shall be investigated and correct if necessary;
b)
the performance of electrostatic precipitators shall be checked (see para. 4.6.2.3). 29
4.6.2.5
Regulation of Air Flow
Regulation of air flow shall be carried out in accordance with the following procedure. It is applicable to all air distribution systems which require manual regulation, including induction unit systems. Only the method of measurement of air flow at the terminals is particular to the type of system involved. 4.6.2.5.1
Principles
The method consists essentially of working back to the fan from the remote branches by setting the correct proportional air flow at each junction of the system in turn (without regard for absolute values of air flow) and so balancing the system. This done, the absolute valves of air flow throughout the system are then brought to their design values simply by adjusting the main damper only (next to the fan) until the design total air flow rate is established at the fan. This theme is illustrated by consideration of air flow at the junction PQR in a system AZ as shown in Fig. 2 Appendix C. Q is a dampered branch on the duct RP and the required design volumetric air flow rates are shown. With damper Q fully open we may find by measurement that P handles 1.7 m3/s, Q handles 1.3 m3/s; 50% and 75% of their design air flow rates respectively. To balance this junction we would close damper Q until P and Q handle the same proportion of their respective design air flow rates : this may result in a balance of P handling 2.0 m3/s (60% of its design) and Q handling 1.0 m3/s (60% of its design). It follows that B will now be handling 60% of its design rate also, i.e. 3.0 m3/s. Now that damper Q is set, provided that we do not alter any dampers in the system QB downstream of Q or in the system PA downstream of P, we know that whatever the absolute value of air flow at R, this air flow will be divided into the correct design proportions between P and Q at this junction PQR, i.e. two-thirds to P and one-third to Q. As we work back up the system towards the fan, adjusting dampers at other junctions between R and the fan, we will be changing the absolute values of flows in R, P and Q but not the ratios of those flows which remain 3:2:1. Ultimately, when all the junctions have been balanced, we will adjust the main damper to obtain the design absolute air flow rate in the main duct from the fan. The correct total air flow will not be divided by the system as set in the correct proportions at each succeeding junction, until R is reached where 5.0 m3/s will be flowing; this will now divided into 3.3 m3/s in P and 1.7 m3/s in Q exactly as required by the design. BSBTC-01
30
One final point to note is that in practice, when balancing successive junctions, a particular routine is adopted both to avoid accumulative errors and to avoid the need for test points and dampers in ducts between junctions. Referring to Fig. 3 of Appendix C, when A, B have been balanced, A, B and C are all handling the same proportion of their respective design air flow rates. Thus when we come to balance the junction CDE, D can be balanced against A or B and not only against C. In practice A is usually selected as the reference point and the air flows in B, D and F are in turn balanced against the air flow in A. Adjusting the distribution dampers to obtain a proportional balance only, has the important implication that a knowledge is not required at this stage of the absolute values of air flow rate in any part of the system. Hence, the instrument used for measuring the air flow at the terminals or branches of a distribution system needs not necessarily indicate the true value of air velocity or pressure. Therefore, inherent errors in the instrument causing a consistently higher or lower velocity reading than the true value can be ignored; also provided that the same method of measurement is used, factors such as those for effective grille areas are usually self-cancelling and can be disregarded. Not until the entire distribution system has been proportionally balanced will it be necessary to establish the absolute value of the system total air flow rate. 4.6.2.5.2
State of the System and Building
Before starting the regulation of air flow, it is essential that the following conditions are fulfilled : (i)
the building is completed and windows and doors are opened or shut consistent with their normal state; (refer to para. 4.6.2.5.2.v);
(ii)
the duct system is complete and leak-free and in the case of high velocity systems pressure testing is satisfactory;
(iii) the requirements of checks listed in para. 4.5.2 have been met; (iv) normally all main and branch heaters and coolers on supply systems shall be shut off but on all fresh air systems, some heating or cooling may be applied to the main duct only (which handles the total air flow) in order to temper the air delivered to the spaces. Heat gains and losses to the ductwork can be minimized by restricting the difference between duct air temperatures and ambient temperatures; BSBTC-01
31
(v)
4.6.2.5.3
any associated air supply or extract systems which have not been regulated should normally be shut down. For balanced systems it may be necessary to balance supply and exhaust individually against atmosphere (i.e. with doors open), then operates them together for regulation of total system air flow.
Preliminaries to Regulation
To illustrate the regulation procedure a diagram (Fig. 4 in Appendix C) of a typical low velocity supply air system is provided. Note, however, that the procedure for other types of system, including extract systems, is identical to that described here :
BSBTC-01
a)
Check that the dampers on all terminal grilles or diffusers 1, 2, 3, 4 etc., are fully open; also that sub-branch dampers AA, AB, etc., branch dampers A, B, C and main damper M are fully open. All adjustable louvres should be set without deflection, i.e. normal to face of grille. All adjustable cones on diffusers should be set either all in the fully up or all in the fully down position. Set automatic plant mixing dampers FA and RC to one extreme position, i.e. normally either full fresh air or full recirculation.
b)
Measure fan motor amps. Throttle main damper M if necessary.
c)
Measure the indicated air flow rates at all terminal grilles or diffusers 1, 2, 3, 4, etc., preferably using one instrument. Express these initial measurements as ‘Indicated percentages of design air flow’. It is important that the design air flow rates (with which the measured air flow rates are compared) are all based on a common datum of density, usually that of Standard Air or occasionally that of air at design density at fan inlet; during these initial measurements air must be of constant temperature throughout the distribution system (see para. 4.6.2.5.2.iv) although this temperature datum need not necessarily equate with the density datum adopted for the design values of air flow. Note also that variations in wind, stack effect, fan motor voltage, filter resistance, etc., will all have some effect on the performance of the system; for this reason these initial measurements (and also the final measurements, see para. 4.6.2.5.3.d) will be made in one quick, continuous operation so that the readings will normally be truly comparable.
d)
Study the general pattern indicated by the initial readings. 32
The principal points of interest are : (i)
If the indications are that the total air flow rate handled by the system is less than 100% of the design then physical changes to the air handling system will probably be necessary before regulation can begin. The fan performance curve and a measurement of fan motor current will assist in assessment of the total air flow.
(ii)
Are there any obvious faults such as design errors, blockages or leakages indicated, for example, by large differences of air flow readings between apparently similar branches and terminals? Such faults will required correction.
(iii) What are the indicated values of air flow in each branch A, B, C and each sub-branch AA, AB, etc., of the system? (obtainable by totalling appropriate sub-branch values). This will usually determine the order in which branches and groups of terminals are tackled in the regulation procedure. (iv) What is the location of the least favoured terminal (i.e. the terminal with the lowest percentage of design air flow) on which sub-branch AA, AB, etc., of the system? This information is necessary for the regulation of terminals. 4.6.2.5.4 a)
BSBTC-01
Regulation Procedure On any one branch, A, B, or C of the system, the first task is to regulate the terminal dampers on that branch. The order in which this work is tackled will normally be decided from the initial readings described in para. 4.6.2.5.3. The branch A, B or C which has the highest indicated percentage of design air flow will be identified as, say, C and normally tackled first; on that chosen branch C, the Sub-branch with the highest indicated percentage of design air flow will be identified as, say CE and the group of terminals No. 101 to No. 107 on that sub-branch CE will normally be regulated first. Next the group of terminals on the sub-branch with the second highest indicated percentage of design air flow, say, CD, will normally be regulated and so on working towards the sub-branch of the branch C which had the lowest indicated percentage of design air flow during the initial readings. By working in this order measurements of air flow at terminals will be made usually at values which are as near as possible to the design values of air flow. Also, this order of work will give the earliest possible indication that any branch with low initial flow is not going to reach ultimately the design performance 33
required; thus, if necessary, the designer can define physical changes to the system or revise tolerances on air flow without delay.
BSBTC-01
b)
For the regulation of terminal dampers, the group of terminals on each sub-branch of the system will be treated independently of groups of terminals on their subbranches. Thus on sub-branch CE, dampers on terminals No.101 to No.107 will be adjusted to obtain the same indicated percentage of design air flow at each of the terminals within this group No.101 to No.107. (This percentage could be, say, 130%.) On sub-branch CD the dampers on terminals No.94 to No.100 will be adjusted to obtain the same indicated percentage of design air flow at each of the terminals within this group No.94 to No.100. (But this percentage could be, say, 110%). During the regulation of groups of terminals, all the subbranch dampers (and the branch dampers) will be left untouched in the original fully open position.
c)
When all the groups of terminals on this chosen branch C have been adjusted in this way, the next task is to regulate the groups of sub-branch dampers CA to CE on this one branch C only. The sub-branch dampers CA to CE will be adjusted to obtain the same indicated percentage of design air flow at each sub-branch within this group CA to CE. Now for the first time each terminal on branch C will be handling the same percentage of design air flow as every other terminal, in whatever group, on branch C.
d)
When the regulation of both terminals and sub-branch dampers on branch C has been completed, the branch with the second highest indicated percentage of design air flow will be identified from the initial readings as, say, B and the procedure described in para. 4.6.2.5.4.a and 4.6.2.5.4.b repeated for this branch and so on for any other branches leaving the branch with the lowest initial indicated percentage of design air flow (in our case branch A) to the last. Note that through out this procedure branch dampers A, B and C are all left untouched in the fully open position.
e)
When the regulation of terminal and sub-branch dampers has been completed on all branches, the next task is to regulate the branch dampers A, B and C to obtain the same indicated percentage of design air flow in each branch (this could be, say, 115%). Now for the first time each terminal on the entire system will be handling the same percentage of design air flow as every other terminal in the entire system, i.e. 115% throughout.
f)
Finally, when the regulation of all branch dampers has 34
been completed, the main damper M will be adjusted to obtain the desired absolute air flow in the main duct. Each stage of the regulation procedure outlined above is described in detail in the following para. 4.6.2.5.5 to 4.6.2.5.8. Note that the order of working suggested is usually the best one but if necessary a different order can be adopted provided that a basic rule is not broken : at any junction in the system (e.g. the junction of terminal with subbranch or sub-branch with branch, etc.) no damper, which regulates the air flow to one arm of that junction, shall be adjusted until all dampers on either arm downstream of that junction (in the case of a supply system, but upstream of that junction in the case of an extract system) have been adjusted. For example branch damper C shall not be adjusted until branch dampers A and B and subbranch dampers CA, CB, CC, CD and CE have all been adjusted; and again sub-branch damper CE shall not be adjusted until terminal dampers No.101 to No.107, subbranch dampers CA, CB, CC and CD have all been adjusted; and again termin.al damper No.107 shall not be adjusted until terminal dampers No.101 to No.106 inclusive have all been adjusted, etc Note also that the procedure is normally broken down into a series of self-contained operations e.g. one group of terminals is balanced without relation to conditions elsewhere in a large system perhaps on another day. Thus the errors in regulation work due to the effect, over a prolonged period, on system performance of variations in filter resistance, wind effect, stack effect, etc., are minimized. Furthermore, errors due to shorter term variations, for example an instantaneous change in fan motor voltage, are minimized by regulating the air flow at each branch or terminal to balance proportionally with the current air flow at the reference terminal. 4.6.2.5.5
Regulation of Terminal Grilles, Diffusers and Units
Assume it has been decided, in the way described in para. 4.6.2.5.4, to start regulation of terminals at the group No.101 to No.107 on sub-branch CE. The least favoured terminal on this sub-branch has been located (see para. 4.6.2.5.3.d). If this terminal is No.101, the end grille, diffuser or unit, then proceed as follows : (i)
BSBTC-01
Measure the indicated air flow at No.101 terminal which will be used as the reference terminal for this group. Express this measurement as indicated percentage of design air flow rate. This percentage will be used as the 35
lower balancing limit for this group of terminals. (ii)
With the same instrument and using the same method, measure the air flow at terminal No.102 and express this also as indicated percentage of design air flow.
(iii) Compare the indicated percentages of design air flow at No.101 and No.102. (iv) If the indicated percentages of design air flow at the two terminals are within the tolerances specified, the dampers on these two terminals will require no adjustment. (v)
If the indicated percentages of design air flow is outside the tolerances specified, close the damper on terminal No.102 by a judicious amount.
(vi) Measure the indicated air flow now at No.102 and express this as an indicated percentage of design air flow. (vii) Return to No.101 and measure the indicated air flow now at No.101. Again express this as an indicated percentage of design air flow. (viii) Compare the indicated percentages of design air flow now handled by No.101 and No.102. (ix) If the indicated percentages of design air flow at the two terminals are now within the tolerances specified, the terminals are now in balance and the dampers on these two terminals will hence-forward require no further adjustment. (x)
If the indicated percentages of design air flow are still not within the tolerances specified, make a further careful adjustment of No.102 damper, take new readings of indicated air flow at No.102 and No.101 and make a further comparison.
(xi) With practice an operator will normally achieve a balance by one adjustment of No.102 damper. The rule is to close No.102 damper by the least amount necessary to bring the indicated percentage of design air flow at No.102 below the upper balancing limit when compared with the reference terminal No.101. By avoiding overdampering at terminals the rise in air flow at No.101 is kept small, making it easy to judge the value to which other terminals should be regulated. (xii) When No.102 has been regulated to balance with No.101 (the reference terminal), balance No.103 terminal against the reference No.101 in the same way. BSBTC-01
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(xiii) The terminals No.104, No.105, No.106 and No.107 should be regulated, in turn, to balance with No.101 until every terminal on that sub-branch CE has been regulated to balance with No.101; all terminals within this group are now in balance with each other within the tolerances specified and need no further adjustment. (xiv) Note that a change in position of damper No.103 has less effect on the air flow at No.101 (and No.102) than a change in position of damper No.102 would have on the air flow handled by No.101. Therefore, as we proceed further away from No.101, the reference terminal, towards the fan during the course of the regulation procedure, the effect which the closing of a terminal damper has on the air flow at the reference terminal (and all other terminals already regulated) progressively diminishes and it quickly becomes unnecessary to measure the air flow at the reference terminal in every case after a terminal is regulated. (xv) Where the least favoured terminal on the branch is not No.101, but some intermediate terminal, close No.101 damper until it is the least favoured (checking No.101 against the intermediate terminal which was the least favoured), then regulate as described in para. 4.6.2.5.5.i to 4.6.2.5.5.xiv, using No.101 as the reference terminal. (xvi) Regulate the terminals on each of the other sub-branches on this branch C using the above procedure. Note that the terminals on any one sub-branch will be treated as an independent group and will be regulated to balance with a reference terminal within the group, e.g. on sub-branch CD, terminals No.95 to No.100 will be regulated to balance with reference terminal No.94. Throughout this procedure the sub-branch and the branch dampers will all left untouched in the fully open position. (xvii) The group of terminals on each sub-branch is not in a state of proportional balance within the required tolerances. The next step is to regulate the sub-branch dampers in order to bring all the sub-branches on branch C into balance with each other within the required tolerances. 4.6.2.5.6
Regulation of Sub-branches and Branches
The method used is similar to that for the regulation of terminals (see para. 4.6.2.5.5). a) BSBTC-01
Measures the indicated air flow handled by each of the dampered sub-branches CA to CE and express this as an 37
indicated percentage of design air flow. Wherever possible establish this percentage by measuring the indicated air flow from one typical terminal on each subbranch. The typical terminal selected shall preferably exhibit a uniform and stable air flow pattern. Only where the type of terminals on some sub-branches differs from the type of terminal on other sub-branches will measurement of duct air flow have to be made on a sample of the sub-branches which have different type of terminal, so that indicated air flow rates at the differing typical terminals may then be compared. b)
Regulate the sub-branches CA to CE by applying the same procedures described in para. 4.6.2.5.5, i.e. by considering each sub-branch as a terminal grille on the branch duct C, but using closer balancing tolerances. The sub-branch CA will be used as the reference sub-branch for this operation in exactly the same way that terminal No.101 was used as the reference terminal for the regulation of terminal No.101 to No.107. Note that throughout this procedure the branch damper C is left untouched in the fully open position. At the conclusion of the work, the sub-branch dampers will have been adjusted to achieve the same indicated percentage of design air flow (within the tolerances specified) in each of the sub-branches CA to CE.
BSBTC-01
c)
When the regulation of both terminal and sub-branch dampers on branch C has been completed, the next branch, in our case branch B, chosen in the way described in para. 4.6.2.5.4 will be tackled. Once again the first task here is to regulate the groups of terminals on this branch as described in para. 4.6.2.5.5, subsequently to regulate the sub-branch dampers as described in para. 4.6.2.5.6.a and 4.6.2.5.6.b. This procedure will be repeated for all branches in turn, leaving the least favoured branch (in our case branch A) to the last. During this work branch dampers, A, B and C are left untouched in the fully open position.
d)
When the regulation of both terminals and sub-branch dampers has been completed on all branches, the branch dampers A, B and C will be regulated to achieve the same percentage of design air flow at each branch. The method used will be that described for the regulation of subbranches in para. 4.6.2.5.6.a and 4.6.2.5.6.b, i.e. each branch of the system will be though of as a terminal grille on the main duct and the procedure described in para. 4.6.2.5.5 adopted. Once again, wherever possible, establish the indicated percentage of design air flow at each branch by measuring the indicated air flow from a 38
typical terminal on that branch. The branch A will be used as the reference branch for the regulation procedure in exactly the same way that terminal No.101 was used as the reference terminal for the regulation of terminal No.101 to No.107. During this work the main damper M will be left untouched in its original position. All terminals, on whatever branches or sub-branches, are now in a state of proportional balance within the tolerances specified and it only remains now is to regulate the main damper M to achieve the correct absolute air flow rates to all parts of the system. 4.6.2.5.7
Regulation of Total Air Flow Rate
a)
Measure the absolute value of the total air flow rate with pitot tube and manometer, preferably in the main duct. Where a reliable reading cannot be obtained in the main duct, the total air flow can be established by adding the branch (or zone) air flow rates which in this instance shall be measured by pitot tube and manometer.
b)
Compare the measured total air flow with the design value. If necessary adjust main duct damper M until the measured value is within the tolerances specified on the design value of total air flow. Record in full the results of the final measurement. Also measure and record the supply voltage to the fan motor, the motor current and the fan revolutions per second at the time of this final measurement of air flow. Note that with systems which contain fabric filters, or more particularly absolute filters, the dirtiness of the filter may have a significant effect on the total air flow rate. Since the clean filter condition is the only state which can be readily identified and selected on site, measurements of total air flow should be made with filters clean wherever possible and the results obtained should be compared with the design values at this clean filter condition. The static pressure drop across the clean filter shall be measured at the time of the final measurement of total air flow rate and recorded. Differential pressure controls for automatic fabric filters shall now be commissioned in the way described in para. 4.6.2.2.e
c)
BSBTC-01
Where the plant contains auto-dampers for variable proportions of fresh/exhaust/recirculation or face and bypass air proportions, the total air flow measurement and the main damper regulation shall be conducted with the auto-dampers at one extreme of the auto-cycle. It may be necessary to adjust the auto-dampers to obtain the correct proportions of fresh/exhaust/recirculation or face and bypass air when regulating the total air flow. The 39
proportions and the total air flow handled at the other extreme of the auto-damper cycle must then be investigated and if necessary adjustments will have to be made to the proportions at this end of the cycle, whilst maintaining constant total air flow. The characteristics of the auto-dampers will of course determine what change, if any, in total air flow occurs at intermediate damper positions. Note that wherever one air handling system is directly connected with another system, for example, a supply system connected with an extract system via a recirculation duct with fixed or variable mixture dampers, then first proportionally balance the distribution networks of both systems in turn, finally regulate the total air flow in both systems, and the proportions of fresh/exhaust/recirculation air in one combined operation. d)
When the regulation of total air flow is complete, all branches and terminals on the system will be handling the required absolute air flow rates within the sum of the tolerances accumulated during the balancing procedure.
e)
The uniformity of air velocity distribution across the face of electro-static precipitators shall now be checked (see para. 4.6.2.3.5.e and 4.6.2.3.5.f). Using the same technique the air flow distribution at ducted heating and cooling coils may also now be checked.
4.6.2.5.8 a)
BSBTC-01
Conclusion to Regulation Normally after a satisfactory total air flow has been established and recorded, a final check shall be made to ensure that all terminals are in satisfactory balance within the tolerances specified, by measuring in one continuous operation the indicated air flow rates at all terminals, grilles, etc., preferably using one instrument, and by expressing these measurements as ‘indicated percentages of design air flow’. Where there are more than one type of terminal on the system, the appropriate factors must be applied to the readings so that they are all on a comparable basis. The results obtained are not, of course, absolute rates of air flow at terminals - they are merely indicative of the degree of balance between all outlets. However, taken with a leak-free distribution system a satisfactory balance at terminals is a proof that the system has been correctly regulated, and that the terminals are handling the correct absolute air flow rates, (Note : do not make random alterations to damper settings in an attempt to correct any mistakes; any corrective action will require careful planning to minimize the amount of rebalancing needed). 40
b)
After a satisfactory check on system balance, scribe the position of all manual damper operating arms and, preferably, lock them.
c)
Finally, adjustable louvres and cones on outlets, grilles and diffusers shall be set to positions predetermined and specified by the designer.
4.6.2.6
Dual Duct System
a)
Dual-duct systems are sometimes designed to handle 85 to 100% of the total system’s air supply through the cold duct and from 40 to 80% through the hot duct. Balance should be accomplished as follows :
(i)
Set all room control thermostats for maximum cooling, this fully opening the cold air valves.
(ii)
The equipment and main ducts should be checked as outlined in para. 4.5.2.1 and 4.6.2.5
(iii) Determine if the static pressure at the end of the system (the longest duct run) is at or above the minimum required for mixing box operation. Proceed to the extreme end of the system and check the static pressure drop across the box with an inclined draft gauge or magnehelic gauge. The drop across the box should equal or exceed the minimum static pressure recommended by the manufacturer of the box. About 187 Pa (static pressure) is common for the mechanical regulator. Additional pressure is required for the low pressure distribution system downstream of the box. (iv) For those units that are not factory preset, dial the proper setting on the l/s calibrated scale on the mechanical volume regulator or set the air quantity using the pneumatic volume regulator or the pressure differential across the balancing orifice and the manufacturer’s calibration curve. (v)
Balance diffusers or grilles on the low pressure side of the box as described for low pressure systems.
(vi) Change the control settings to full heating and make certain that the controls and dual-duct boxes function properly. Spot check the air flow at several diffusers. (vii) If the designer has taken into account a diversity factor in selecting the main apparatus, it will not be possible to get full flow from all boxes simultaneously as outlined above. BSBTC-01
41
4.6.2.7
Variable Air Volume System
a)
The large variety of variable air volume (VAV) systems precludes a fixed procedure for balancing. However, a field balance of this type of system is an absolute necessity in spite of the many claims for factory-set terminals, which supposedly make balancing unnecessary.
b)
Of the two major types of VAV system, the first is the bypass system where a constant volume of air is handled by the fan with air bypass taking place at the box, and allowing for variation of air being delivered to the terminal. This type of system needs no special attention other than ensuring that the same resistance is installed in the bypass of the box as through the outlets.
c)
The second type of system is true VAV system, wherein the volume delivered by the fan is varied as the boxes vary due to load changes. The variation of air volume can be accomplished by a variable speed drive, an inlet vane damper, a discharge damper or, in some cases, by just allowing the static pressure increases to reduce the air flow rate via the fan curve.
d)
The general procedures for balancing this type of system are as follows :
(i)
Determine the required maximum air volume to be delivered by the supply and return air fans. Diversity of load usually means the volume will be somewhat less than the outlet total.
(ii)
Obtain fan curves on these units and request information on surge characteristics from the fan manufacturer.
(iii) If an inlet vortex damper control is to be used, obtain the fan manufacturer’s data pertaining to the derating of the fan when used with the damper. If speed control is used, obtain information as to maximum and minimum speed that can be obtained with the drive. (iv) Determine from the fan manufacturer the minimum and maximum operating pressures for terminals or VAV boxes to be used on the project. (v)
BSBTC-01
Construct a theoretical system curve with approximate surge area included. The system curve initiates at the minimum inlet static of the boxes, plus system loss at minimum flow and terminates at design maximum flow. The operating range using an inlet vane damper is 42
between the surge line intersection with the system curve and the maximum design flow. When variable speed control is used, the operating range is between (a) the minimum speed that can produce the necessary minimum box static at minimum flow while still remaining in the fan’s stable range and (b) the maximum speed necessary to obtain maximum design flow. (vi) The terminal boxes must then be positioned to the proportion of maximum fan air volume to total installed terminal maximum volume. (vii) The fan should be set to operate at appropriate design speed (increase about 5% for a full open inlet vane damper). (viii) Static pressure should be checked at various terminals throughout the system. A sufficient number should be checked to be representative of the buildings. If a wide variation in statics is encountered, or a number is below minimum, then every box should be checked. (ix) Total air traverse must then be made. (x)
A speed increase must be made if either or both static and volume are low. If the volume is correct, but the static is high, the speed must be reduced. If the static is high or correct, but the volume is low, it is necessary to go over all the terminals and adjust them to the proper volume.
(xi) Item 7) to 10) should be taken with the return exhaust fan operating and the system sets on minimum outdoor air. (xii) Set the outlets to design volume with the VAV box on maximum flow setting. Verify the minimum flow setting. (xiii) Set the return outlets throughout the system. (xiv) The terminals then should be set to minimum, and the inlet vane or speed controller adjusted until minimum static and volume are obtained. (xv) The temperature control and balancing personnel should then cooperate in the final location of the sensor for the static pressure controller. This must be located in the supply duct far enough from the fan discharge to be truly representative of the average static pressure in the system. (xvi) Check the return air fan speed or inlet vane damper to be sure it is tracking with the supply fan to assure proper outside air volume. BSBTC-01
43
(xvii) The system should then be placed on 100% outside air (weather permitting) and supply and return fans checked for power and static pressure. 4.6.2.8
Induction System
a)
Most induction systems used high velocity air distribution. Balancing should be accomplished as follows :
(i)
Perform steps outlined under the basic procedures common to all systems for equipment and main duct capacities.
(ii)
Primary air flow at each terminal unit can be determined by reading the unit plenum pressure with a portable dry type of draft gauge or magnehelic gauge and locating the point on the charts (or curves) of air quantity vs. static pressure supplied by the unit manufacturer.
(iii) Make a spot check of the air distribution by reading the first and last unit on each riser. Do not reset these units. Study these results and then adjust riser dampers to regulate proper flow in each riser. Normally the high capacity risers should be cut back to improve the air flow in the rest of the system. (iv) Beginning on the floor nearest the main supply duct, start the first pass around the system, reading and adjusting as you go. If all unit dampers are open, set the units on the floor nearest the main supply duct about 10% under design capacity. (v)
Normally about three complete passes around the entire system are required for proper adjustment. A final pass without adjustments must be made to record the end result.
(vi) The noise level of the system must be reasonable. If the fan speed is too high, excess static pressure will be supplied to the induction units and the unit dampers and riser dampers will have to be closed further in order to obtain nozzle pressures. The increased pressure drop across the unit damper and riser damper generates noise and contributes to a higher room noise level. To provide the quietest possible operation, the fan speed should be adjusted to the slowest speed that will provide sufficient nozzle pressure to all units with the minimum throttling of all units and riser dampers. (vii) Normally the flow of water in induction unit coils is BSBTC-01
44
automatically controlled to adjust room temperature. Some systems used the primary air source to power the controls and move a secondary air damper for adjusting room temperature. In such a case, it is extremely important that the manufacturer’s minimum static pressure in the plenum of each unit be maintained. (viii) After balancing each supply unit on minimum outdoor air, reposition to maximum, then take additional power and static pressure readings in this position. Comparing power and static pressures in these two positions immediately indicates any changes necessary in the return system to accomplish the design requirements. (ix) Adjust the air terminal outlets for a proper distribution pattern. Make a final trim of air balance after the building is occupied and in normal use. 4.6.2.9
Extract System
The extract system can be balanced the same way as supply system, making modifications as necessary. 4.6.3 Refrigeration Systems 4.6.3.1
General
Testing & commissioning of refrigeration system will normally be carried out by a skilled and experienced person but the following points need careful observations. Essential features are described in four parts : (i)
Reciprocating Compressor Systems See para. 4.6.3.2.
(ii)
Centrifugal Compressor Systems See para. 4.6.3.3.
(iii) Absorption Systems See para. 4.6.3.4. (iv) Screw Compressor Systems See para. 4.6.3.5. 4.6.3.1.1. System Cleanliness a)
The chilled water, and the condenser water systems should be flushed through to clean them, generally following the procedures given in para. 4.5.1.1. Isolate items which are particularly sensitive to dirt,
BSBTC-01
45
including shell and tube evaporators and condensers, pumps and spray nozzles and automatic water valves. Where appropriate, remove strainer screens, cooling tower basins, tanks and other equipment which may have accumulated deposits during manufacturing or installation, and shall also be isolated and flushed independently. b)
Check the following items for cleanliness.
(i)
Air intake screens;
(ii)
Fan chambers of condensers and cooling towers;
(iii) Fan internals; (iv) External heat exchange surfaces of air-cooled condensers, evaporative condensers and cooling towers; (v)
Sensing elements;
(vi) Cooling tower basins, evaporative condenser tanks and chilled water tanks; (vii) Compressor, motor and drive; (viii) Safety and control devices; (ix) Drains and overflows. 4.6.3.1.2 a)
State of System Water System
For chilled water and condenser water systems, carry out the T & C procedures as listed in para. 4.5.1 and 4.6.1 with the following additions : Check : (i)
that the cooling tower fill is complete and secured;
(ii)
that where chilled water tank is provided the tank lid is fitted and secured;
(iii) the valved connection (where specified) for blow-down from cooling towers and evaporative condensers; (iv) that any splash guards for cooling towers and evaporative condensers are fitted. b) BSBTC-01
Air System 46
For air handling systems and any airways associated with the air-cooled condensers, evaporative condensers and cooling towers. Check : (i)
that the airways are clear, including adequate free area of openings which serve the fans;
(ii)
that the condenser heat exchangers are installed correctly in relation to air flow;
(iii) where applicable, the damper free movement, clearances, seating, pinning to damper spindles, relative positions of blades in multi-leaf dampers; (iv) that dampers are secured in open position with, where motorized, the actuator disconnected; (v)
the airways including builders’ work ducts for airtightness, noting particular seals at equipment, access doors, flexible connections, and junction of metal and builders’ work ducts.
c)
Refrigerant System
Check : (i)
that pipework is complete and secured;
(ii)
that the thermostatic expansion valve (or float level device) are fitted : thermal bulb are correctly fitted and secured, external equalizer (where appropriate) are fitted;
(iii) that the safety and control devices are fitted : low pressure cut-out, high pressure cut-out, oil pressure cutout (where fitted), and where specified chilled water low temperature thermostat, low water flow safety device and any protective solenoid valves; (iv) that the liquid line strainer, isolating valves as specified, sight glass with moisture indicator and drier are fitted; (v)
that the suction, discharge and oil pressure gauges with isolating valves are fitted and isolated from the system;
(vi) that purging and charging connections are fitted; (vii) that if liquid receiver is provided, the capacity and associated work to be checked, and where required in the Particular Specification surveyor’s certificate to be BSBTC-01
47
provided before commissioning. d)
Check of Water System Before Filling
Carry out checks as appropriate as described in para. 4.5.1.3. 4.6.3.1.3 a)
Mechanical Checks Fans
Carry out checks as given in para. 4.5.2.4.1 b)
Compressors
Check : (i)
the external cleanliness;
(ii)
that all components, bolts, fixings, etc., are secured;
(iii) that the compressor shaft is free to rotate; (iv) the level and plumb of compressor and motor shaft and slide rails; (v)
the anti-vibration mountings for correct deflection;
(vi) that correct drive is fitted; (vii) the securing and alignment of pulleys and couplings; (viii) the belt tension and match; (ix) that drive guards are fitted, the access for speed measurement is provided and nipple extension for motor lubrication is provided; (x)
the correct oil level in compressor;
(xi) that the compressor unloading gear is fitted (if specified); (xii) any special arrangements for motor cooling; oil cooling where appropriate; (xiii) that vibration eliminator and muffler are fitted. c)
Drives
For gear boxes and special mechanical drives pulley/belt, direct or flexible couplings for compressor or large cooling tower fans. BSBTC-01
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Check : (i)
that the lubrication and pre-lubrication are correct before starting;
(ii)
that drive mounting are secured;
(iii) that all shafts are correctly aligned; (iv) for free rotation. 4.6.3.1.4. Electrical Checks a)
With all Electrical Supplies Isolated
Check : (i)
the local isolation of motor and control circuits;
(ii)
that there are no unshrouded live components within the panels;
(iii) that the panels and switchgear are clean; (iv) that the motor and surrounding areas are clean and dry; (v)
that the transit packing has been removed from contactors and other equipment;
(vi) that there is no mechanical damage to switchgear or water heaters and that their thermostats are of a suitable range to operate at ambient temperature (see para. 4.6.1.2); (vii) that all mechanical checks on the pump and motor of valve are completed (see para. 4.5.1.4); (viii) that all the connections are tight on busbars and wirings; (ix) that the internal links on the starter are correct; (x)
that all the power and control wirings have been completed in detail to the circuit diagram (paying special attention to circuits for star-delta connected or specially wound motors);
(xi) that the fuse ratings are correct; (xii) that the starter overloads are set correctly in relation to the motor name-plate full load current; (xiii) that the dashpots are charged with the correct fluid and the time adjustments and levels are identical; BSBTC-01
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(xiv) that insulation tests on the motor have been performed satisfactorily; (xv) that the adjustable thermal cut-outs are set correctly (check manufacturers’ test certificates); (xvi) that all the cover plates are fitted; (xvii) that the wiring from all safety devices (high pressure cutout, low pressure cut-out, etc.) and liquid line solenoid valve are completed; (xviii)
that the compressor crankcase heater(s) is/are fitted and the wiring is completed.
b)
With Electrical Supplies Available
(i)
Check that the declared voltage is available on all supply phases.
(ii)
Where motor powers are substantial or reduced voltage starting or complex interlocks are involved, the control circuit logic and the starter operation shall be tested before the motor is rotated. The supply should first be isolated; then by the withdrawal of two power fuses or the disconnection of cables followed by the reinstatement of supply to the control circuit alone; the control circuit shall be activated and starter operation observed. In addition to the compressor starter operation, check for satisfactory operation of any electrical controls associated with compressor starter operation such as liquid line solenoid valve, electrical timing heater on the oil failure control (in this case check for satisfactory operation and then temporarily disconnect), and capacity unloading if initiated electrically.
(iii) Where automatic sequenced starting for the whole of the refrigeration plant and associated chilled water and condenser water pumps has been specified, check that the sequence is correct in order and timing. Adjust timers, check for clean operation of all contactors, relays and interlocks. Finally open isolators, reset or reconnect any device as appropriate, reinstate power connections and close isolators. (iv) Where small motors have direct on-line starting and simple control circuits, the starter operation, etc., should be checked when first starting the motor. 4.6.3.2. BSBTC-01
Reciprocating Compressor System 50
4.6.3.2.1
Pressure and Leak Testing
Refrigeration system working and test pressures are defined in BS 4434, Section 7. a)
Factory Assembled Packaged Units
(i)
In the case of these units, pressure and leak evacuation and dehydration and charging, either as a small holding charge or the full amount, should have been carried out at the factory.
(ii)
Observe pressure gauge readings. If the gauge readings are unsatisfactory, bearing in mind the amount of charge supposed to be in the system and the ambient temperature, the whole programme of pressure testing, evacuation and charging must be carried out again.
(iii) If the gauge readings are in order, then pressure testing and evacuation should not be necessary. Where the system has a holding charge, additional charging will be necessary. In any case a check leak-test on all joints as for ‘built-up’ systems is advised. b)
Built-up Systems Pressure and leak testing is normally carried out on completion of the system, before pipework is insulated and before condenser is filled with water.
(i)
Charge the system with a small amount of the refrigerant being used in the circuit (to, say, a gauge pressure of 1.4 bar). The refrigerant acts as a tracer for leak detection purposes.
(ii)
Charge the entire system to the desired test gauge pressure (typically 14 bar for R-22 or R502) in accordance with manufacturer’s instructions using a cylinder of dry nitrogen.
(iii) Pressure should be applied to compressor to test the vulnerable oil lines, etc. Precautions to be made on applied pressure to avoid damages to the shaft seal. (iv) Check all joints for leaks by using a soap solution “bubble” test. After this, check the entire refrigerant system for leaks with a halide torch or electronic leak detector. Pay particular attention to gasket joints, bolt heads and nuts, sight glasses, welded joints, parting lines on castings, gauges and gauge connections, relief valves, BSBTC-01
51
evaporator and condenser water boxes. On hermetic units pay particular attention to motor terminals; on open machines check the shaft seals. (v)
If leaks are discovered the gas and refrigerant in the system must be exhausted, leaks remedied, and the system recharged and retested.
(vi) Repair any leaks found on the system. Leaks must not be repaired while the system is under pressure. (vii) When the system is found to be leak-free allow to stand for a minimum of 24 hours under pressure. If no pressure drop occurs (allowing for effect due to changes in ambient temperature) the system is ready for evacuation. (viii) Relieve test pressure to atmosphere, reconnect all lines and reinstate all items removed or isolated prior to pressure testing. 4.6.3.2.2
Evacuation and Dehydration This will be carried out by specialists.
4.6.3.2.3
Associated Air Systems
a)
Setting to work and adjusting air handling plant shall be carried out in accordance with para. 4.5.2 and 4.6.2.
b)
For systems employing direct expansion air coolers check that the commissioning of the main system air distribution plant has progressed sufficiently through para. 4.6.2 to enable some measure of heat exchange to take place at the cooler, to allow limited running of the refrigeration plant for initial commissioning purposes. It is preferable that the whole of the para. 4.6.2 work has been carried out. For air handling plant on the condenser side of the refrigeration plant, carry out the relevant parts of para. 4.5.2 and all of para. 4.6.2.4.
4.6.3.2.4
Charging
This will be carried out by specialists. 4.6.3.2.5 a)
Setting to Work and Adjusting Procedures
This section defines the procedures to be carried out in order to achieve a refrigeration plant working satisfactorily, properly charged and lubricated, with all controls operating and safety BSBTC-01
52
devices effective. All procedures as outlined in para. 4.6.3.1 and 4.6.3.2.1 to 4.6.3.2.4 should be completed before commencing this section. Chilled water and condenser water systems shall have been checked in accordance with para. 4.5.1 and the setting to work procedures in para. 4.6.1 shall have been proceeded at least to a point where sufficient water flow is available to enable full capacity conditions of the refrigeration plant to be checked. b)
System Checks
Before operating the compressor for the first time (the compressor will probably have been operated briefly during the charging operation) a further visual check should be carried out on the complete system, and in particular all refrigeration safety controls should be put through their complete cycle of operation. (i)
Set refrigeration pressure controls in accordance with manufacturer’s instructions or ensure that factory settings have not been disturbed. Adjust compressor low pressure switch to cut-in whenever suction pressure rises above desired gauge setting, with the differential set as wide as possible to prevent short-cycling. (Typically, for R-12 : cut-in 2.4, cut-out 1.0 bar R-22 : cut-in 5.0, cut-out 3.0 bar) Adjust high pressure switch to recommended gauge settings. (Typically, for R-12 : cut-out 12.5 bar R-22 : cut-out 18.5 bar) Adjust oil pressure switch to recommended setting. (Normally usable oil pressure gauge reading minus suction pressure gauge reading equals usable oil pressure.) (Typically, cut-in 1.25, cut-out 0.85 bar above suction pressure.) Note : On start-up a time delay relay permits compressor to operate for a predetermined period (usually above 90 to 120 seconds) while the required oil pressure differential above suction pressure is being established. On water chillers check the setting of freeze protection thermostat (whenever possible this should be fully checked by immersing the bulb and a thermometer into a water and ice mixture) in chilled water piping circuit and/or freeze protection low pressure switch, also the
BSBTC-01
53
operation of evaporator flow switches and back pressure regulators (where fitted). (ii)
Ensure all sequence and safety interlocks are operating correctly, i.e. evaporator fans, chilled water pumps, condenser water pumps, tower fans (or evaporative condenser fans and pumps, or air-cooled condenser essential to its operation stop for any reason. Depending on the wiring arrangements used, some manufacturers’ handbooks will show to what extent operation of control or protective devices can be simulated by electrical means.
(iii) Make provision for taking refrigerant temperature at a point as close as possible to the remote bulb of the thermostatic expansion valve at the evaporator suction outlet, to enable proper superheat measurement to be made. The suction pressure should be read at a gauge installed in the back-set port of the compressor suction valve and converted to temperature reading using the refrigerant table. The difference between the thermometer reading at evaporator suction outlet and the temperature calculated from suction pressure is the superheat (most air conditioning installations have superheat settings of about 5oC or 6oC). (iv) This method does not take into account any pressure drop in the low side of the system (suction lines are normally designed for 0.07 bar maximum pressure drop). If abnormal pressure drop is suspected, steps should be taken to measure it and determine the reason. (v)
Check the condensing system to ensure design air and/or water quantities at required temperatures are available to enable desired high side pressure to be maintained. Particularly check that the condenser water valves are open and the pressure or temperature actuated automatic valves (where fitted) are operative.
(vi) Check the associated thermostatic control system as described in para. 4.6.4. Set the controlling device (e.g. chilled water, room air, or return air thermostat, or pressure switch, or humidistat) to the desired level. (vii) Immediately prior to commencing a continuous test run on the refrigeration system. Check : BSBTC-01
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that all refrigerant circuit shut-off valves are in open position, except for bypass valves; especially ensure that the condenser liquid line valve is open; that all chilled water and condenser water circuit valves are in correct position; that the compressor suction and discharge valves are open. Oil, suction and discharge pressure gauge throttling valves are open; that the solenoid stop valves of evaporator are working on magnetic coil control; that the lubricating oil is visible (at centre, or above) in sight glass on compressor sump; that electrical supply has been available to the crankcase heater and that the heater has been operating. In a cold plant room a period of at lease one hour of operation should elapse prior to running to enable the heater to boil off any refrigerant. (viii) Depress reset buttons on refrigerant pressure control(s), oil pressure control and freeze protection thermostat and/or freeze protection pressure switch. c)
Start-Up
(i)
Turn the compressor over several times by hand from the drive coupling (or vee-belts), and ensure there is free movement of all rotating parts. Disconnect drive coupling or vee-belt. Check the correct direction of motor.
(ii)
Start on ’manual’ control of the chilled water pump (or relevant fan) and condenser water pump and cooling tower fan (or condenser fan or evaporative condenser fan and pump). If controls are arranged for sequenced ‘auto’ start only, proceed straightly to automatic start of the complete plant. Correct any operating difficulties before proceeding.
(iii) Start and stop the compressor several times (at about 10 second intervals) and observe :
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the direction of rotation of compressor;
-
that motor, drive, and compressor are free from vibration or undue noise; 55
-
the motor starting current;
-
the oil and refrigerant pressure gauges. Take care not to exceed permissible starts/hour of switchgear. On plant with both ‘manual’ and ‘auto’ selection, after two or three successful ‘manual’ operations change over to automatic control.
d)
Shut-Down
(i)
If the plant has ‘auto’ controls, operate an automatic shut down. Check that all sequencing and any special shut down requirements are operated satisfactorily.
(ii)
If the plant is arranged for manual control, proceed through the correct relevant sequence to shut the complete plant down; observe whether all automatic or safety features are operated satisfactorily.
(iii) In either case above note whether anything incorrect occurs during the shut down cycle (such as noise, vibration, or unexpected pressure variation). e)
Running-In When all of para 4.6.3.2.5.a to 4.6.3.2.5.d have been satisfactorily completed the complete system should be placed in operation and allowed to run normally for at least 72 hours. It is recommended that the installation be continuously supervised by a competent person for at least half of this running-in period. The oil level in the compressor must be watched closely during this entire period. The compressor must not under any circumstances be allowed to run short of oil. During the running-in period, try to ensure that there will be sufficient load to keep the plant running. This may mean the provision of an artificial load. Check and observe the following features, and adjust if necessary. A log book for recording all operation information at every hour must be made available.
(i)
BSBTC-01
Superheat setting of the thermostatic expansion valve using the method given in para. 4.6.3.2.5.b.iii. Checks must be carried out under conditions approximating to design conditions (i.e. average or maximum load, but not light load) and satisfactory condenser pressure; otherwise deceptive values of superheat will occur due to incorrect operating conditions and not incorrect setting of the valve control. 56
Do not alter superheat setting until it is certain that the reset of the system is operating satisfactorily. If under normal operating conditions incorrect values of superheat are found, gradual adjustment of the control setting (as given in the manufacturer’s instructions) and rechecking of the superheat value should be made. (ii)
All operating temperatures and pressures (in refrigerant cycle and chilled water and condenser water circuits) are under normal running conditions. Refrigerant flows at sight glasses. Bubbles indicate refrigerant shortage and possible leak.
(iii) Amperage and voltage readings of all motors, any sparking at commutator or slip rings should be recorded. (iv) Check the system for refrigerant leaks. This should be done at least twice during the running-in period. When these checks have been made and the plant is running satisfactorily and steadily, check the operation and calibration of control and protection devices. (v)
The operation and control of the refrigeration plant by the primary control device (thermostat, etc.). The actual control of the condition (temperature, etc.) by the device will be checked as given in para. 4.6.4. This check concerns the ability of the device to stop and start the refrigeration plant in the required manner. This operation should be achieved by a gradual reduction of the cooling load. This should be done solely so that there is ample time to note any extended sequence of events. When the refrigeration plant has stopped, load can be gradually increased, so as to observe the automatic starting up sequence. The cycle can be repeated more quickly, but there is no merit in changing the load more quickly than would occur naturally. An unnaturally rapid change of load could occur too quickly for the satisfactory operation of protection devices and damage the plant.
(vi) During this load changing procedure, the satisfactory operation of the liquid line solenoid valve, compressor capacity control system, unloaded compressor start-up, and automatic pump down, where these facilities are specified, should be observed. (vii) Low pressure cut-out. Close the liquid line shut off valve (isolating valve on liquid receiver or cause the liquid line solenoid valve to close). The compressor will then reduce pressure in the evaporator. Check that the low pressure cut-out operates at the suction pressure recommended. Watch the suction gauge carefully, do not BSBTC-01
57
allow the suction pressure (particularly with water chillers) to fall more than about 0.1 bare below the recommended setting. Open the valve and check the pressure at which compressor cuts in. Isolating valves should be opened and closed as slowly as possible. (viii) High pressure cut-out. Gradually reduce the flow of the condensing medium (by closing a valve on condenser water circuit, or restricting the air flow to or from the aircooled condenser). This will cause the condenser pressure to rise. Check that the high pressure cut-out operates at the condenser pressure recommended. Watch the pressure gauge carefully, do not allow the condenser pressure to rise appreciably above the recommended setting. Slowly restore flow of condensing medium and check the pressure at which compressor cuts in (with manual rest it will be necessary to depress reset button). (ix) Condenser pressure control, where fitted. During this period if possible note the operation of condenser pressure control under either naturally occurring low external temperature conditions (at night perhaps) or where possible simulated conditions by say on a multicompressor plant feeding the whole of the condensing capacity to one machine. The aim is to provide conditions which would lead to a drop in condenser pressure and then establish that the control devices operate to maintain condenser pressure steadily at the correct value. (x)
Evaporator pressure regulating valve, where fitted. Reduce the cooling load, so that suction pressure tends to drop. Observe the evaporator pressure (if a special gauge has not been fitted, fit one temporarily at the evaporator on the evaporator side of the valve); this should not fall below the required value, even though the suction pressure drops to cut-out level.
(xi) With the assistance of manufacturer’s recommendation check the operation of any other special control or operating devices such as low water temperature control, low water flow control, or hot-gas by-pass circuit controls. Where any device is installed for protection of the plant, care must be exercised when checking so that should the protective device fail to operate, the plant is not allowed to continue to run and damage itself. (xii) Condenser pressure against condenser temperature. If pressure is excessive this indicates presence of air or other non-condensable gases. Stop the plant, allow the condenser to cool, then purge. Restart the plant, recheck, and re-purge if necessary. BSBTC-01
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(xiii) All mechanical equipment should be checked for excess heat, noise and vibration. f)
First Inspection after Running-In This cannot be carried out until the plant has been in operation for at least 72 hours. During the running-in period lubricating oil will have had time to accumulate in any low spots, or oil loops, as at the bottom of double-riser piping circuits. Hence, the amount of oil to be retained in the system outside of the compressor should be stabilized by this time, and the level in compressor should be relatively constant. In addition, scale or foreign material in refrigerant lines and water circuits should have been loosened and collected in strainers. By the end of the running-in period any improper adjustments or sources of potential trouble should be apparent.
(i)
Recheck the compressor oil level. If low, wait further three or four hours to see that returning oil does not restore proper level. If level remains low, further lubricating oil should be added to maintain correct level. Ensure that the compressor crankcase heater is working so that oil level is not high due to refrigerant distilling into the oil.
(ii)
Remove test gauges and plug tappings.
(iii) With compressor stopped, check the compressor shaft seal for refrigerant leakage. (iv) Check the alignment and lubrication of compressor motor. Check and tighten as necessary the holding-down bolts. (v)
Check the drive belts for proper tension and alignment.
(vi) Check the dryer. If there is presence of appreciable moisture, change the dryer. g)
Final Inspection after Running-In This should be carried out after the system has been in operation for about one week (not before).
(i) BSBTC-01
Drain the compressor crankcase and clean the interior with approved cleaner. 59
(ii)
Recharge the compressor with new clean compressor oil which is of exact type and grade specified by the manufacturer.
(iii) Tighten bolts in coupling between compressor motor (or adjust belt drive as necessary). (iv) Change the dryer element. 4.6.3.3
Centrifugal Compressor System
The complete plant must prior to running, have been pressure and leak tested, evacuated and dehydrated, and the system charged with refrigerant and lubricating oils by the specialists. The charging operation is normally carried out by the specialists on site. In addition, cleanliness, stage of system and mechanical and electrical components must be checked. On open type centrifugal ensure transmission lined up in accordance with manufacturer’s instructions. Check : (i)
that evaporator and condenser shells are correctly levelled;
(ii)
that all flanged connections are correctly aligned and tightened, with proper gaskets in place;
(iii) that liquid line and float valve assembly are complete; (iv) that vibration isolation to compressor is provided in accordance with manufacturers’ recommendations; (v)
that motor cooling connections are complete;
(vi) that the purge unit and small-bore accessory piping are completed, including cooling water connections where specified; (vii) that oil sump accessories and connections are installed; (viii) that control gauges and tubing are completed; (ix) that temperature control bulbs are correctly located, space between bulb and well is filled and suitable heat conducting fluid, and capillary tubes are free from damage or distortion. 4.6.3.3.1 BSBTC-01
Pressure and Leak Testing 60
Refrigeration system working and test pressures are defined in General Specification (Clause 20.08 - Pressure Testing for Refrigerant Systems). a)
Factory Assembled Units These are factory pressure and leak tested, often insulated, and delivered to site with a holding charge of refrigerant (usually only R-12 and R-113 systems).
(i)
Observe pressure gauge readings. If gauges register zero unit may have been damaged in transit and holding charge lost, in which case the whole programme of pressure and leak testing must be carried out again.
(ii)
If gauge readings are in order (according to manufacturer’s figures) then a leak test should be carried out around all joints. Alternatively, units may be despatched under vacuum and in this case the manufacturer’s recommended procedures should be followed.
b)
Site-assembled Units Pressure and leak testing should be carried out on completion of the installation, before the unit and the immediately adjacent pipework connections are insulated, and before condenser or evaporator is finally filled with water. A cylinder of dry nitrogen and a small amount of refrigerant of a type recommended by the unit manufacturer should be used to pressure test the system. Refrigerant R-12 is frequently used for this purpose and also serves as a tracer for leak detection, although the working refrigerant may be of a different type.
(i)
Where the required test pressures exceed the allowable pressures on certain items, remove or isolate these components. Ensure the system is suitably sealed to enable the pressure testing to be carried out.
(ii)
Where the purge unit is subjected to a higher operating pressure than the remainder of unit, it should be isolated and tested separately at a higher pressure.
(iii) Charge the purge unit to the desired test pressure with proper type of refrigerant in accordance with manufacturers’ instructions. (iv) Check the entire purge unit for leaks using a halide torch or electronic leak detector. Tap all joints with a mallet BSBTC-01
61
and remove any flux that may be adhering to them. (v)
Repair any leaks and retest the unit. Leaks must not be repaired while the system is under pressure.
(vi) On satisfactory completion of test, relieve test pressure (by opening valves in connecting pipework to main unit) and remove charging apparatus. (vii) Reinstate any items previously removed or isolated. (viii) To charge and leak test the entire unit, first connect a cylinder of refrigerant as recommended by the unit manufacturer to the charging valve (R-12 is typically used for leak testing). (ix) Charge enough refrigerant into the system to produce a pressure as recommended by the unit manufacturer for leak test purposes (typically 0.14 bar gauge pressure for R-11 system). (x)
Close the charging valve and remove the refrigerant charging apparatus.
(xi) Connect a cylinder of dry nitrogen to the charging valve on the unit and charge to the desired test gauge pressure (typically 1.0 bar for R-11 system). Suitable nitrogen injection pressure reducing valve is fitted. (xii) Close the charging valve and remove the charging equipment. (xiii) Check all joints for leaks by using a soap solution “bubble” test. After this, check the entire refrigerant system for leaks with a halide torch or electronic leak detector. Pay particular attention to gasket joints, bolt heads and nuts, sight glasses, welded joints, parting lines on castings, gauges and gauge connections, relief valves, evaporator and condenser water boxes. On hermetic units pay particular attention to motor terminals; on open machines check the shaft seals. (xiv) Repair any leaks found on the system. Leaks must not be repaired while the system is under pressure. (xv) When the system is found to be leak-free allow to stand for a minimum of 24 hours under pressure. If no pressure drop occurs (allowing for effect due to changes in ambient temperature) the system is ready for evacuation. BSBTC-01
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(xvi) Relieve test pressure to atmosphere, reconnect all lines and reinstate all items removed or isolated prior to pressure testing. Note :Some manufacturers may permit R-11 and R-113 machines to be pressurized using the purge pump. R-114 machines may be pressurized with dry nitrogen, a typical test gauge pressure being 2.2 bar. 4.6.3.3.2
Evacuation
This will be carried out by specialists. 4.6.3.3.3
Associated Air Systems
Check in accordance with para. 4.6.3.2.3 4.6.3.3.4
Charging
The procedure to be adopted will vary according to the make of unit, type of refrigerant and will be carried out by specialists. 4.6.3.3.5 a)
Setting to Work and Adjusting Procedures After satisfactory completion of procedures in para. 4.6.3.1. and 4.6.3.3.1. to 4.6.3.3.4, and before operating the centrifugal compressor for the first time, a further visual check shall be carried out on the complete system. The chilled water and condenser water systems must have been thoroughly checked in accordance with para. 4.5.1 and 4.6.1, and be ready for operation. For this section to be carried out completely, some load on the chilled water plant (probably at least 50 per cent) is necessary.
b)
System Checks
(i)
Controls With all electrical supplies isolated, check wire connections for tightness and fuses for correct size. With centrifugal compressor motor electrically isolated by removal of power fuses (or by disconnection of power leads), check that chilled water pumps, condenser water pumps, cooling tower fans, and centrifugal refrigerant plant oil pump operate in the sequence required, rotate in the proper direction, and that flow rates and pressures are set to the required levels.
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Ensure that centrifugal compressor motor will be “locked-out” if other equipment essential to its operation stops for any reason. Set each control and safety device in accordance with manufacturer’s instructions, or ensure that factory settings are correct and have not been disturbed. The complete control system shall be checked out generally in accordance with para. 4.6.4. Check the settings and the functional operation (by raising and lowering the temperature of water at sensing element if necessary) of following items as appropriate to system under consideration : -
Load sensing device, usually chilled water thermostat.
-
Inlet guide vane operator.
-
Load limit relay.
-
Pneumatic/electric switches.
-
Oil temperature control (this may require check on operation of sump cooling water solenoid valve and sump heater).
-
Oil pressure relief valve.
-
Oil filter pressure cut-out switch.
-
Low pressure oil cut-out switch.
-
High pressure oil cut-out switch.
-
Chilled water low temperature cut-out.
-
Refrigerant low temperature cut-out.
-
Cooling tower thermostat and condensing water controls.
Also fitted may be :
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Time delay relay on inlet vane operator.
-
Vane closed switch.
-
Time delay relay on oil pump (to prolong running on shut down cycle).
-
Timers in main motor starter. 64
-
Thrust bearing and transmission bearing high temperature cut-out thermostat (on compressor).
-
Timer (to limit number of starts per hour) and recycling device.
-
Motor winding high temperature cut-out switch.
-
Flow switches (chilled and/or condenser water). Check for satisfactory operation of pilot lights and reset buttons.
(ii)
Purge Unit Compressor purge system Check :
-
the oil levels in compressor sump and oil separator sections;
-
the operation of high pressure control;
-
the operation of temperature control and purge heater;
-
the alignment of motor and compressor shafts, drive belt adjustment, and lubricate compressor motor bearings in accordance with manufacturer’s instructions;
-
that the system isolating valves are in correct positions (open/closed).
(iii)
Thermal purge system Check in accordance with manufacturer’s instructions and ensure all valves are in correct position (open/closed).
(iv)
Start-Up Ensure all electrical switches and starters are in “off” position and supplies are isolated. Replace any fuses or leads removed during para. 4.6.3.3.5.b.i. Ensure all water valves are in proper position. Place chilled water pump, condenser water pump, cooling tower fan, refrigeration machine oil pump and purge system starters in “auto” position and close isolators.
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Start the chilled water and condenser water pumps and cooling tower fans. Energize the control circuits. Start the oil pump and allow the main compressor to run. Check the compressor impeller rotation. If incorrect, stop immediately, electrically isolate, and reverse any two of the three phase connections. Recheck. Start the purge system. -
Compressor type. Energize the purge heater and after 30 minutes, start purge compressor, or in accordance with manufacturer’s instructions. The longer in time is better.
-
Thermal type. Start in accordance with manufacturer’s instructions. The centrifugal refrigeration system now should be in full operation.
(v)
Shut-Down Stop the compressor and then the chilled water pumps, condenser water pumps and cooling tower fans in sequence. Listen for any unusual sounds from compressor or transmission housing during “coast-down” period. Check that the operation of oil pump continues until time delay relay causes it to stop.
(vi) Running-In Restart plant in accordance with para. 4.6.3.3.5.iv. Check the oil pressure and temperature. Check the operations of refrigerant agitator solenoid valves (where fitted) in relation to vane motor crank angle. Adjust the motor overload trip mechanism in accordance with the instructions of the compressor and start manufacturers. Caution : Do not allow motor to operate in overloaded condition beyond the time permitted by the manufacture BSBTC-01
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(typically 60 minutes at 105 per cent of full load amperage). Adjust low limit relay to manufacturer’s instructions. Check for satisfactory operation of low temperature control. Check for satisfactory operation of refrigerant low temperature cut-out. Check the operation of high pressure cut-out (if necessary isolated switch and use metered air supply). Take gauge and other readings and compare with design figures, typically :
4.6.3.4
-
Evaporator pressure.
-
Condenser pressure (measure water temperature if necessary).
-
Purge drum pressure.
-
Oil sump temperature.
-
Oil level.
-
Chilled water and condenser water temperatures.
Absorption System
The absorption refrigeration machine usually factory assembled though, certain necessary items may be installed on site. Prior to running, the unit must be pressure and leak tested, evacuated and charged with primary refrigerant (usually lithium bromide solution), lubricating oils and chemicals. The charging operations are usually carried out on site. In addition, cleanliness, stage of system and mechanical and electrical components must be checked. Check : (i)
that the unit is correctly installed and levelled;
(ii)
that the chilled water and condenser water circuits are complete and are ready to operate. Water treatment is available if specified;
(iii) that the steam and condense, or hot water piping system are complete with adequate pressure gauges, BSBTC-01
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thermometers, and test points; for steam piping system: pressure relief valve and safety valve are correctly set; trapping arrangements are satisfactory; control valve is correctly installed; for hot water piping system: control valve is correctly installed; (iv) that steam, or hot water, is available at rated pressure/temperature; (v)
that auxiliary water piping and drains are completed (as may be required for pump motor, cooling and lubrication during start-up periods);
(vi) that all electrical wiring, to starters, motors, and controls are completed; (vii) that pneumatic controls (where used) are installed, pneumatic piping is completed and tested, air pressure is available; (viii) that all gauges and thermometers (or test points) are installed on water inlets and outlets to evaporator, absorber and condenser; (ix) that dry nitrogen and refrigerant (general R-12) are available for pressure and leak testing (when carried out on site); (x)
that lithium bromide solution, chemicals and lubricating oils are available for charging, together with necessary equipment.
(xi) that for the system to be operated and properly commissioned it is usually necessary to have at least 75 per cent of the cooling load available. (xii) In addition, in conjunction with the manufacturer’s representative, ensure that phase sequence of power supply is checked and that connections are properly made before hermetic pumps are operated (some types of machines). Note : The absorption unit is usually shipped to site as a factory assembled package, having been evacuated, leak tested, and charge with dry nitrogen under a slight positive pressure. Various items of accessory equipment such as purge pumps, control panels, etc., may be installed on site. In this case, final leak testing, evacuation, charging, and start-up of the unit are usually carried out by, or BSBTC-01
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under the supervision representative.
of
the
manufacturer’s
Alternatively, the absorption unit may be factory assembled, pressure tested and evacuated and shipped to site under a vacuum and in this case it is important that none of the unit valves are tampered with as a loss of vacuum may result. 4.6.3.4.1
Site Leak Testing
a)
Absorption Unit Shell
(i)
Isolate the purge unit (manual valve between purge drum and purge pump).
(ii)
Charge a small amount of R-12 (typically 2 kg) into the unit through the access valve on concentrator sump. (Some manufacturers specify R-12 as suitable for leak testing a dry system only and state that it must not be admitted to the system after charging with lithium bromide solution.)
(iii) Raise the gauge pressure within the unit to test figure (typically 0.75 bar) with dry nitrogen. (iv) Check for leaks with halide torch or electronic leak detector. In particular, check all welds, joints, float valves and around hermetic pumps. (v)
Correct or repair any leaks, and retest as necessary.
b)
Purge System
(i)
Ensure gauge unit is isolated.
(ii)
Close the gas ballast valve on the purge pump.
(iii) Connect vacuum hose to the purge pump exhaust fitting, place open end of hose in glass container of water and start the pump. (iv) Purge system is leak free if no bubbles appear in water after about 10 minutes operation. Pay attention to the power supply interruption, otherwise water may be sucked into the system. (v)
If the result is satisfactory, slightly open the gas ballast valve until bubbles appear in water.
(vi) Remove test equipment. Purge system is now ready for service. BSBTC-01
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4.6.3.4.2
Evacuation
This will be carried out by specialists. 4.6.3.4.3
Associated Air Systems
Check in accordance with para. 4.6.3.2.3 4.6.3.4.4
Charging
This will be carried out by specialists. 4.6.3.4.5 a)
Setting to Work and Adjusting Procedures After satisfactory completion of 4.6.3.1. and 4.6.3.4. to 4.6.3.4.iv, operating the absorption machine further visual check should be complete system.
procedures in para. 4.6.3.4.4 and before for the first time, a carried out on the
The chilled water and condenser water systems must have been thoroughly checked in accordance with para. 4.5.1 and 4.6.1 and be ready for operation. The heating fluid (steam or hot water) circuit must have been similarly checked and be ready for operation. b)
System Checks With absorption machine solution pumps electrically isolated, or with their power fuses withdrawn, check that chilled water pumps, condenser water pumps and cooling tower fans operate in the sequence required, rotate in the proper direction, and that flow rates and pressures are set to the required levels. Ensure that solution pumps will be “locked-out” if other equipment essential to their operation stops for any reason. Set each control and safety device in accordance with manufacturer’s instructions or ensure that factory settings are correct and have not been disturbed. The complete control system should be checked out generally in accordance with para. 4.6.4. Check the settings and the functional operation (by raising and lowering the temperature of water at sensing element if necessary) of the following items as appropriate to the system under consideration:
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70
(i)
Load controller, usually chilled water thermostat.
(ii)
Operation of automatic control valve on heating medium. Ensure medium is at the desired temperature and pressure.
c)
Pneumatic/electric switches (on pneumatic systems) and set in accordance with manufacturer’s instructions.
(i)
High temperature control, where fitted. (Typically factory set to cut out at 24oC and cut-in at 18oC refrigerant water temperature.)
(ii)
Time delay relay for high temperature control.
(iii) Note: This is typically set to hold the control incorporative for the first five minutes of machine operation which permits the machine to start when the refrigerant water is initially above the control setting. (iv) Low temperature control. (Typically factory set to cutout at 2oC and cut-in at 6oC refrigerant water temperature.) (v)
Chilled water flow switch (where fitted).
(vi) Condenser water flow switch (where fitted). (vii) Cooling tower thermostat. Ensure raising and lowering of set point starts and stops tower fans. (viii) Condensing water thermostat. (ix) Operation of condensing water control valve. (x)
Setting of motor temperature control protectors. Some types of machine require refrigerant water for lubrication of refrigerant and solution pumps. On these machines the refrigerant sump is dry at start-up and must be filled with distilled water in accordance with the manufacturer’s instructions. Air must not be allowed to enter the system.
(xi) Check operation of float switch controlling minimum operating level of refrigerant (after filling of sump where applicable).
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d)
Start-Up
(i)
Ensure all electrical switches and starters are n ‘off’ 71
position and supplies are isolated. Replace any fuses removed during para. 4.6.3.4.5.b. (ii)
Place chilled water pump, condenser water pump and cooling tower fan starters in ‘auto’ position and close isolators.
(iii) Ensure all water valves are in proper position. (iv) Open the heating fluid isolating valve. (v)
Start the chilled water and condenser water pumps, and cooling tower fans.
(vi) Start the absorption refrigeration machine and place solution pumps in operation (i.e. evaporator, concentrator and absorber pumps). Note : The system not should be operative. The manufacturer’s engineer will not normally make final system adjustments, including placing the absorbent regulating valves in the correct position and sealing to prevent readjustment by unauthorized personnel. e)
Shut-Down The sequence of operation of the ‘dilution’ or shut-down cycle (which prevents crystallization when the solution cools to ambient temperature) must be checked. This dilution sycle normally allows the unit pumps to operate under the control of a time delay relay.
(i)
Stop the absorption refrigeration machine. The condenser pumps and the cooling tower fans should stop immediately and the heating control valve should close.
(ii)
Check that the time delay relay permits the chilled water pumps and the solution pumps to continue operation for the period of time specified by the manufacturer (typically about seven minutes).
f)
Running-In With purge unit operational allow the system to operate for approximately eight hours and at the same time observe the performance and make any necessary adjustments. Ensure purge unit operates satisfactorily. (Purge unit may be of vacuum pump type operated by manual on/off switch, or of the automatic hermetic type which functions continuously while the absorption machine is running.)
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72
After approximately eight hours, stop the unit, then isolate, clean and replace strainers. Return isolating valves to normal position. If unit operation is satisfactory, arrange for final insulation of those parts normally left incomplete until system has been commissioned (e.g. chilled water boxes and where applicable refrigerant sump, piping and motor coating/lubricant lines). 4.6.3.5
Screw Compressor System
The procedure described is for a factory assembled screw compressor water chiller, which has been pressure and leak test, evacuated and dehydrated at the manufacturer’s works, and transported to site as a complete assembly, with operating chargers of refrigerant and lubricating oil. Commissioning should be carried out in accordance with the manufacturer’s instructions. a)
Check :
(i)
that the unit refrigerant and oil charges are intact. If unsatisfactory, arrange for checks and repair leaks; pressure test, dehydrate and recharge by the manufacturer.
(ii)
that the unit manufacturer’s specification.
is installed in recommendations
accordance with and designer’s
(iii) that the unit is correctly levelled. (iv) that vibration isolators (where specified) are provided in accordance with designer’s instructions. (v)
that the unit is free of water and oil leaks.
(vi) that expansion valve bulbs, and any other temperature or pressure sensing bulbs are correctly located with capillary tubes free from damage or distortion. (vii) that pipeline tappings (with fixed or test gauges) for pressure and temperature measurements are available on chilled water and condenser water circuits. b)
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by competent person that the electric control wiring (and pneumatic control systems where specified) is completed and in accordance with para. 4.6.4. In particular : 73
(i)
Set remote overload trips for compressor and oil pump motor (typically 110 to 115 per cent full load current).
(ii)
Set current load limiting device (where provided) to allow operation at 100 per cent load without tripping (typical setting within range 100 to 109 per cent).
(iii) Set any starter time delays, as with start-delta starters. Note :The procedures in the following para. 4.6.3.5.1, 4.6.3.5.2, 4.6.3.5.4 should be adopted when the initial check on unit refrigerant and oil factory charges has indicated loss of pressure during transit from the factory and/or damage to unit. 4.6.3.5.1
Pressure and Leak Testing
Pressure and leak testing should be carried out on completion of the installation, before the unit and the immediately adjacent pipework connections are insulated, and before the condenser or evaporator is finally filled with water. A cylinder of dry nitrogen and a small amount of refrigerant of a type recommended by the unit manufacturer should be used to pressure test the system. Refrigerant R-22 is commonly used for this purpose and also serves as a tracer for leak detection purpose.
BSBTC-01
a)
Charge a small amount of refrigerant into the low side of the system, using convenient valve to achieve a gauge pressure of about 2.0 bar. (It is essential to use low side charging where compressor discharge line is fitted with check valve.)
b)
Close the charging valve and remove the charging apparatus.
c)
Carry out preliminary leak test using halide torch or electronic leak detector.
d)
Connect a cylinder of dry nitrogen to the charging valve and charge to the desired test gauge pressure (typically 15 bar for R-22).
e)
Close the charging valve and remove the charging apparatus.
f)
Thoroughly re-check the entire system for leaks.
g)
Repair any leaks and retest the system. Leaks must not be repaired while the system is under pressure. 74
h)
When the system is found to be leak-free, allow to stand for a minimum of 24 hours under pressure. If no pressure drop occurs (allowing for effects due to changes in ambient temperature) the system is ready for evacuation.
i)
Depressurize the system to atmospheric pressure (where discharge check valve is fitted, the high side after the check valve must be separately depressurized).
4.6.3.5.2. Evacuation and Dehydration This will be carried out by specialists. 4.6.3.5.3. Associated Air Systems Check in accordance with para. 4.6.3.2.3. 4.6.3.5.4. Charging (R-22 System) This will be carried out by specialists. 4.6.3.5.5. Setting to Work and Adjusting a)
Procedure After satisfactory completion of procedures in para. 4.6.3.1. and 4.6.3.5.1 to 4.6.3.5.4, and before operating the compressor continuously for the first time, a further visual check should be carried out on the complete system.
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b)
System Checks
(i)
With compressor motor power circuit electrically isolated, set all refrigeration controls in accordance with design engineer’s instructions, or ensure that factory settings are correct and have not been disturbed. All safety controls should be put through their complete cycle of operation.
(ii)
The number of controls and adjustments are more complex than is usual with reciprocating machines. As a guide, typical controls are listed below. Control settings should be in accordance with the design specification; safety settings should be based on manufacturers’ recommendations.
-
Pressure switches High pressure cut-out Low pressure pump down Low pressure cut-out Low pressure unload 75
-
High pressure oil cut-out Oil failure switch
-
Temperature switches Freeze-up Low water temperature Oil sump temperature heater control Low oil sump temperature heater control
-
Timing relays Oil failure relay Oil pump coast-down relay Compressor loading time delay Oil circulating time delay Anti-recycling relay Flow switches Set to cut-in and cut-out at flow rates recommended by design engineer. Set temperature/load controller in accordance with designer’s brief and para. 4.6.4. (preliminary settings only).
-
-
-
Other adjustments Certain types and sizes of screw machine may have adjustments relating to hydraulic unloader cams, which should be set by manufacturer’s representative. The hydraulic unloader level time should be set by manufacturer’s representative. This includes :Fast unload maximum to minimum load Minimum load to maximum load Maximum load to minimum load
(iii) With compressor power circuit energized check : -
the oil pump for correct rotation.
-
the compressor for correct rotation (momentary start). Do not let the compressor attained the full running speed, since if running backwards, high speed operation may cause damage.
-
These checks should be carried out strictly in accordance with manufacturer’s recommendations.
c)
Start-Up Manual sequence
(i)
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Switch on heater in oil sump and wait until recommended oil temperature (typically 43oC) is attained. 76
Note :Manufacturer may recommended warm-up period of 24 hours with compressor power circuit isolated. (ii)
Energize compressor control circuits.
(iii) Start those items of equipment required to operate by sequence interlock before compressor is started, e.g. evaporator fans, chilled water and condenser water pumps, cooling tower fans, etc. Ensure compressor will be “lock-out” if items essential to its operation stop for any reason. Check all safety controls and reset. (iv) Restore power to compressor power circuits, and start the compressor in accordance with manufacturer’s instructions, ensuring oil pump operative, compressor unloading slide valve moves to fully unloaded position, and other items working correctly by observation of pilot lights. If oil pressure does not reach the required pressure the system will automatically shut down (in approximately five seconds). Controls must be reset and/or fault rectified before proceeding. (v)
With oil pump operative and correct pressure available, the compressor will start fully unloaded after the oil circulating time delay. Check for satisfactory operation of all pilot lights. Ensure items such as hot gas injection solenoid valve (when fitted), small (or single) expansion valve and side oil injection solenoids are operating correctly.
(vi) On completion of warm-up cycle (two minutes loading time delay) check that the main oil injection solenoid valve and the temperature/load controller are activated, and fast unload solenoid valve is de-energized. (vii) Check the compressor loads as required and pilot light operative when loading. On units with dual expansion valves, ensure that the large expansion valve operates as loading passes 33 per cent. Check and adjust superheat settings to design requirements (typically within range 10 to 14oC). (viii) Check the oil gauge pressure and level at 100 per cent capacity (typical 2.0 bar with level to bottom of upper sight glass in sump). (ix) Set the temperature/load controller in accordance with designer’s brief (final settings). BSBTC-01
77
d)
Shut-Down Automatic Sequence
(i)
Check that the large expansion valve (if provided) closes at approximately 26 per cent capacity (may be activated by cam switch in relation to unloader slide valve travel).
(ii)
When the temperature of chilled water reaches the setting of low temperature switch check that shut-down (which normally takes place below 10 per cent load) occurs as follows : Small expansion valve (if provided) is de-energized. Compressor shuts down at required suction pressure (typically a gauge pressure of 5.4 bar). Main and side oil injection valves are de-energized. Temperature/load controller is locked out and all appropriate pilot lights go out.
(iii) Oil re-circulating pump stops after 10 seconds (held in by oil pump coast down relay) to complete automatic shutdown. (iv) Ensure that the anti-recycle relay prevents compressor from restarting until preset time (15 minutes minimum) after low water temperature switch cuts back in. e)
Running-In Note: These checks are carried out after approximately 1000 hours of operation.
(i)
Change the refrigerant filter dryer(s) if moisture shows “wet” or if the desired pressure differential exceeded (typically a gauge pressure of 0.27 bar).
(ii)
Take oil sample and submit to compressor manufacturer for analysis.
(iii) Check cam settings, superheat temperature, unloader speed. 4.6.3.6
and
sub-cooling
Cooling Tower
Field testing cooling towers is a demanding and difficult task. However, certain general criteria that set up the ground rules for proper testing & commissioning of cooling towers are as described below. BSBTC-01
78
4.6.3.6.1
Conditions for Testing & Commissioning
There are certain conditions that require to be fulfilled before T & C can commence. Ensure that a)
the water system serving the tower has been thoroughly cleaned, preliminary checks and setting to work and balancing have been carried out in accordance with para. 4.5.1 and 4.6.1;
b)
the fan serving the cooling tower has been set to work in accordance with para. 4.5.2 and 4.6.2 noting any permanent obstruction and removing all foreign obstructions;
c)
the interior fills of the tower are properly cleaned and free from foreign materials such as scale, algae or fur;
d)
the water level in the tower basin is maintained at the proper level, making sure by visual check of the basin sump that the centrifugal action during full flow does not cause any entrainment of air which may cause pump cavitation;
e)
all valves except balancing valves in the water system are in full open position;
f)
provisions for facilities to determine make-up and blowdown water flow rates are available, if not valve off both.
4.6.3.6.2
Test Method
The actual test method consists of the following steps :(i)
Determine volume of water in the tower, volume of make-up water and volume of blowdown water.
(ii)
Record temperature of make-up water.
(iii) Measure the volume and temperature of make-up water at the point of entry to the system. (iv) Measure the volume and temperature of blowdown water at the point of discharge from system. (v)
Measure inlet and outlet dry and wet bulb temperatures.
(vi) Use entering & leaving wet bulb temperatures to determine the tower performance against design. BSBTC-01
79
(vii) Use entering and leaving dry and wet bulb temperatures to determine the rate of evaporation involved. (viii) Measure wet and dry bulb temperatures between 1 and 1.5 metre from the tower on all sides. These readings should be taken half-way between the base and the top of the inlet louvre at not more than 1.5 metre spacing horizontally and averaged out. (ix) Note any unusual inlet conditions, wind velocity and wind direction at the time of test. (x)
Take readings continually with a minimum of time lapse between readings.
(xi) If the first test indicates a tower deficiency, perform two additional tests to verify the original readings. 4.6.4 Control Systems 4.6.4.1
General
The testing and commissioning of Central Control and Monitoring System (CCMS) and Building Automation System (BAS) will be carried out by specialists and are not covered by these guidelines. Control systems as defined herein relate to ‘on the plant’ control systems, including pressure/temperature sensing points, motorized valves, dampers, etc. with which the CCMS/BAS may interface. It is essential that all wirings within the control panel have been checked for loose connections, correct terminations and compliance with wiring diagrams. In addition it is also assured that functional checks to ensure that all interlocking and sequencing have been carried out in accordance with the requirements and specifications. It is also critical that the procedures described elsewhere relating to the regulation of air, water, refrigeration systems and any other connected equipment have been carried out prior to commissioning the control system. 4.6.4.1.1. Preliminary Checks This section is common to all types of system. Before attempting to set up automatic controls it should be ascertained that the following requirements are satisfied :
BSBTC-01
(i)
All electrical supplies are isolated.
(ii)
All control components are installed in accordance with specified requirements and manufacturers’ instructions, 80
e.g., that control valves are correctly positioned and ported and that temperature and humidity elements suit the temperature ranges involved. (iii) ALL SAFETY DEVICES INCLUDING CIRCUIT INTERLOCKS AND CUT-OUTS ARE CORRECTLY INSERTED INTO THE OVER-ALL OPERATIONAL PLAN AND WILL EFFECTIVELY CARRY OUT THE PURPOSE INTENDED. (iv) All sensing elements are located in a position which will give good representation of the controlled variable and are not subject to extraneous influence. (v)
Measuring instruments have been calibrated against certified standards.
4.6.4.1.2. Operating Checks Checks : (i)
that a full rated flow of the controlled media, the pump and fan pressures are within design tolerances immediately prior to setting-up;
(ii)
that the input temperature of the controlled media and the pressure at the input of the controlled device at full design flow condition are each within specified design limits and that the pressure difference across the device is to design requirements. Note: In the case of variable fluid flow the pressure available at any particular controlled device will tend to vary in relation to demands at other points of regulation within the system. There will also be some variation of the temperature of fluid available at the inlet of the device particularly at low-flow conditions. Hence, checks must be made to ensure that at any point in the system the fluid to be controlled is not only available within the specified limits of temperature and pressure but that the controlled device continues to provide the degree of control required throughout the range of variations in flow and pressure to which the system may be subjected.
(iii) that the movement of the controlled device matches with the travel of the actuator. For example, examine damperactuator assemblies. 4.6.4.1.3. Electricity Supply and Wiring BSBTC-01
81
The following checks are to be made before switching on the electricity supply : (i)
that the wiring has been installed to the required standard regulations and is in accordance with the control equipment manufacturers’ requirements. Special care should be taken to ensure that the cable possesses suitable physical and electrical characteristics and that the earthing suits the equipment;
(ii)
that all connections are in accordance with the relevant wiring diagrams supplied;
(iii) that the electrical supply at the point of distribution for the control system is correct and that suitably rated fuses are available. 4.6.4.1.4. Connection to electrical Supply Switch on the electrical supply. 4.6.4.2
Pneumatic Control System
4.6.4.2.1. Check-Out, Calibration and Setting-Up Procedure The procedure divides the system into principal component parts as follows : (i)
Compressed air supply.
(ii)
Valve, damper and other actuators.
(iii)
Controllers.
4.6.4.2.2
Compressed Air Supply
Note: It is assumed firstly that air leakage checks have been made progressively during the construction period in accordance with the specified requirements. It is further assumed that air compressing equipment has been subjected to mechanical and electrical checks in accordance with the manufacturers’ instructions. Check where applicable : The pipework and connections have been installed in accordance with relevant control system drawings. a)
BSBTC-01
the compressed air receiver(s) relief valve(s) is/are correctly set and operating. After cooler to be checked if fitted. 82
b)
The action of the pressure switch initiating a compressor start is correct and that the compressor(s) subsequently effectively recharge the system.
c)
The duty-changeover system for the compressors is functioning correctly.
d)
The air receiver is at the required pressure. certificate to be provided before operation.
e)
The air drying apparatus is properly installed, prepared and operative.
Survey
This may involve one or more of the following supplementary checks : (i)
that the electrical supply is available to any refrigeration equipment specifically intended for dehumidification of the control air supply and that this equipment is functioning correctly;
(ii)
that the compressed air delivered is below the specified dew point temperature required at any point in the system;
(iii) that any chemical dryer is ready to accept air through at least one cell; (iv) that where cooling water is used it is available, flowing at the required rate and at an acceptable temperature. f)
Visually, at the nearest convenient pressure reducing set, for residual cleanliness and freedom from oil and water in the delivered air.
4.6.4.2.3. Valve, Damper and Other Actuators Check that the actuator provides the correct position of the controlled device with zero pressure input. 4.6.4.2.4
BSBTC-01
Setting-Up Action
a)
Install a suitable test pressure gauge in the branch line output from the controller, near to the actuator(s).
b)
Check the operating range adjustment where fitted.
c)
Check the ‘start point’ adjustment where fitted.
d)
Vary the line air pressure to the actuator and check that the pressure at which the actuator starts to move corresponds with the desired ‘start point’ pressure. 83
e)
Vary the line air pressure until the actuator has moved the device through the required travel and check that the air pressure change is in accordance with the control sequence. Note: Throughout this procedure check for smooth and regular movement of the actuator and device. In the case of valve control, this calls for attention to gland packings and in the case of dampers that they do not bind at the bearings or are otherwise mechanically unsound. (See Checks in para. 4.5.2.2).
4.6.4.2.5
Transmitters/Controllers
a)
Transmitters, where installed, should be checked for correct output and/or calibrated as necessary in accordance with the manufacturers’ instructions.
b)
Check that the action of the controller is correct for the application (direct or reverse-acting).
c)
Set the throttling range or proportional band of the controller to the design value. For two and three term controllers, these settings should suit the characteristics of the plant. In the case of controllers which are to be reset by other source pressures, ensure that the reset input pressure and setting is correct for the calibration procedure for that particular instrument.
d)
Ensure that a suitable test pressure gauge is installed in the branch line output from the controller.
e)
Move the set-point of the controller so that it is equivalent to the condition measured at the detector. It may be necessary to stablize conditions at the detector during this procedure.
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f)
Calibrate the instrument so that a gauge pressure equal to the ‘start point’ gauge pressure plus half the operating range is note on the test gauge. (For example : range 20 to 100 kPa (0.2 to 1.0 bar), set at 60 kPa (0.6 bar)). Manufacturers may sometimes recommend slight variations on this.
g)
With proportional controllers, incremental movements of the set-point should give proportional movement of the final control device in the required direction. Check that the total movement of the set-point to give full movement of the control device corresponds to the proportional band setting. 84
h)
Check the operation of any pressure switches and pneumatic relays which may form part of the control systems, etc., by applying a suitably varied control pressure. Adjust the set-point to the specified desired value.
i)
Cancel any measures that may have been taken to stabilize the conditions at the detector thus returning the plant ready for normal working. Adjust the throttling range of controllers to obtain the minimum proportional band consistent with stable control.
j)
Any interlocking, travel limit or overriding devices should then be checked to ensure that the overall sequence of control is achieved.
4.6.4.2.6. Plant Operation Following the T & C procedures, the design conditions should be achieved and maintained for a suitable period of observation. If the conditions cannot be achieved or maintained, then a check on the final control devices should be carried out to ascertain that maximum correction has been applied. If this is satisfied an investigation beyond the control system is indicated. 4.6.4.3
Electrical and Electronic Control Systems
4.6.4.3.1
Check-Out, Calibration and Setting-Up Procedure
The procedure divides the system into principal component parts as follows : (i)
Valve, damper and other actuators
(ii)
Controllers and detectors
4.6.4.3.2
Actuating Units
Check : (i)
that the actuator has the correct movement so that it will give the required travel of the final control device;
(ii)
that any linkage adjustments for rotation lift or close-off have been suitably set;
(iii) that in the case of spring return motors being fitted, the position assumed upon interruption of the power supply is correct; BSBTC-01
85
(iv) that all action intended to succeed an interruption of power, and the subsequent reinstatement, are faithfully followed; (v)
that throughout this procedure there is smooth and regular movement of the actuating motor and regulator. Note: In the case of valve control, this calls for attention to gland packings and in the case of dampers that they do not bind at the bearings or are otherwise mechanically unsound. (See Mechanical Checks in para. 4.5.1.4).
4.6.4.3.3
Transmitters
Calibrate as follows : (i)
Move the set-point of the controller so that it is equivalent to the condition measured at the detector. It may be necessary to stabilize the conditions at the detector during this procedure.
(ii)
Set the proportional band of the controller to the design value. For two and three term controllers, these settings should suit the characteristics of the plant. In the case of controllers which are to be reset by other source signals arrange for second, or other stage, signal inputs shall be connected in accordance with the calibration procedure for that particular instrument. For example, adjust “Authority” settings as required and where applicable.
(iii) With proportional controllers, incremental movements of the set-point should give proportional movement of the final control device in the required direction. Check that the total movement of the set-point to give full movement of the control device corresponds to the proportional band setting. (iv) In the case of the two-position control check that the switching action is correct and any internal heaters are disconnected during calibration. (v)
Adjust the set-point to the specified desired value.
(vi) Make ‘Dead Zone’ adjustment where applicable. (vii) Cancel any measures that may have been taken to stabilize the conditions at the detector thus returning the plant ready for normal working. BSBTC-01
86
(viii) Adjust proportional bands of controllers to attain the minimum deviation consistent with stable control. In the case of timed-two-position and floating control systems, set the design differential and where applicable, the time interval which is consistent with stable control and the minimum deviation. 4.6.4.3.4. Sequence Control Any interlocking or overriding devices should then be checked to ensure that the overall sequence of control is achieved. 4.6.4.3.5. Plant Operation Following the T & C procedures, the design conditions should be achieved and maintained for a suitable period of observation. If the conditions cannot be achieved or maintained, then a check on the final control devices should be carried out to ascertain that maximum correction has been applied. If this is satisfied an investigation beyond the control system is indicated. 4.6.5. Performance Tests After the system has been commissioned, its performance shall be observed and checked under normal conditions, both winter and summer while making all required adjustments to automatic controls, air dampers, registers, fans etc. until all performance requirements are met. 4.6.6 Noise and Sound Tests
BSBTC-01
4.6.6.1
The present state of the art does not permit tests to determine if equipment is operating with desired sound levels. Field tests can determine only sound pressure levels, and equipment ratings are almost always in terms of sound power levels. Until new techniques are developed, the commissioning engineer can determine only if sound pressure levels are within desired limits and, if not, determine which equipment, systems or components are the source of excessive or disturbing transmission.
4.6.6.2
When carrying out the testing and commissioning procedure, one should make reference to the Technical Memorandum for the assessment of noise issued by the Environmental Protection Department for the determination of the accceptable noise level; such as the “Area Sensitivity Ratings”(ASRs) and Acceptable Noise Levels(ANLs). In determining allowable HVAC equipment noise, “A-weighted” sound levels, dBA, are 87
used when carrying out all field tests as “A-weighting of the sound level meter is becoming the standard measurement relating to the probable subjective assessment of the loudness level of sound of any frequency or intensity.
BSBTC-01
4.6.6.3
Most field sound measuring instruments and techniques yield an accuracy of ±2 dB, which is about the smallest difference in sound pressure level that the average person can discern. A reasonable tolerance for sound criteria is 5 dB, and, if 35 dB(A) were to be considered as the maximum allowable noise, the design engineer should realistically specify 30 dB(A).
4.6.6.4
The measured sound level of any location is a combination of all sound sources present including sound generated by HVAC equipment as well as sound from other sources such as plumbing systems and fixtures, elevators, light ballasts and outside noises. In testing HVAC systems for sound, all sources of sound from other than HVAC equipment are considered as background or ambient noise.
4.6.6.5
Background sound measurements generally have to be made when : (1) specification requires determination of sound levels from HVAC equipment only as opposed to the sound level in a space not exceeding certain specified level, (2) sound level in the space exceeds desirable level, in which case it is necessary to determine what part of the noise is contributed by the HVAC system and (3) for residential locations and spaces where there is little significant background noise during the evening hours and where generally low allowable noise levels are specified or desired.
4.6.6.6
Ideally, the building should be completed and ready for occupancy before sound level tests are taken. All spaces in which readings will be taken should be furnished with drapes, carpeting and furniture, as these affect the room absorption and the subjective quality of the sound. In actual practice, since most tests have to be conducted before the space is completely finished and furnished for final occupancy, the commissioning engineer must make some allowances. Since furnishings increase the absorption coefficient and reduce sound pressure level by around 4 dB, the following guidelines should suffice for measurements made in unfurnished spaces. If sound pressure level is 5 dB or more greater than specified or desired criterion, it can be assumed that criterion will not be met even with the increased absorption provided by furnishings. If sound pressure level of 0-4 dB greater than specified or desired criterion, recheck when the 88
room is furnished to determine compliance. 4.6.6.7
Follow this general procedure :
a)
Obtain a complete set of accurate, as-built drawings and specifications, including duct and piping details. Review specifications to determine sound and vibration criteria and any special instructions for testing.
b)
Visually check the system for noncompliance with plans and specifications, obvious errors and poor workmanship. Turn the system on for audible check. Listen for noise and vibration, especially duct leads and loose fittings that can be the source of disturbing noise.
c)
Adjust and balance equipment as described in other sections of this procedure so final acoustical tests are made with the system as it will actually be operating. It is desirable to perform acoustical tests for both summer and winter operation, but where this is not practical, make tests for the summer operating mode as it usually has the potential for higher sound levels. Test must be made for all mechanical equipment and systems including standby. (For equipment or systems that can function concurrently but cannot be so operated at the time of tests, separate sound measurements must be taken and added in accordance with Table 2 to determine compliance with desired criteria.)
d)
Check calibration of instruments.
e)
Measure sound levels in all areas as required, combining measurements as indicated in item c) above if equipment or systems must be operated separately. Before final measurements are made in any particular area, survey the area using an A-weighted scale reading dB(A) to determine the location of the highest sound pressure level. Indicate this location on a testing form and use it for test measurements. Restrict the preliminary survey to determine location of test measurements to areas that can be occupied by standing or sitting personnel. For example, measurements would not be made directly in front of a diffuser located in the ceiling, but they would be made as close to the diffuser as standing or sitting personnel might be situated. In the absence of specified sound criteria, the commissioning engineer shall measure sound pressure levels in all occupied spaces to determine any sources of excessive or disturbing noise.
f) BSBTC-01
Determine if background noise measurements must be made. 89
(i)
If specification requires determination of sound pressure level from HVAC equipment only, it will be necessary to take background noise readings to determine the background correction factor as indicated in Table 1.
(ii)
If specification requires compliance with a specific noise level or criteria (for example : sound pressure levels in office areas shall not exceed 43 dB(A)), ambient noise measurements are needed to be made only if the noise level in any area exceeds the specified value. Use Table 1 to determine that portion of noise contributed by HVAC system.
(iii) For residential locations and areas requiring very low noise levels such as sound recording studios and locations that will be used during the normally quieter evening hours, it is usually desirable to make sound measurements in the evening and/or take ambient noise measurements. As shown in Tables 1 and 2, if two sound pressure levels are 10 dB or more apart, the lower sound level has no significant effect on the overall or combined sound level. But if they are 3 dB or less apart there is a very significant interaction. If the background noise is only 3 dBA lower than the combined noise, then the background noise is equal to the noise as generated by HVAC equipment. Table 1 - Background Correction (dB) Decibel difference between sound level when air conditioning equipment is operating (total level) and when it is not operating (background level) Decibel to be subtracted from total sound level in order to get the sound level due to airconditioning equipment alone
BSBTC-01
90
0
1
2
3
4
7
10
over 10
7
4
3
2
1
0.5
Table 2 –Summation of Noise Levels Difference in dB(A) between two noise levels being summed
Amount in dB(A) to add to the higher noise level
0 to 0.5 1.0 to 1.5 2.0to 3.0 3.5 to 4.5 5.0 to 7.0 7.5 to 12 more than 12.0
3.0 2.5 2.0 1.5 1.0 0.5 0
Note:
When using Table 2 noise levels should be summed in a pairwise fashion and the final total rounded to the nearest whole dB(A), with values of 0.5 or more being rounded upwards.
4.6.7 Vibration Tests
BSBTC-01
4.6.7.1
Testing for vibration is necessary to assure that (1) equipment is operating with satisfactory vibration levels and (2) objectionable vibration and noise are not transmitted to the building structure. Although these two factors are inter-related, they are not necessarily interdependent. A different solution is required for each, and it is essential to test both the isolation system and the vibration levels of the equipment.
4.6.7.2
the general order of steps in vibration testing are as follows :
a)
Make a visual check of all equipment for obvious errors that must be corrected immediately.
b)
Make sure all isolation systems are free floating and not short circuited by any obstruction between equipment to equipment base and building structure.
c)
Turn on the system for audible check for any obviously rough operation. Check bearing with stethoscope. Bearing check is especially important because bearings can become defective in transit and/or if equipment was not properly stored and maintained. Defective bearings should be replaced immediately to avoid damage to shaft and other components.
d)
Equipment and systems should be adjusted and balanced as described in other sections of this procedure so final vibration tests are made on equipment as it will actually be operating.
e)
Test equipment vibration. 91
4.6.7.3
BSBTC-01
The following steps should be taken to assure that vibration isolation systems are functioning properly :
a)
Assure that system is free floating by applying unbalanced load, which should cause system to move freely and easily. On floor mounted equipment, check that there are no obstructions between base or foundation and building structure that would case transmission while still permitting equipment to rock relatively free because of the application of unbalance force. On suspended equipment check that hanger rods are not touching the vibrating plant. Rigid connections such as pipes and ducts can prohibit mounts from functioning properly by providing a flanking path for transfer of vibration to the structure, etc. Note the fact that the system is free floating does not mean that the isolators are functioning properly. For example, a 500 rpm fan installed on isolators having a natural frequency of 500 rpm could be free floating but would actually be in resonance, resulting in transmission to the building and excessive movement.
b)
Determine if isolators are properly adjusted and providing desired isolation efficiency. All isolators supporting a piece of equipment should have approximately the same deflection, i.e. compressed the same under the weight of equipment. If not, they have been improperly adjusted, installed or selected; this should be corrected immediately. The only accurate check of isolation efficiency is to compare vibration measurements of equipment operating with isolators to measurements of equipment operating without isolators. As such tests are usually impractical, it is best to check isolator deflection to determine if deflection is as specified, and if specified or desired isolation efficiency is being provided.
4.6.7.4
While it is easy to determine the deflection of spring mounts by measuring with a ruler the difference between the free heights (information as shown on submittal drawings or available from manufacturer), such measurements are at best difficult with most pad or rubber mounts. Furthermore, most pad and rubber mounts do not lend themselves to accurate determination of natural frequency as a function of deflection. For such mounts, the most practical approach is to check that there is no excessive vibration of base and no noticeable or objectionable vibration transmission to the building structure.
4.6.7.5
If isolators are in the 90% efficiency range and there is transmission to the building structure, the equipment is operating very roughly or there is a flanking path of 92
transmission such as connected piping or obstruction under the base. 4.6.7.6
5.
BSBTC-01
It is possible that secondary vibrations transmitted from isolators may coincide with the resonant frequency of the structural floor slab on or from which the equipment is supported or suspended. In such cases, the solution is that the secondary frequency transmitted to the structure must be altered which may be achieved by adjustment of the isolator deflection.
Calibrated Equipment 5.1
The Contractor shall supply calibrated equipment as stipulated in the Specification of the Contract for the inspection, measuring and testing of the installation. The equipment shall be calibrated by laboratories accredited by the Hong Kong Laboratory Accreditation Scheme (HKLAS) or other recognised accredited laboratories..
5.2
A list of equipment proposed to be used for T & C must be available prior to commissioning the work. All equipment that requires periodic calibration shall have this carried out before the work is commenced and data sheets on such test instrument indicating the manufacturer’s name, model number, latest date of calibration and correction factors shall be submitted to the Project BSE for approval. If any item requires re-checking the accuracy because of the time that has elapsed since the previous calibration, this shall be carried out prior to commencing the work.
5.3
The suggested minimum items of instruments & accessories necessary to carry out the objectives are : a)
Inclined manometer calibrated in not less than 0.1 Pa (0.0005 in. of water) divisions.
b)
Combined inclined and vertical manometer 0-2000 Pa (0-10 in. of water) is generally the most useful.
c)
Pitot tubes (usually 450-mm (18-in.) and 1200-mm (48-in.) long tube cover most balancing requirements).
d)
A tachometer, which should be the high quality, direct contact, self-timing type.
e)
Clamp-on ampere meter with voltage scales.
f)
Deflecting vane anemometer.
g)
Rotating vane anemometer.
h)
Thermal-type (hot-wire) anemometer. 93
Note:
BSBTC-01
i)
Dial and glass stem thermometers.
j)
Pressure gauges (Manifold & Single)
k)
Test wells
l)
Pressure tappings
* Delete if not appropriate
94
Appendix A
Testing and Commissioning Certificate on Air-conditioning, Refrigeration, Ventilation and Control Systems Part 1 :
Part 2 :
Details of Project 1.1
Project title (with location) :
1.2
* P.W.P. / Project No. :
1.3
*Contract/sub-contract/Quotation No. :
1.4
* Contractor/Sub-contractor :
1.5
PBSE :
1.6
PBSI :
Declaration 2.1
I certify that the Air-conditioning, Refrigeration, Ventilation and Control Systems as specified in the Contract/Sub-contract/Quotation at the above location has been inspected, tested and commissioned in accordance with this procedure and/or any other procedures agreed between the PBSE and the Contractor. The results are satisfactory in the aspects as mentioned in Part 3 and/or as recorded in Part 4 of this Certificate, except as indicated in the COMMENTS items.
2.2
I also certify that site tests have been performed in accordance with the requirements set out in Appendix A of this procedure and that the results are satisfactory. A record of the tests has been prepared and submitted to the project BSE.
Signature of Contractor‘s Representative Full Name of Contractor‘s Representative Designation of Contractor‘s Representative Name and Stamp of Contractor Date Note :
This certificate must be signed by a person authorized by the Firm/Company. * Delete if not applicable
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 1 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Items tested/ Items witnessed checked by by Contractor PBSE/PBSI
Part 3.
Items Inspected and Tested
3.1
The General Requirements as indicated in the T & C procedure have been complied with.
3.2
Precommissioning Checks
3.2.1
Water Distribution System
a)
*Yes/No/N.A.
*Yes/No/N.A.
The system has been properly cleaned, flushed and filled with water.
*Yes/No/N.A.
*Yes/No/N.A.
b)
The equipment associated with the system has undergone the mechanical and electrical checks and the results are satisfactory.
*Yes/No/N.A.
*Yes/No/N.A.
3.2.2
Air Distribution System
a)
The system has been been properly cleaned and usually checked for air tightness.
*Yes/No
*Yes/No
b)
The equipment associated with the system has undergone mechanical and electrical checks and the results are satisfactory.
*Yes/No
*Yes/No
3.3
Setting to Work & Balancing
3.3.1
Water Distribution System
a)
The water pumps have been commissioned in accordance with this procedure and the pumps are operating satisfactorily.
*Yes/No/N.A.
*Yes/No/N.A.
b)
The water flow rates of the system have been regulated and balanced in accordance with this procedure. The results are satisfactory meeting the specified requirements.
*Yes/No/N.A.
*Yes/No/N.A.
3.3.2
Air Distribution System
a)
The filters have been commissioned according to *this/manufacturer’s procedure and the results are satisfactory, meeting the specified requirements.
*Yes/No/N.A.
*Yes/No/N.A.
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 2 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Items tested/ Items witnessed checked by by Contractor PBSE/PBSI
b)
The fans have been commissioned according to *this/manufacturer’s procedure and the results are satisfactory meeting the specified requirements.
*Yes/No/N.A.
*Yes/No/N.A.
c)
The air flow rates of the system have been regulated in accordance with this procedure and the system is delivering the designed air volumes at the terminal outlets.
*Yes/No/N.A.
*Yes/No/N.A.
3.3.3
Refrigeration Systems
a)
The system has been satisfactorily cleaned and the equipment has undergone electrical and mechanical checks.
*Yes/No
*Yes/No
b)
Reciprocating Compressor System
(i)
The refrigeration system has been commissioned by a specialist in accordance with the manufacturer’s recommendations.
*Yes/No/N.A.
*Yes/No/N.A.
(ii)
The refrigeration system has satisfactorily completed the running-in period as specified in this procedure and all necessary adjustments/ repairs/ replacements have been carried out.
*Yes/No/N.A.
*Yes/No/N.A.
c)
Centrifugal Compressor System
(i)
The refrigeration system has been commissioned by a specialist in accordance with the manufacturer’s recommendations.
*Yes/No/N.A.
*Yes/No/N.A.
(ii)
The refrigeration system has satisfactorily completed the running-in period as specified in this procedure and all necessary adjustments/ repairs/ replacements have been carried out. Absorption System
*Yes/No/N.A.
*Yes/No/N.A.
(i)
The refrigeration system has been commissioned by a specialist in accordance with the manufacturer’s recommendations.
*Yes/No/N.A.
*Yes/No/N.A.
(ii)
The refrigeration system has satisfactorily completed the running-in period as specified in this procedure and all necessary adjustments/ repairs/ replacements have been carried out.
*Yes/No/N.A.
*Yes/No/N.A.
(d)
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 3 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Items tested/ Items witnessed checked by by Contractor PBSE/PBSI
(e)
Screw Compressor System
(i)
The refrigeration system has been commissioned by a specialist in accordance with the manufacturer’s recommendations.
*Yes/No/N.A.
*Yes/No/N.A.
(ii)
The refrigeration system has satisfactorily completed the run-in period as specified in this procedure and all necessary adjustments/ repairs/ replacements have been carried out.
*Yes/No/N.A.
*Yes/No/N.A.
(f)
Cooling Tower *Yes/No/N.A.
*Yes/No/N.A.
The cooling tower(s) of the installation *has/have been field tested in accordance with this procedure and the results are satisfactory, meeting the specified requirements. 3.3.4
Control System
(a)
All the safety devices including circuit interlocks and cut-outs have been checked for correct installation and operation.
*Yes/No
*Yes/No
(b)
The complete pneumatic and/or electric control system *has/have been checked and commissioned in accordance with this procedure.
*Yes/No
*Yes/No
3.3.5
Noise and Sound Tests *Yes/No/N.A.
*Yes/No/N.A.
*Yes/No/N.A.
*Yes/No/N.A.
The noise and sound levels in areas as specified have been checked in accordance with this procedure and are found in compliance with the Specification. 3.3.6
Vibration Tests The vibration tests for equipment as specified have been carried out in accordance with this procedure and the results are satisfactory, meeting the specified requirements.
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 4 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Items tested/ Items witnessed checked by by Contractor PBSE/PBSI
3.3.7
Performance Test
(i)
A full-load performance test has been carried out and the results which were recorded separately were found meeting the specified requirements.
*Yes/No/N.A.
*Yes/No/N.A.
(ii)
a full-load performance test has NOT been carried out but it will be carried out during the free-maintenance period.
*Yes/No/N.A.
*Yes/No/N.A.
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 5 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Items tested/ Items witnessed checked by by Contractor PBSE/PBSI
3.4
Comments
*Yes/No/N.A.
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of BSB Staff)
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 6 of 14
*Yes/No/N.A.
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Part 4 :
Test Record attached to the Test Certificate
4.1
General Plant performance can be substantiated only when the test data have been recorded and validated against the design data. Proforma for recording such data can be found in the succeeding pages and these should be properly filled in before submission to the designers with any relevant comments related to site conditions.
4.2
Packaged Water Chillers Location :
No. :
Design
Test
Machine Type Refrigerant Type Capacity
(kW)
Leaving Chilled Water Temperature
(oC)
Leaving Chilled Water Temperature control Limited
(oC)
Entering Chilled Water Temperature
(oC)
Chilled Water Quantity
(l/s)
Entering Condenser Water Temperature (oC) Leaving Condenser Water Temperature (oC) Condenser Water Quantity
(l/s)
Evaporator Fouling Factor Condenser Fouling Factor Evaporator Working Pressure
(kPa)
Evaporator Test Pressure
(kPa)
Evaporator Entering Temperature
(oC)
Evaporator Leaving Temperature
(oC)
Condenser Working Pressure
(kPa)
Condenser Test Pressure
(kPa)
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 7 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Location : Condenser Entering Temperature
(oC)
Condenser Leaving Temperature
(oC)
No. :
Design
Test
No. :
Design
Test
Motor Type Motor Speed
(rev/s)
Motor Full-load Condition
(amp. & volt)
Motor No-load Condition
(amp. & volt)
Drive Arrangement Machine Mountings Supply Voltage 4.3
(V)
Air-Cooled Condensing Sets Location : Compressor Refrigerant Type Capacity
(kW)
Saturated Suction Temperature
(oC)
Saturated Discharge Temperature
(oC)
Total Heat Rejected
(kW)
Compressor Absorbed Power
(kW)
Motor Nameplate Rating
(kW)
Motor Type Motor Speed
(rev/s)
Drive Motor Full-load Condition
(amp. & volt)
Motor No-load Condition
(amp. & volt)
Supply Voltage
(V)
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 8 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Location :
No. :
Design
Test
No. :
Design
Test
Condenser Capacity
(kW)
Condensing Temperature
(oC)
Summer Design External Dry Bulb
(oC)
Sub-cooling
(oC)
Head Pressure Control Method Fan Type Drive Motor Type Motor Nameplate Rating
(kW)
Motor Speed
(rev/s)
Motor Full-load Condition
(amp. & volt)
Motor No-load Condition
(amp. & volt)
Supply Voltage 4.4
(V)
Cooling Towers Location : Type : Cooling Capacity
(kW)
Summer Design Wet Bulb Temperature (oC) Altitude above Sea Level
(m)
Entering Dry Bulb Temperature
(oC)
Entering Wet Bulb Temperature
(oC)
Leaving Dry Bulb Temperature
(oC)
Leaving Wet Bulb Temperature
(oC)
Make-up water Quantity
(l/s)
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 9 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Location : Constant Bleed Water Quantity
(l/s)
Cooling Water Flow Rate
(l/s)
Cooling Water Entering Temperature
(oC)
Cooling Water Leaving Temperature
(oC)
No. :
Design
Test
No. :
Design
Test
Fan Type Fan Outlet Size
(m2)
Fan Volume
(l/s)
Fan Drive Motor Type Motor Speed
(rev/s)
Motor Rating
(kW)
Tower Water Connections Diameter
(mm)
Balance Pipe Connection Diameter
(mm)
Supply Voltage 4.5
(V)
Pumps ( Medium) Location : Volume Flow Rate
(l/s)
No Flow Head
(kPa)
Full Flow Discharge Head
(kPa)
Full Suction Pressure
(kPa)
Full Flow Differential
(kPa)
Motor Type Motor Speed Motor Full-load Condition
(rev/s) (amp. & volt)
Supply Voltage
(V)
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 10 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A 4.6
Air Handling Units Location :
No. :
Design
Test
Outdoor Air Condition Dry Bulb Temperature
(oC)
Wet Bulb Temperature
(oC)
Time of Day Condition
(Hrs) (Cloudy/Sunny)
Total Air Quantity
(l/s)
Fresh Air Quantity (Minimum)
(l/s)
Fresh Air Quantity (Maximum)
(l/s)
Fan Type Speed
(r/s)
Drive Inlet pressure
(kPa)
Discharge pressure
(kPa)
Fan Static Pressure (Discharge - Inlet)
(kPa)
Supply Voltage
(V)
Filter Type : Inlet Pressure
(kPa)
Outlet Pressure
(kPa)
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 11 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Location :
No. :
Design
Test
(m2)
Effective Area Velocity
(m/s)
Cleanliness Cooling Coil Entering Air Dry Bulb Temperature
(oC)
Entering Air Wet Bulb Temperature
(oC)
Leaving Air Dry Bulb Temperature
(oC)
Leaving Air Wet Bulb Temperature
(oC)
Entering Water Temperature
(oC)
Leaving Water Temperature
(oC)
Entering Water Pressure
(kPa)
Leaving Water Pressure
(kPa)
Water Quantity
(l/s)
Evaporator Suction Pressure
(kPa) (oC)
Evaporator Suction Temperature Evaporator Discharge Pressure
(kPa)
Evaporator Discharge Temperature
(oC)
Effective Area
(m2)
Velocity
(m/s)
Heating Coil (Medium) Entering Air Dry Bulb Temperature
(oC)
Leaving Air Dry Bulb Temperature
(oC)
Effective Area
(m2)
Velocity
(m/s)
Entering Water Temperature
(oC)
Leaving Water Temperature
(oC)
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 12 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A Location : Entering Water Pressure
(kPa)
Leaving Water Pressure
(kPa)
Water Quantity
No. :
Design
Test
No. :
Design
Test
(l/s)
No. of steps Capacity of Each Steps
(kW)
Air Quantity 4.7
(l/s)
Heating Coils (Not included in Air Handling Unit) Location : Medium Entering Air Dry Bulb Temperature
(oC)
Leaving Air Dry Bulb Temperature
(oC)
Effective Area
(m2)
Velocity Air Quantity
(m/s) (l/s)
Entering Water Pressure
(kPa)
Leaving Water Pressure
(kPa)
Water Quantity
(l/s)
Capacity of Coil
(kW)
No. of Steps Capacity of Each Step
4.8
(kW)
Ducts, Grilles, Diffusers etc. Use the air flow sheets and indicate the design and test figures as indicated in Fig. 5 Appendix C.
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 13 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix A 4.9
Testing Equipment
Type
Note:
Model
Serial No. of Instrument
Date of Calibration
* Delete if not applicable
Tested / Checked by (Name of Contractor’s Representative)
Signature
Witnessed by (Name(s) of *PBSE/*PBSI))
Signature(s)
Building Services Branch, ArchSD FORM NO. BS/SR.061 Issue Date: 3 March 2000
Page 14 of 14
Filecode: SR61.doc Revision Date:15 March 2000
Appendix B
Testing and commissioning progress chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Contract No. : Contract Title : Name of Contractor/sub-contractor : Contract Period :
/
/20
to
/
/20
* Revised/Actual Completion Date :
/
/20
Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
1. 1.1
Chillers Cleanliness & State Check 1.1.1 Air System 1.1.2 Water System 1.1.3 Refrig. System
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
Section 4.6.3.1.1 Section 4.6.3.1.2.b Section 4.6.3.1.2.a Section 4.6.3.1.2.c
Submission of Record of Test 1.2
Mechanical Check
1.2.1 Fans
Section 4.6.3.1.3 Section 4.6.3.1.3.a
1.2.2 Pumps 1.2.3 Compressors 1.2.4 Drives
Section 4.6.3.1.3.b Section 4.6.3.1.3c
Submission of Record of Test 1.3
Electrical Check
1.3.1 Electrical Supplies Isolated
Section 4.6.3.1.4. Section 4.6.3.1.4.a
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
Page 1 of 19
Filecode: SR21.Doc KFL/WKY
Appendix B
Testing and commissioning progress chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
1.3.2 Electrical Supplies Available
Reference to Approved T&C Procedure Section 4.6.3.1.4.b
S A S A S A S A S A S A S A S A
Submission of Record of Test 1.4 1.4.1 1.4.2 1.4.3 1.4.4
Test of Recip. Compressor System Pressure & Leakage Test Evacuation & Dehydration Charging of Refrigerant Setting to Work & Adjusting
Section 4.6.3.2. Section 4.6.3.2.1 Section 4.6.3.2.2 Section 4.6.3.2.4 Section 4.6.3.2.5.
Submission of Record of Test 1.5 1.5.1 1.5.2 1.5.3 1.5.4
Test of Centrifugal Compressor System Pressure & Leakage Test Evacuation & Dehydration Charging of Refrigerant Setting to Work & Adjusting
Section 4.6.3.3 Section 4.6.3.3.1 Section 4.6.3.3.2 Section 4.6.3.3.4 Section 4.6.3.3.5
Submission of Record of Test 1.6
Test of Screw Compressor System 1.6.1 Pressure & Leakage Test 1.6.2 Evacuation & Dehydration
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
Section 4.6.3.5 Section 4.6.3.5.1 Section 4.6.3.5.2
Page 2 of 19
Filecode: SR21.Doc KFL/WKY
Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
1.6.3 Charging of Refrigerant 1.6.4 Setting to Work & Adjusting
Reference to Approved T&C Procedure Section 4.6.3.5.4 Section 4.6.3.5.5
S A S A S A S A S A S A S A S A
All refri.
Submission of Record of Test 1.7 1.7.1 1.7.2
1.7.3 1.7.4 1.7.5
Testing of Absorption Chillers General Check of System Components Leak Test of Absorption Shell and Purge Unit Evacuation of Absorption System Charging of Refrigerant Setting to Work & Adjusting
Section 4.6.3.4. Section 4.6.3.4. Section 4.6.3.4.1 Section 4.6.3.4.2 Section 4.6.3.4.4. Section 4.6.3.4.5
Submission of Record of Test 1.8
Functional Test for Air & Water Cooled Chillers
Section 4.6.3 & Part 4
Setting to work & record
1.8.1 Chilled Water Leaving Temperature 1.8.2 Chilled Water Entering Temperature 1.8.3 Chilled Water Flow Rate 1.8.4 Condenser Entering Temperature (Water Cooled Chillers) 1.8.5 Condenser Leaving Temperature (Water Cooled Chillers)
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
1.8.6 Compressor Motor Speed 1.8.7 Compressor Running Current 1.8.8 Air Flow Rate (Air Cooled Chillers) 1.8.9 Fan Speed (Air Cooled Chillers) 1.8.10 Fan Motor Speed (Air Cooled Chillers) 1.8.11 Fan Motor Running Current 1.8.12 Supply Voltage Submission of Record of Test 1.9
Functional Test for Air Absorption Chillers
Section 4.6.3 & Part 4
Setting to work & record
Submission of Record of Test 2. 2.1
Chilled Water System Cleanliness & State Check G/F 1/F 2/F 3/F 4/F
Section 4.5.1.1
Submission of Record of Test
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart "Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
2.2
Mechanical Check
Reference to Approved T&C Procedure Section 4.5.1.4
S A S A S A S A S A S A S A S A
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 2.3
General Checking
Section 4.5.1.3
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 2.4
Electrical Check (Pumps) 2.4.1 Electrical Supply Isolated
Section 4.5.1.6 Section 4.5.1.6.1
Prim.
Sec. Submission of Record of Test 2.4.2 Electrical Supply Available
Section 4.5.1.6.2
Prim.
Sec.
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
Submission of Record of Test 2.5
Initial Running of Pump Sets 2.5.1 Pump Discharge Rate
Section 4.6.1.4 Section 4.6.1.4.
Prim.
Sec. Submission of Record of Test 2.5.2 Pump Suction Pressure Prim Sec.
Section 4.6.1.4.
Submission of Record of Test 2.5.3 Pump discharge Pressure Prim Sec.
Section 4.6.1.4
Submission of Record of Test 2.5.4 Pump Motor Speed
Section 4.6.1.4.
Prim Sec.
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
Submission of Record of Test 2.5.5 Pump Motor Current Section 4.6.1.4. Prim Sec. Submission of Record of Test 2.5.6 Supply Voltage
Section 4.6.1.4.
Prim Sec. Submission of Record of Test 2.5.7 Non-return Valve Operation
Section 4.6.1
Prim.
Sec. Submission of Record of Test 2.5.8 Isolation Valve Operation
Section 4.6.1
Prim.
Sec. Submission of Record of Test
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
2.5.9 Flexible Joint
Reference to Approved T&C Procedure Section 4.6.1
S A S A S A S A S A S A S A S A
Sec. Submission of Record of Test 2.6 Chemical Treatment 2.6.1 Cleanliness & State Check 2.6.2 Mechanical Check 2.6.3 Electrical Check 2.6.4 General Check 2.6.5 Initial Running of Chemical Dosing Pump
Section 4.6
Submission of Record of Test 3. 3.1
Air Distribution System Cleanliness & State Check G/F 1/F 2/F 3/F 4/F
Section 4.5.2.1
Submission of Record of Test
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Fire & Smoke System Check 3.2.1 Regulating Device
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
3.2
Section 4.5.2.2
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.2.2 Visual Check on Air Tightness G/F 1/F 2/F 3/F 4/F
Section 4.5.2.3.
Submission of Record of Test 3.2.3 Leakage Test G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.2.4 Mechanical Check on Fans & Dampers G/F 1/F 2/F
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
Section 4.5.2.4.
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
3/F 4/F Submission of Record of Test 3.2.5 Initial Running of Fans & Dampers G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.2.6 Regulating of Air Flow G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.2.7 Functional & Performance Test G/F 1/F 2/F 3/F 4/F
Section 4.6.5
Submission of Record of Test
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Fire Tripping & Safety Cutout 3.3.1 Electrical Check
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
3.3
Section 4.5.2.5
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.3.2 Functional & Performance Test G/F 1/F 2/F 3/F 4/F
Section 4.6.5.
Submission of Record of Test 3.4
Fire & Smoke Dampers Check 3.4.1 Cleanliness & State Check G/F 1/F 2/F 3/F 4/F
Section 4.5.2.1
Submission of Record of Test
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
3.4.2 Functional & Performance Test G/F 1/F 2/F 3/F 4/F
Reference to Approved T&C Procedure Section 4.6.5
S A S A S A S A S A S A S A S A
Submission of Record of Test 3.4.3 Electrical Check
Section 4.5.2.5.
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.5
Mechanical Ventilation System Check 3.5.1 Cleanliness & State Check G/F 1/F 2/F 3/F 4/F
Section 4.5.2.1.
Submission of Record of Test 3.5.2 Regulating Device
Section 4.5.2.2
G/F
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
1/F 2/F 3/F 4/F Submission of Record of Test 3.5.3 Visual Check on Air Tightness G/F 1/F 2/F 3/F 4/F
Section 4.5.2.3
Submission of Record of Test 3.5.4 Leakage Test G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.5.5 Electrical Check
Section 4.5.2.5.
G/F 1/F 2/F 3/F 4/F Submission of Record of Test
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Reference to Approved T&C Procedure 3.5.6 Mechanical Check of Section Fans, Hydro Vent., 4.5.2.4. etc. G/F 1/F 2/F 3/F 4/F
S A S A S A S A S A S A S A S A
Submission of Record of Test 3.5.7 Initial Running of Fans G/F 1/F 2/F 3/F 4/F
Section 4.6.2.4
Submission of Record of Test 3.5.8 Regulating of Flow
Section 4.6.2.5.
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.5.9 Function & Performance Test G/F 1/F 2/F
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
Section 4.6.5.
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
3/F 4/F Submission of Record of Test 3.6
Check of Conditioned Air Distribution 3.6.1 Cleanliness & State Check G/F 1/F 2/F 3/F 4/F
Section 4.5.2.1
Submission of Record of Test 3.6.2 Regulating Device
Section 4.5.2.2
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.6.3 Visual Check on Air Tightness G/F 1/F 2/F 3/F 4/F
Section 4.5.2.3.
Submission of Record of Test
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
3.6.4 Leakage Test G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.6.5 Electrical Check
Section 4.5.2.5.
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.6.6 Insulation Check G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.6.7 Mechanical Check
Section 4.5.2.4.
G/F 1/F 2/F 3/F 4/F Submission of Record of Test
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
3.6.8 Initial Running of Fans & All Moving Parts G/F 1/F 2/F 3/F 4/F
Reference to Approved T&C Procedure Section 4.6.2.4.
S A S A S A S A S A S A S A S A
Submission of Record of Test 3.6.9 Regulating Air Flow Section 4.6.2.5. G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.6.10 Flow Balancing
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.6.11
Functional & Performance Test G/F 1/F 2/F
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
Section 4.6.5
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
Reference to Approved T&C Procedure
S A S A S A S A S A S A S A S A
3/F 4/F Submission of Record of Test 3.7
Check of Control System 3.7.1 Visual Inspection G/F 1/F 2/F 3/F 4/F
Section 4.6.4.1.1
Submission of Record of Test 3.7.2 Basic Function Test
Section 4.6.4.1.2
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 3.7.3 Electrical Check
Section 4.6.4.1.3. & Section 4.6.4.3
G/F 1/F 2/F 3/F 4/F Submission of Record of Test
Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix B
Testing and Commissioning Progress Chart “Air-conditioning, Refrigeration, Ventilation and Control Systems” Testing and Commissioning Progress Chart for Air-conditioning, Refrigeration, Ventilation and Control Systems (Rev. )(1) Remark Dates (2)
Activities
3.8
Noise & Sound Check G/F 1/F 2/F 3/F 4/F
Reference to Approved T&C Procedure Section 4.6.6
S A S A S A S A S A S A S A S A
Submission of Record of Test 3.9
Vibration Check
Section 4.6.7
G/F 1/F 2/F 3/F 4/F Submission of Record of Test 4.0
Submission of T&C Certificate
Notes * Delete if not applicable (1) Insert revision no. (2) Insert additional columns as necessary S - schedule % completion A - actual % completion Building Services Branch, Arch SD FORM NO. PBS/SR.021 Issue Date: 3 March 2000
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Appendix C Flow Chart for Testing and Commissioning Procedure on Air-conditioning, Refrigeration, Ventilation and Control Systems
Page 1 of 5
Appendix C
Figure 1. Example of Water Distribution System
Page 2 of 5
Appendix C
Figure 2. Example of Air Distribution System
Figure 3. Example of Air Distribution Branch
Page 3 of 5
Appendix C
Figure 4. Example of Low Velocity Supply Air System
Page 4 of 5
Appendix C
Figure 5. Example of Air Flow Sheet
Page 5 of 5
