maintenance
Maintenance procedures
Refrigerant System
Special Note on Refrigerant Emissions Follow the Trane recommended procedures on operation, maintenance, and service to ensure refrigerant conservation and emission reduction. Also, pay specific attention to the following:
•Whenever removing refrigerant from equipment, recover for reuse, recycle, reprocess (reclaim), or properly destroy it.
•Always determine possible refrigerant recycling or reclaiming requirements before beginning recovery. Questions about recovered refrigerants and acceptable refrigerant quality standards are addressed in ARI Standard 700.
•Use approved containment vessels and safety standards. Comply with all applicable transportation standards when shipping refrigerant containers.
•To minimize emissions while recovering refrigerant, use recycling equipment. Always attempt to use methods that pull the lowest possible system vacuum while recovering and condensing refrigerant into containment.
•When leak checking with trace refrigerant and nitrogen, use HCFC22 (R22) rather than CFC12 (R12) or any other fully halogenated refrigerants. Be aware of any new leak test methods that eliminate refrigerant as a trace gas.
•When cleaning system components or parts, do not use CFC11 (R11) or CFC113 (R113). Refrigeration system clean up methods using filters and dryers are recommended. Do not use solvents that have ozone depletion factors. Properly dispose of used materials.
•Take extra care to properly maintain all service equipment directly supporting refrigerant service work such as gauges, hoses, vacuum pumps, and recycling equipment.
•Stay aware of unit enhancements, conversion refrigerants, compatible parts, and manufacturer’s recommendations that reduce refrigerant emissions and increase equipment operating efficiencies. Follow specific manufacturer’s guidelines for conversion of existing systems.
•To assist in reducing power generation emissions, always attempt to improve equipment performance with improved maintenance and operations that will help conserve energy resources.
WARNING
Confined Space Hazards!
Do not work in confined spaces where sufficient quantities of refrigerant or other hazardous, toxic, or flammable gas may be leaking. Refrigerant or other gases could displace available oxygen to breathe, causing possible asphyxiation or other serious health risks. Some gases may be flammable and or explosive. Evacuate the area immediately and contact the proper rescue or response authority. Failure to take appropriate precautions or to react properly to a potential hazard could result in death or serious injury.
WARNING
Hazard of Explosion!
Use only dry nitrogen with a pressure regulator to pressurize the unit. Do not use acetylene, oxygen, compressed air, or mixtures containing them.
Do not use mixtures of a hydrogen containing refrigerant and air above atmospheric pressure for pressure testing as they may become flammable and could result in an explosion. Refrigerant, when used as a trace gas should only be mixed with dry nitrogen for pressurizing units. Failure to follow these recommendations could result in death, serious injury, equipment, or
WARNING
Leak Testing!
Do not exceed 200 psig when leak testing system. Failure to follow these instructions could result in an explosion causing death or serious injury.
In the event of required system repair, leak test the liquid line, evaporator coil, and suction line at pressures dictated by local codes, and using the following guidelines.
1.Charge enough refrigerant and dry nitrogen into the system to raise the pressure to 100 psig.
2.Use a halogen leak detector, halide torch, or soap bubbles to check for leaks. Check interconnecting piping joints, the evaporator coil connections, and all accessory connections.
3.If a leak is detected, release the test pressure, break the connections and reassemble it as a new joint, using proper brazing techniques.
4.If no leak is detected, use nitrogen to increase the test pressure to 150 psig and repeat the leak test. Also, use soap bubbles to check for leaks when nitrogen is added.
5.Retest the system to make sure new connections are solid.
6.If a leak is suspected after the system has been fully charged with refrigerant, use a halogen leak detector, halide torch, or soap bubbles to check for leaks.
Refrigerant Evacuation
For field evacuation, use a rotary style vacuum pump capable of pulling a vacuum of 100 microns or less.
When connecting the vacuum pump to a refrigeration system, it is important to manifold the pump to both the high and low side of the system. Follow the pump manufacturer’s directions.
WARNING
Use of Pressure Regulator – Valves – Gauges!
Always use pressure regulators, valves, and gauges to control drum and line pressures when pressure testing equipment. Failure to follow these instructions could result in an explosion causing death, serious injury, or equipment damage.
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