EQUIPMENT MUST BE CAPABLE OF:
1.Recovery CFC's as low as 5%.
2.Evacuation from both the high side and low side of the system simultaneously.
3.Introducing refrigerant charge into high side of the sys- tem.
4.Accurately weighing the refrigerant charge actually in- troduced into the system.
5.Facilities for flowing nitrogen through refrigeration tub- ing during all brazing processes.
HERMETIC COMPONENT REPLACEMENT
The following procedure applies when replacing components in the sealed refrigeration circuit or repairing refrigerant leaks. (Compressor, condenser, evaporator, capillary tube, refrigerant leaks, etc.)
1.Recover the refrigerant from the system at the process tube located on the high side of the system by installing a line tap on the process tube. Apply gauge from process tube to EPA approved gauges from process tube to EPA approved recovery system. Recover CFC's in system to at least 5%.
2.Cut the process tube below pinch off on the suction side of the compressor.
3.Connect the line from the nitrogen tank to the suction process tube.
4.Drift dry nitrogen through the system and
5.Replace inoperative component, and always install a new filter drier. Drift dry nitrogen through the system when making these connections.
6.Pressurize system to 30 PSIG with proper refrigerant and boost refrigerant pressure to 150 PSIG with dry nitrogen.
7.Leak test complete system with electric halogen leak detector, correcting any leaks found.
8.Reduce the system to zero gauge pressure.
9.Connect vacuum pump to high side and low side of system with deep vacuum hoses, or copper tubing. (Do not use regular hoses.)
10.Evacuate system to maximum absolute holding pressure of 200 microns or less. NOTE: This process can be speeded up by use of heat lamps, or by breaking the vacuum with refrigerant or dry nitrogen at 5,000
microns. Pressure system to 5 PSIG and leave in system a minimum of 10 minutes. Release refrigerant, and proceed with evacuation of a pressure of 200 microns or less.
11.Break vacuum by charging system from the high side with the correct amount of refrigerant specified. This will prevent boiling the oil out of the crankcase.
NOTE: If the entire charge will not enter the high side, allow the remainder to enter the low side in small increments while operating the unit.
12.Restart unit several times after allowing pressures to stabilize. Pinch off process tubes, cut and solder the ends. Remove pinch off tool, and leak check the process tube ends.
SPECIAL PROCEDURE IN THE CASE OF
COMPRESSOR MOTOR BURNOUT
1.Recover all refrigerant and oil from the system.
2.Remove compressor, capillary tube and filter drier from the system.
3.Flush evaporator condenser and all connecting tubing with dry nitrogen or equivalent, to remove all contamination from system. Inspect suction and discharge line for carbon deposits. Remove and clean if necessary.
4.Reassemble the system, including new drier strainer and capillary tube.
5.Proceed with processing as outlined under hermetic component replacement.
ROTARY COMPRESSOR SPECIAL
TROUBLESHOOTING AND SERVICE
Basically, troubleshooting and servicing rotary compressors is the same as on the reciprocating compressor with only a few exceptions.
1.Because of the spinning motion of the rotary, the mounts are critical. If vibration is present, check the mounts carefully.
2.The electrical terminals on the rotary are in a different order than the reciprocating compressors. The terminal markings are on the cover gasket. Use your wiring diagram to insure correct connections.
REFRIGERANT CHARGING
NOTE: BECAUSE THE RAC SYSTEM IS A SEALED SYSTEM, SERVICE PROCESS TUBES WILL HAVE TO BE INSTALLED. FIRST INSTALL A LINE TAP AND REMOVE REFRIGERANT FROM SYSTEM. MAKE NECESSARY SEALED SYSTEM REPAIRS AND VACUUM SYSTEM. CRIMP PROCESS TUBE LINE AND SOLDER END SHUT. DO NOT LEAVE A SERVICE VALVE IN THE SEALED SYSTEM.
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