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 the gauge from the process tube to EPA approved gauges from the process tube to the EPA approved recovery system. Recover the CFC’s in the system to at least 5%.
2.Cut the process tube below the pinch off in 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 unsolder the more distant connection first. (Filter drier, high side process tube, etc.)
5.Replace the inoperative component, and always install a new filter drier. Drift dry nitrogen through the system when making these connections.
6.Pressurize the system to 30 PSIG with proper refrigerant and boost the refrigerant pressure to 150 PSIG with dry nitrogen.
7.Leak test the complete system with the electric halogen leak detector, correcting any leaks found.
8.Reduce the system to zero gauge pressure.
9.Connect the vacuum pump to the high side and low side of the system with deep vacuum hoses, or copper tubing. (Do not use regular hoses.)
10.Evacuate the system to an absolute holding pressure of 200 microns or less.
NOTE: This procedure can be sped up by the 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 the system a minimum of 10 minutes. Recover refrigerant, and proceed with evacuation to a pressure of 200 microns or a minimum of 10%.
11.Break the vacuum by charging the 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 the unit several times after allowing pressures to stabilize. Pinch off the process tubes, cut and solder the ends. Remove the pinch off tool, and leak check the process tube ends.
SPECIAL PROCEDURES IN THE CASE OF COMPRESSOR MOTOR BURNOUT
1.Recover all refrigerant and oil from the system.
2.Remove the compressor, capillary tube and filter drier from the system.
3.Flush the evaporator, condenser and all connecting tubing with dry nitrogen, or equivalent, to remove all contamination from the system. Inspect the suction and discharge lines for carbon deposits. Remove and clean if necessary.
4.Reassemble the system, including a new
5.Proceed with processing as outlined under hermetic component replacement.
ROTARY COMPRESSOR
SPECIAL TROUBLESHOOTING & 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 the correct connections.
REFRIGERANT CHARGE
1.The refrigerant charge is extremely critical. Measure the charge carefully and as exactly as possible to the nameplate charge.
2.The correct method for charging the rotary is to introduce liquid refrigerant into the high side of the system with the unit off. Then start the compressor and enter the balance of the charge, gas only, into the low side.
The introduction of liquid into the low side, without the use of a capillary tube, will cause damage to the discharge valve of the rotary compressor.
NOTE: All inoperative compressors returned to Friedrich must have all lines properly plugged with the plugs from the replacement compressor.
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