Compressor Replacement - Friedrich Kuhl KCM21A30A Service Manual

R-410A SEALED SYSTEM REPAIRS

Compressor Replacement

WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before service or
installation. Extreme care must be used, if it
becomes necessary to work on equipment with
power applied.
Failure to do so could result in serious injury or
death.
WARNING
HIGH PRESSURE HAZARD
Sealed Refrigeration System contains refrigerant
and oil under high pressure.
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with refrigerants.
Failure to follow these procedures could
result in serious injury or death.
WARNING
EXPLOSION HAZARD
The use of nitrogen requires a pressure
regulator. Follow all safety procedures and
wear protective safety clothing etc.
Failure to follow proper safety procedures
could result in serious injury or death.
CAUTION
FREEZE HAZARD
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with liquid refrigerant.
Failure to follow these procedures could
result in minor to moderate injury.
WARNING
NEVER, under any circumstances,
liquid charge a rotary-compressor
through the LOW side. Doing so
would cause permanent damage to
the new compressor. Use a charging
adapter.
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1. Be certain to perform all necessary electrical and refrigeration
tests to be sure the compressor is actually defective before
replacing.
2. Recover all refrigerant from the system though the process
tubes. PROPER HANDLING OF RECOVERED REFRIGERANT
ACCORDING TO EPA REGULATIONS IS REQUIRED. Do not use
gauge manifold for this purpose if there has been a burnout. You
will contaminate your manifold and hoses. Use a Schrader valve
adapter and copper tubing for burnout failures.
3.After all refrigerant has been recovered, disconnect suction and
discharge lines from the compressor and remove compressor. Be
certain to have both suction and discharge process tubes open to
atmosphere.
4.Carefully pour a small amount of oil from the suction stub of the
defective compressor into a clean container.
5.Using an acid test kit (one shot or conventional kit), test the oil
for acid content according to the instructions with the kit.
6.If any evidence of a burnout is found, no matter how slight, the
system will need to be cleaned up following proper procedures.
7.Install the replacement compressor.
CAUTION: While the unit is being evacuated, seal all openings on
the defective compressor. Compressor manufacturers will void
warranties on units received not properly sealed. Do not distort
the manufacturers tube connections.
8. Pressurize with trace amounts of R-410A and nitrogen to 550psi
and leak test all connections with a leak detector.Repair any leaks
found.
8a. If leak detector is unavailable remove all refrigerant from
system and pressurize with nitrogen to 550 psi. Check that system
holds pressure.
Repeat Step 8 to ensure no more leaks are present
9. Evacuate the system with a good vacuum pump capable of
a final vacuum of 300 microns or less. The system should be
evacuated through both liquid line and suction line gauge ports.
9a.Evacuate the system to 1500 microns.
9b. Repressurize to 50 PSI with nitrogen.
9c. Evacuate the system to 1000 microns.
9d. Repressurize to 50 PSI with nitrogen.
9e. Evacuate the system to below 500 microns.
10. Weigh in the refrigerant charge with the property
quantity of R-410A refrigerant per model nameplate.
11.Start unit, and verify performance.
12. Crimp the process tube and solder the end shut.