Friedrich Twintemp, Service Manual

Page: 39 / 68

37
recommended procedure for compressor
replacement
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.
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. 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.
10. Recharge the system with the correct amount of
refrigerant. The proper refrigerant charge will be
found on the unit rating plate. The use of an accurate
measuring device, such as a charging cylinder,
electronic scales or similar device is necessary.
COMPrESSOr rEPLACEMENT
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.
8. Pressurize with a combination of R-22 and nitrogen
and leak test all connections with an electronic or
Halide leak detector. Recover refrigerant and repair
any leaks found.
Repeat Step 8 to insure no more leaks are present.
Unplug and/or disconnect all electrical power
to the unit before performing inspections,
maintenances or service.
Failure to do so could result in electric shock,
serious injury or death.
WARNING
RISK OF ELECTRIC SHOCK
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
HIGH PRESSURE HAZARD
Extreme care, proper judgment and all safety
procedures must be followed when testing,
troubleshooting, handling or working around
unit while in operation with high temperature
components. Wear protective safety aids
such as: gloves, clothing etc.
Failure to do so could result in serious burn
injury.
WARNING
HIGH TEMPERATURES
The use of a torch requires extreme care and proper
judgment. Follow all safety recommended precautions
and protect surrounding areas with fire proof materials.
Have a fire extinguisher readily available. Failure to follow
this notice could result in moderate to serious property
damage.
NOTICE
FIRE 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
result in serious injury or death.
WARNING
EXPLOSION 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.
CAUTION
FREEZE HAZARD