Sinclair AMC-15A, Service Manual

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Basic test procedure
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.
11.2.4 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.
11.2.5 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.
11.2.6 Refrigerant charge
1. The refrigerant charge is extremely critical. It must be measured charge carefully - as exact 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 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.
11.3 Fan motor
A single phase permanent split capacitor motor is used to drive the evaporator blower and
condenser fan. A self-resetting overload is located inside the motor to protect against high
temperature and high amperage conditions.
11.3.1 Fan motor test
1. Determine that capacitor is serviceable.
2. Disconnect fan motor wires from fan speed switch or system switch.
3. Apply "live" test cord probes on black wire and common terminal of capacitor. Motor should
run at high speed.