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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.
8.2.6 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.
8.3 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.
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.
4. Apply "live" test cord probes on red wire and common terminal of capacitor. Motor should
run at low speed.
5. Apply "live" test cord probes on each of the remaining wires from the speed switch or
system switch to test intermediate speeds.
