Amana PGB58B High Pressure Protection Devices, Scroll Compressors, Reciprocating Compressor

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High Pressure Protection Devices

Scroll Compressors

PGC 24, 30, 36, 42, 60, and PGB58 units include scroll compressors. The installer and servicer should be aware of the following differences between scroll compressors and reciprocating compressors:

•These scroll compressors include a thermostat (ex- ternal compressor protector) mounted to the top of the compressor. THIS PROTECTIVE DEVICE SHOULD NEVER BE BYPASSED FOR ANY PUR- POSE.

•On a scroll compressor, due to its inherent ability to handle liquid refrigerant, a crankcase heater is not required.

CAUTION

To avoid severe personal injury or fire, refrigerant must be removed from both the low and the high pressure sides of the system before heat is applied.

•The scroll compressors use white oil which is com- patible with 3GS. If the addition of oil in the field is required, 3GS may be used .

Important Note: Never close the compressor suction line to test its pumping efficiency. This will seriously dam- age the compressor and void its warranty.

•The compressor may run backwards (noisy opera- tion) for 1 or 2 seconds at shutdown. This does not harm the compressor.

•These scroll compressors have copper plated steel suction tubes. If removal and reconnection becomes necessary, use silfos with minimum 5% silver or sil- ver braze material with flux.

•Operating pressures and current draws may differ from standard reciprocating compressors. See Sec- tion XV for typical cooling performance data.

Reciprocating Compressor

The PGC48 includes a reciprocating compressor with a crankcase heater. See the caution for the PGC48 be- fore starting cooling operation.

CAUTION

To avoid severe personal injury or fire, refrigerant must be removed from both the low and the high pressure sides of the system before heat is applied.

Operating Instructions (cooling)

CAUTION

On PGC48 Only: To avoid damage to the compressor, engage the electrical dis- connect switch to the compressor unit four hours prior to operating air condi- tioner after the electrical disconnect is off for a prolonged period of time (during vacation, etc.). This time lapse allows the compressor crankcase to attain a proper operating temperature.

(NOTE: Mechanical cooling cannot be reliably provided at ambient temperatures below 50° F. If low ambient cooling will be required a downflow economizer is avail- able. See Section XIV.)

1.Turn on the electrical power supply to the unit.

2.Place the room thermostat selector switch in the COOL position (or AUTO if available, and if auto- matic changeover from cooling to heating is desired).

3.Set the room thermostat to the desired temperature.

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