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8.0 SYSTEM OPERATION
Refrigerant migration during the off cycle can result in a noisy start up. Add
a crankcase heater to minimize refrigeration migration, and to help eliminate
any start up noise or bearing “wash out”.
All heaters are located on the lower half of the compressor shell. Its purpose
is to drive refrigerant from the compressor shell during long off cycles, thus
preventing damage to the compressor during start-up.
At initial start-up or after extended shutdown periods, make sure the heater
is energized for at least 12 hours before the compressor is started.
(Disconnect switch on and wall thermostat off.)
The crankcase heater will start up or shut down according to the
following logic:
8.2 Protection
8.1 COMPRESSOR CRANKCASE HEATER(OPTIONAL)
8.2.1 Protection for HP system
If sensors(T3&T4) become open-circuit or short-circuit, the compressor ,outdoor
fan motor and reversing valve circuit will shut down.
Discharge temperature protectio n :
If discharge temp. is > 275°F, the compressor will shut down , If discharge temp. is
< 194°F, the compressor will resume operation .
High pressure protectio n
If high pressure is ＞638PSIG,the compressor and the outdoor fan motor
will stop running.
If high pressure is ＜464PSIG,the compressor and the outdoor fan motor
will resume running(3 minutes delay necessary ) .
T he crankcase heater will start up when the compressor is off and T4<41 ° F.
T he crankcase heater will shut down when
T4 ≥ 45 °F
I n any condition, the crankcase heater will shut down when the compressor is on
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