42
IM 676
Pumpdown
As the leaving water control is satisfied, it will unload the compressor(s) and then de-energize the
liquid line solenoid valve(s) SV1 and SV2, causing the valve(s) to close. When the compressor has
pumped most of the refrigerant out of the evaporator and into the condenser, the low pressure
control(s) LP1 and LP2 will open. If the refrigerant leaks into the low side causing the pressure to
close the low pressure controls LP1 and LP2, the compressor will start after a two-hour time delay.
For normal temperature controlled operation, the timer is bypassed and the compressor will start on
a refrigerant pressure rise.
Note: Do not shut the unit down without going through the pumpdown cycle. Flow switch,
time clock, and ambient lockout thermostat must be wired to allow pumpdown when unit is
turned off.
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