OPERATION: Refrigeration
PUMP DOWN
During the pump down cycle (usually initiated by
the circuit board de-energizing the liquid line valve)
the discharge gases flow through their normal path
to the remote condenser, through the head
pressure control, and into the receiver. At this
point the refrigerant flow is stopped by the closed
liquid line valve. This action forces the refrigerant
into the receiver and keeps it out of the
compressor. The pump down continues until the
low pressure control turns the compressor off.
REMOTE CONDENSER
EVAPORATOR
DISCHARGE
LINE
LIQUID LINE
HEAD
PRESSURE
CONTROL
VALVE
RECEIVER
COMPRESSOR
Refrigeration Schematic
KING
VALVE
SUCTION
LINE
THERMOSTATIC
EXPANSION
VALVE
LIQUID LINE
VALVE
FM1202R
November 1992
Page 21