8
4.9 Relay
The contacts of the single pole, single throw relay
complete the power circuit to the compressor. The
contacts are closed when power is provided to the relay
coil via the control circuit. The control circuit includes
the power switch, low pressure control, time delay (HP
model), defrost thermostat and timer.
4.10 Time
Delay (HP model only)
The HP model has a time delay relay in the
compressor control circuit. This relay delays the
compressor start about 2 minutes after the power
switch is turned on. This reduces the unit’s starting
amp draw by starting the blower and compressor at
different times. This reduces the chance of tripping a
circuit breaker during hard start situations, such as
when the unit has been stored in a cold place. It also
reduces compressor short cycling after the compressor
has stopped.
