heatcraft-refrigeration-p h-im-79d User Manual

At the initial application of power to the system, the compressor and the evaporator fans
will be in a 4 minute hold-off cycle and will not start immediately.  When there is a call for
COOLING, the expansion valve (EEV) opens, then the compressor is started.  The
compressor will then run for a minimum of 2 minutes in the “hold-on” cycle. (This means
that the compressor will run for a minimum of 2 minutes before shutting off even if the box
temperature is met.)

The LED alternately displays 

BOX TEMPERATURE

  and 

MODE

  of operation. On a call for

cooling, 

dLY will show while the expansion valve is opening.  After the compressor starts

the LED will alternately display 

BOX TEMPERATURE

 and 

Coo.

On multiple evaporator systems the MASTER evaporator will display 

BOX

TEMPERATURE

 and 

Coo. The SLAVE evaporators will display Coo  only.

When the room thermostat setting is satisfied, and if the compressor ran for at least 2
minutes, the EEV will close and the compressor will pumpdown and shut off.  The
evaporator fans will continue to run. The LED will alternately display 

oFF  and 

BOX

TEMPERATURE.

When the room sensor detects a rise in temperature of approximately 2

°

F, and the

compressor has been off for at least 4 minutes, the EEV will open to its last position then
the compressor will start.  The valve is then adjusted as necessary to obtain the setpoint
superheat setting.  During this time, the compressor will run for a minimum 2 minutes “hold-
on” cycle.

The four minute “Hold-off” can be bypassed and the system started immediately by
pressing the “Reset” button on the Beacon II board.

- Off

- Cooling

- Pumpdown

- Defrost

- Draining

- Delay

- Test

- Service