Heatcraft Refrigeration Products H-IM-79E Initial Power On, Operating Mode Display, Cooling, Test

Start-Up Operation

Initial Power On

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.

Operating Mode Display

oFF	- Off
Coo	- Cooling
Pdn	- Pumpdown
dEF	- Defrost
drn	- Draining
dLY	- Delay
tSt	- Test
SEr	- Service

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