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

M = Master Evaporator

CU= Condensing unit

• Check all wiring connections to be sure they are correct and tight.
• On condensing unit

- Check the setting of Time Delay relay. It should be set at 1 minute (the

second marker).

- Check the Low Pressure switch setting on freezer units. It must be set to 0

PSIG cutout, 10 PSIG cut-in to allow positive start and operation, especially
in cold ambients. This can be changed to a higher value in warmer climates.
On cooler units, the Low Pressure switch has a fixed setting and cannot be
adjusted.

• Turn power on
• On the evaporator

- Use the “PROGRAM REVIEW” button to scroll through settings.
- Check “

rEF” (Refrigerant Type). Factory defaults are: Air Defrost R-22,

Electric Defrost R-404A. Change to the refrigerant being used.

- Check 

“bot” (Box Temperature). Factory defaults are: air defrost 35

°

F and

electric defrost –10

°

F. Change to the desired temperature.

- Review and change other setting if necessary
- See procedures below on how to change settings.