beautypg.com

All cooler models – Heatcraft Refrigeration Products Refrigeration System H-IM-82B User Manual

Page 11

background image

11

Reprinted with permission from Dixell.

3.

C

oolers

Air Defrost Sequence of Operation
for Coolers

Air defrost units are preprogrammed for 3 hours of

compressor run time between defrosts. These periods are

not reprogrammable. After 3 hours, the temperature control

will turn the compressor off. When the coil temperature

reaches 38°F, the control will terminate the defrost cycle.

Room Thermostat Settings:

• Approximate dial settings of control
0 = Unit off (not an electrical disconnect)

1 = 52°F (11°C)

2 = 49°F (9°C)

3 = 45°F (7°C)

4 = 41°F (5°C)

5 = 38°F (3°C)

6 = 34°F (1°C)

Cooler Defrost Control

Cooler units utilize an electronic temperature control.

The temperature may be adjusted by setting the dial. This

control is preset to provide 3 hours of compressor run time

between defrost cycles. Defrosts are temperature terminated

and cannot be reprogrammed. The temperature control

is programmed for minimum on cycle of one minute and

minimum off cycle of four minutes.

Maintenance

The evaporator section of a

system should be checked

at least once for proper defrosting because the amount

and pattern of frosting can vary greatly. The frost build-up

is dependent on the temperature of the room, the type of

product being stored, how often new product is brought

into the room and percentage of time the door to the room

is open.

System Standard Maintenance Guidelines

After first year of operation and under normal usage,

maintenance should cover the following items at least once

every six months:
1. Check and Tighten ALL electrical connections.
2. Check all wiring and insulators.
3. Check contactors for proper operation and for worn

contact points.
4. Check all fan motors. Tighten motor mount bolts/nuts

and tighten fan set screws.
5. Clean the condenser coil surface.
6. Check the operation of the control system. Make

certain all safety controls are operating properly.
7. Check that all defrost controls are functioning properly.
8. Clean the evaporator coil surface.
9. Clean the drain pan and check the drain pan and

drain line for proper drainage.

All Cooler Models

NOTE: If power is interrupted to the unit during the

refrigeration off-cycle (system at temperature setpoint,

compressor off), the thermostat will initiate an extra defrost

period approximately one hour after power is restored.