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MECHANICAL TEMPERATURE CONTROL GENERAL SEQUENCE OF OPERATION
MECHANICAL CONTROL REFRIGERATOR GENERAL SEQUENCE OF OPERATION
1. Cabinet is plugged in.
a. Interior lights will illuminate on Glass Door Models only. If lights do not come on verify the light switch is in the “ON”
position. Solid door cabinets may or may not have lights that may be controlled by the door switch.
2. The compressor and evaporator fans will start if the temperature control is calling for cooling. (If the compressor does not
start, verify that the temperature control is not in the “OFF” or “0” position.)
3. The temperature control may cycle the compressor and evaporator fan(s) on and off together.
a. The temperature control is sensing the evaporator coil temperature.
b. The temperature control should be set on the #4 or #5.
c. The warmest setting is #1, the coldest is #9, and #0 is the off position.
d. The thermometer is designed to read and display a cabinet temperature not a product temperature.
The thermometer may reflect the refrigeration cycle swings of up and down temperatures.
The most accurate temperature on a cabinet's operation is to verify the product temperature.
4. There is not a defrost timer as the temperature control will initiate the off-cycle defrost during each refrigeration cycle.
a. At this time, the compressor will and the evaporator fan(s) may turn off. Defrost heaters are not installed on refrigerators
and therefore will not be energized.
b. After the evaporator coil temperature has been reached, as determined by the temperature control, the compressor will
restart.
5. There may be a timer located on the condensing unit base. This timer is not used for a defrost event. The timer will change
the rotation of the reversing condenser fan motor.
MECHANICAL CONTROL FREEZER GENERAL SEQUENCE OF OPERATION
1. Cabinet is plugged in.
a. Interior lights will illuminate on glass door models only. If lights do not come on, verify the light switch is in
the “ON” position. Solid door cabinets may or may not have lights that may be controlled by the door switch.
2. The compressor only will start if the temperature control is calling for cooling. (If the compressor does not start, verify that
the temperature control is not in the “OFF” or “0” position or the cabinet is not in a defrost event.)
a. The evaporator fan(s) will remain off until a specific temperature of the evaporator coil is reached.
3. The temperature control may cycle the compressor and evaporator fan(s) on and off together.
a. The temperature control is sensing the air temperature.
b. The temperature control should be set on the #4 or #5.
c. The warmest setting is #1, the coldest is #9, and #0 is the off position.
d. The thermometer is designed to read and display a cabinet temperature not a product temperature.
The thermometer may reflect the refrigeration cycle swings of up and down temperatures.
The most accurate temperature on a cabinet's operation is to verify the product temperature.
4. The defrost timer will initiate defrost during specific times of day.
a. At this time, the compressor and evaporator fan(s) will turn off and the evaporator coil heater and drain tube heater will
be energized. Some cabinets may also change the rotation of the reversing condenser fan motor.
b. After the predetermined evaporator coil temperature has been reached or duration for defrost has expired, the
compressor will restart and the evaporator fan(s) will remain off until a specific temperature of the evaporator coil is
reached.
