Section C - Electronic Controls
Defrost Termination Thermostat (DTT)
Bi-metal disc thermostat attached via a clamp to the evaporator tubing. During the
defrost cycle, the device is a closed circuit between the defrost heater and Neutral.
The DTT is designed to open at a predetermined temperature ending the defrost cycle
Standard Compressor
Motorized pump (115VAC) that creates the high and low pressures required for
heat exchange. The Standard Compressor is controlled by a relay.
Evaporator Fan
Motorized Fan (12 VDC) that circulates freezer and fresh food section air. The
evaporator fan motor speed is controlled via a +12 VDC circuit.
N OTE
If the fan motor is running when the freezer door is opened, the speed will
change from HIGH (2700 RPM) to LOW (2000 RPM).
Condenser Fan
Motorized Fan (115 VAC) that circulates air through the condenser coils. Either a
Relay or Triac, depending on compressor used, controls condenser Fan Motor.
Fresh Food Door Sensor
Magnetically activated reed switch. Switch will detect Fresh Food Door state.
Air Filter
Motorized Fan (12VDC) that circulates air through a filter in the Fresh Food Section.
The Filter Fan Motor is controlled via a power transistor. (Not on all models.)
Sensors
Negative Temperature Coefficient Thermistor. (10kΩ ±2% @ 25°C.)
Fresh Food Lights
Fresh Food Lights are enabled and disabled depending on the Fresh Food Door
Sensor state. Light on maximum is 15 minutes. Interior lights will shut off after 15
minutes if the door is left open. Closing and re-opening the door will reset the
sequence.
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