Defrost Thermostat Case Study
Defrost …show more content…
The defrost thermostat is usually wired in series with the element and is an open circuit about 36°- 48° degrees Fahrenheit. Since the temperature is not low enough to close the circuit, it becomes difficult to check the continuity of the thermostat using a multi-meter. You may need a modern thermostat that come with internal bias resistor. This aids in testing both the heater and the thermostat. The wiring diagram that comes with the product will indicate this.
When you check the continuity of the heater circuit, it will show high resistance if the thermostat is open and heater is good, low resistance if the thermostat is closed and heater is good, and no continuity if the heater is open. Before performing the tests, make sure you disconnect the power supply to the machine.
This part can be found either next or below the evaporator coils. It is controlled by the adaptive defrost control or the defrost timer and the termination thermostat. The defroster heater is a glass-encased wire with well-insulated wire leads. You can check the condition of the defrost heater using a multi-meter. Before you check its condition, make sure you switch off the power supply to the …show more content…
If there is a problem with the evaporator fan, the control sensor or thermostat will not be able to sense the temperature and the compressor will run longer than normal. Also, the temperature in the freezer and fresh food compartment will also increase.
The evaporator fan and motor are located in the freezer compartment and you can feel the air movement when the motor and fan are running. If you have reason to believe that fan motor is not performing its tasks properly, you must switch off the power supply to the refrigerator and remove the evaporator fan cover. Make sure the fan blades are secure and motor is working properly. You can check the condition of the fan motor using a multi-meter. You must also check the power applied to the motor when the compressor is running. Since this is a live voltage check, it must be performed by professionals.