Haier AFD631 Service Manual

Haier AFD631 Service Manual Manual pdf 29 page image

ELECTRICAL CONTROL PRINCIPLEElectrical control principles of the refrigerator8.1 OverviewElectrical control principle of CFE/AFL/AFD refrigerators(1) Fully air cooling design, controlled with a fixed frequency compressor;(2) The temperature in the fridge storage compartment is controlled by controlling the air door with thefridge storage temperature sensor R;(3) The temperature in the freezer storage compartment is controlled by controlling the power of thecompressor with the freezer storage temperature sensor F;8.2 Main Control PCB of the RefrigeratorThere are 4 connectors on the main control panel of CFE/AFL/AFD refrigerators.Let’s describe these connectors:CN1 is the connector for the sensors and the door switch. Its pins from the left to right are:1: GND2: +12V3: Door switch signal. When the door is opened, GND and the signal wires are switch toconduction. When the door is open, the wires are disconnected;4-6: Null7-8: Connected to the fridge storage temperature sensor. We can test the sensor with these twowires. Its resistance in normal operation is between 6.35 and 3.88kΩ (correspond to 0℃～10℃). Theresistance at normal temperature is between 2.45 and 1.58kΩ (correspond to 20℃～30℃);7-9: Connected to defrosting temperature sensor. We can test the sensor with these two wires.Its resistance in normal operation is between 10.9 and 25.19kΩ (correspond to -10℃～-25℃). Theresistance at normal temperature is between 2.49 and 1.61kΩ (correspond to 20℃～30℃);10-11: Connected to the freezer storage temperature sensor. Resistance test is the same asthe defrosting temperature sensor;12: NullCN2 is the connector for the LED lamps and display panel:1: GND2: +5V3: Com4: Com5-6: Null7: +12V8: GNDCN3 is the connector for the power cables1: Zero line2: Live line3: Compressor (between it and the zero line)4: Null5: Heating tube for defrosting. The resistance between it and the zero is 345Ω±10%6: NullCN4 is the connector for the air door and fan:1: Feedback signal from the fan2: GND of the fan3: +12V of the fan4: fan +12V5-6: Null7-9: Motor of the refrigeration air door