In this article, we will discuss the different temperature sensors found in air conditioning systems and the error codes associated with them. These sensors are essential for the efficient operation of the system, and with the advent of inverter units, their variety has increased significantly to enhance control and performance.
Main Temperature Sensors in Air Conditioners
1. Ambient Temperature Sensor
This sensor measures the temperature of the return air to calculate the average temperature of the conditioned space.
Associated error codes:
- E1
- E2
- E4
2. Thermistor Sensor (Evaporator Temperature Sensor)
Located in the evaporator, this sensor measures the temperature to detect potential freezing issues.
Associated error codes:
- E2
- E3
- E5
3. Condenser Temperature Sensor
This sensor measures the temperature of the air passing through the condenser, helping regulate thermal efficiency.
Associated error codes:
- F1
- F6
4. Condenser Outlet Sensor
Responsible for measuring the temperature of the liquid refrigerant exiting the condenser to calculate subcooling.
Associated error codes:
- F2
5. Compressor Discharge Sensor
This sensor measures the temperature of the refrigerant at high pressure and temperature in the compressor’s discharge pipe. It is critical for compressor protection, especially in systems using refrigerants like R32.
Associated error codes:
- F3
- F4
6. Compressor Suction Sensor
This sensor measures the temperature of the refrigerant in the compressor’s suction line to monitor superheat and improve system efficiency.
Associated error codes:
- FA
Temperature Sensor Diagnostics
1. Connection Inspection
- Check that the sensor connections are clean and in good condition.
- Ensure the sensor is properly positioned.
2. Resistance Measurement
- Use a multimeter on the kilohm scale to measure the resistance of the sensor, disconnected from the control board.
- Compare the measured value with the manufacturer’s specifications. If the exact value is unavailable, lightly heat the sensor to observe if the resistance decreases as the temperature rises.
3. Power Supply Voltage Check
- With the sensor connected, use a multimeter on the DC voltage scale to check the control board’s power supply.
- The expected voltage is approximately 2.5V DC.
4. Sensor Functionality Check
- If both the resistance and power supply are correct but the error persists, assess the overall condition of the control board.
