Today we will talk about the use of temperature sensors in air conditioners. 1. Room temperature sensor It is installed at the air inlet of the air conditioner indoor air conditioner evaporator, supported by plastic parts, and is suitable for detecting whether the temperature in the room has reached the preset value. What it does is shown below. ①Automatic control system when the indoor air temperature is refrigerated. ②The auxiliary electric heater is used in the heating process. 2. The temperature sensor of the air conditioner evaporator pipeline in the room. It is assembled on the air conditioner evaporator duct in the room. The outside is encapsulated by a metal hose and is in contact with the pipeline, so the temperature is accurately measured close to the degree of volatilization of the refrigeration unit. What it does is shown below. ①Summer cooling process management. (Avoid insufficient refrigerant in the system or frost on the evaporator in the room) ②Anti-cold wind operation is used for heating in winter. ③ Control the speed of the fan motor in the room. ④ Cooperate with the design of the single-chip microcomputer to complete the fault self-diagnosis. ⑤Assist the outdoor unit to defrost the outdoor unit. 3. An outdoor natural environment temperature sensor is installed on the heat pipe radiator of the outdoor unit. Use plastic support points for outdoor natural environment temperature. Its basic functions are as follows. ① Operate the speed ratio of the outdoor fan motor after cooling or heating. ②When the automatic control system is automatically maintained, the outdoor temperature is too low or too high. 4. Outdoor cooler duct temperature sensor It is installed on the heat pipe radiator of the outdoor unit and is packaged with a metal hose to detect the temperature of the outdoor pipeline. Its basic functions are as follows. ①Use the outdoor unit to defrost when heating. ②Overheating protection or freezing protection is used for cooling or heating. 5. The temperature sensor of the exhaust pipe of the outdoor refrigeration compressor is assembled on the exhaust pipe of the outdoor refrigeration compressor and packaged with a metal hose. The basic functions are as follows. ①The automatic control system is automatically maintained when the temperature of the exhaust pipe of the refrigeration compressor is too high. ②In the frequency conversion central air conditioner, it is used to control the opening of the air conditioner thermostat and the increase of the operating frequency of the refrigeration compressor. Detect common failures of central air conditioning temperature sensors. 1. Road detection of temperature sensor Remove the circuit board in the indoor unit of the air conditioner from the fixed control module, then connect each component, turn on the switching power supply, detect the temperature sensor of the air conditioner, and see the voltage sent to the microcontroller any questions. It can be judged whether the temperature sensor is good or not. It is worth noting that personal safety should be paid attention to during the road inspection process. When using a multimeter to detect the temperature sensor, the detection should be carried out on the spot welding on the back of the computer board. Ground the gray-black electric pen of the multimeter, connect the bright red electric pen to the spot welding of the temperature sensor, and select the digital multimeter transmission gear 20V voltage gear. Under normal circumstances, the voltage of the temperature sensor in the room to the microcontroller should be around 2V, if the sensor is damaged. The measured voltage value is 0V. The voltage value of the air conditioner evaporator pipeline temperature sensor to the microcontroller should be around 3V, if the sensor is damaged. The measured value is 0V. The measured sensor voltage value of 0V indicates that the external sensor is damaged and should be replaced. 2. In addition to the road detection, the lead detection of the temperature sensor also solves the lead detection of the temperature sensor to accurately measure its resistance under different temperature conditions. This can judge whether the temperature sensor is good or not. The detection method is the same as the road detection method, and a multimeter is used for measurement. If the resistance of the temperature sensor is always very large, then it is usually infinite. This means that if the temperature sensor is abnormal, the temperature sensor leads the way to detect normal. In the road detection link, if the pin voltage value is too high or too low, a part of the power supply circuit should be further detected to clear common faults.
Post time: Aug-05-2022