Air conditioner failure judgment

Common failure phenomena

Dirty blockage and ice blockage of the refrigeration system; blockage of the air filter; blockage of the air inlet and outlet by obstacles, etc.

Motor windings, fan motor windings, solenoid valve coils, relay coils and contacts were burned.

The fan is stuck, the bearing of the moving part is stuck, etc.

Fault judgment method

The basic methods for judging common failures of household air conditioners are: watching, listening, touching, testing, and analyzing.

1. Look: Carefully observe the working conditions of each component of the air conditioner, focusing on the three parts of the refrigeration system, electrical system, and wind system to determine whether they are working properly.

For refrigerating machine oil, use a clean soft cloth or soft paper to wipe the joints between the pipe welds and the joints, and observe whether there is any oil stains to determine whether there is leakage.

2. Listen: Turn on the power and listen to whether the air conditioner compressor is running normally, whether there is any abnormal sound, whether the fan is running noisy, whether the noise is too loud, etc. During the operation of the air conditioner, under normal circumstances, the vibration is slight and the noise is small, generally below 50DB. If the vibration and noise are too loud, the possible reasons are:

Foamed plastic cushions, etc., can increase the vibration and noise of the air conditioner during operation. Especially when it is just started and stopped.

When the chassis collides, the axis of the fan moves, and the blades are out of balance, and there will be an impact sound; if there are foreign objects in the fan, the blades will also cause an impact sound when they collide with it.

3. Touch: Touch the relevant parts of the air conditioner by hand to feel the heat, cold, tremor, etc., which is helpful to judge the nature and location of the fault. Under normal circumstances, the temperature of the condenser gradually decreases from top to bottom, and the temperature of the lower part is slightly higher than the ambient temperature. If the entire condenser is not hot or the upper part is slightly warm, or although it is hot but there is a significant difference in temperature between the upper and lower adjacent pipes, it is abnormal. The evaporator will feel cold and sticky if you put a finger dipped in water on the surface of the evaporator under normal conditions. Under normal circumstances, the capillary tube at the dryer and outlet should have a warm feeling (slightly higher than the ambient temperature, basically the same as the temperature of the pipe at the end of the condenser). Etc. are not normal. The temperature of the suction pipe 200mm away from the compressor should be similar to the ambient temperature under normal conditions.

4. Measurement: In order to accurately determine the nature and location of the fault, it is often necessary to use instruments and meters to check and measure the performance parameters and status of the air conditioner. For example, use a leak detector to check for refrigerant leakage; use a multimeter to measure whether the power supply voltage, the ground current of each terminal and the operating current meet the requirements, and the air conditioner controlled by the computer should also measure whether the potential of each control point is normal.

5. Analysis: Most of the results obtained through the above-mentioned inspection methods can only reflect a certain partial state. The various parts of the air conditioner are related to each other and affect each other. One failure phenomenon may have multiple reasons, and one reason may also cause multiple failures. Therefore, a comprehensive comparative analysis of local factors is required to determine the nature and location of the fault comprehensively and accurately.