1. Winding short circuit, open circuit and winding touching the chassis ground: This type of fault is caused by the motor part of the compressor. The fault phenomenon is that the power supply is normal when the circuit is open. The compressor does not work; the protector is energized when short circuit and touch the shell Action, or blow the fuse; it should be noted that if there is a slight short circuit between the turns of the winding, the compressor can still work, but the working current is large, the temperature of the compressor is very high, and the thermal protector will act shortly. The short circuit of the winding and the contact of the winding with the chassis ground can generally be checked with a multimeter; the short circuit of the winding, especially the slight short circuit, is not easy to determine because the resistance of the winding itself is small, and it should be determined based on the measured current.
2. Compressor holding shaft and jammed cylinder: If the compressor loses oil or foreign matter enters, it will often cause shaft holding or jamming cylinder. The failure phenomenon is that the compressor does not run after power on and the protector acts.
3. The compressor suction and exhaust valves are not closed tightly: if the compressor suction and exhaust valves are damaged, even if the refrigerant is sufficient, the system cannot establish high or low pressure or it is difficult to establish a qualified high and low pressure. The system does not cool or the cooling effect is very poor .
4. Vibration and noise of the compressor: This type of problem often occurs during maintenance work. Generally, it does not have much impact on the refrigeration performance, but it will make the user feel abnormal. The cause is often the collision of the pipe and the casing, the compressor The fixing bolts are loose and the shock-absorbing block falls off.
5. The thermal protector is damaged: the thermal protector is an accessory of the compressor, and the fault is generally an open circuit or the operating temperature point becomes smaller. Open circuit will cause the compressor to not work; the smaller operating temperature point will cause the compressor to stop after a period of time and repeat this. This problem is often confused with a slight short circuit between winding turns, the difference is that the working current is when the thermal protector is damaged Normally, the current is too large when the winding is short-circuited.
Common methods for repairing air conditioning compressors
Compressor shaft and stuck cylinder failure can be repaired first, the specific methods are as follows:
(1) Percussion method: knock the lower part of the compressor with a wooden hammer after starting up, so that the internal stuck parts of the compressor are vibrated and run.
(2) Capacitor start method: A capacitor with a larger capacitance than the original can be used to start the circuit.
(3) High-voltage startup method: You can use a voltage regulator to increase the power supply voltage and start.
(4) Pressure relief method: start after the system refrigerant is completely emptied.