Maintenance example of poor cooling effect of inverter air conditioner
Today, I will tell you about the maintenance example of the poor cooling effect of the air conditioner.
1. The cooling is poor, and the operating frequency is not up to the highest. The exhaust pipe overheating code will be displayed for about 20 minutes.
Failure analysis: system refrigerant is insufficient; exhaust pipe detection circuit is abnormal; compressor failure.
Troubleshooting: Observe that there is no oil stain on the nozzles of the second and third stop valves of the outdoor unit. The fixed frequency operation test system pressure is slightly lower. The return pipe of the outdoor unit does not form frost, which is a manifestation of insufficient refrigerant in the system. Add refrigerant to the refrigerant to a pressure of 4.5kg/cm. The operating frequency can reach the highest value, and the cooling effect returns to normal.
2. If the refrigeration is poor, it enters the self-checking state to alarm the compressor overcurrent.
Fault analysis: over-current → compressor frequency limited operation → cooling difference.
Troubleshooting: The compressor current measured is 9.5A, which is greater than the rated refrigerant current of 4.5A marked on the nameplate of the machine, indicating that the unit is indeed operating at too high current. The resistance between the three ends of the compressor is measured. One group of values is too small, normal The three-terminal resistance value should be balanced. Replace the compressor, troubleshooting.
3. The cabinet machine has poor refrigeration, and the internal fan rotates slowly and sometimes does not rotate.
Failure analysis: the internal fan is damaged or the capacity of the fan capacitor becomes smaller.
Troubleshooting: Measure the working voltage of the fan to be 220VAC as the normal value. Rotating the inner fan bearing can automatically rotate a few times. It is estimated that the capacity of the fan capacitor on the indoor computer board is insufficient. Remove it and use the indicator resistance file × 10KΩ to test. The small swing range indicates that the capacity is indeed small. After the replacement, the air conditioner resumes normal operation.
