4. Frost Formation on Low-Pressure Pipe, Reduced Dehumidification Efficiency

Fault Diagnosis:

1. Frost on the rear section of the capillary tube with oil traces at the interface with the low-pressure pipe indicates refrigerant leakage.

2. Frost starting from the front section of the capillary tube, with no oil traces in the pipeline, suggests a clogged filter.

Repair Measures:

1. Locate and repair the leak, perform pressure testing, and recharge the refrigerant.

2. Replace the clogged filter.

5. Dehumidifier Still Not Dehumidifying After Repair

Situation Description:

A household dehumidifier, previously repaired for dirt clogging, now operates normally with the compressor and fan but fails to dehumidify.

Fault Diagnosis:

1. The air filter and evaporator surface are clean.

2. The compressor's operating current is significantly lower than during the previous fault, indicating severe refrigerant leakage.

Repair Measures: 

Locate and repair the leak to resolve the issue.

Cause Analysis:

Significant refrigerant leakage reduces the compressor's displacement and load, resulting in a lower operating current.

6. Poor Dehumidification Effect, Compressor Automatically Stops

Fault Diagnosis:

1. The evaporator surface has uniform condensation, indicating no clogging.

2. The condenser pipes have normal temperature differences, indicating no clogging.

3. The compressor automatically stops after a period of operation, while the fan and control system function normally.

4. The compressor's overheat protection has not activated; the internal protector may have triggered.

5. Inspection reveals a difference in winding resistance between when the compressor stops and when it is cold.

Repair Measures:

Replace the compressor with a new one to restore dehumidification function.

Cause Analysis:

The original compressor's unstable winding resistance causes rapid temperature rise during power-on, triggering the internal protector and causing automatic shutdown.

7. Excessive Vibration During Operation, Poor Dehumidification Effect

Fault Diagnosis:

1. No condensation on the evaporator surface.

2. The high-pressure pipe is only lukewarm (normally hot), indicating refrigerant leakage.

3. Inspection reveals oil traces at the interface between the high-pressure pipe and the condenser, caused by vibration-induced cracking.

Repair Measures:

1. Use the oil trace method (or soap bubble method) to locate and repair cracks.

2. Perform pressure testing, evacuate the system, and refill with refrigerant.

3. Identify the cause of excessive vibration and find that the unloading device fails to operate due to a faulty solenoid directional valve.

4. Replace the solenoid directional valve with the same model, re-check for leaks, evacuate the system, refill with the specified amount of refrigerant, and restart the machine to resolve the issue.

Dorosin's Two Decades of Dedication to the Dehumidification Industry

Dorosin has been deeply committed to the dehumidification industry for over two decades, specializing in providing comprehensive temperature control solutions. Our products are exported to numerous countries worldwide and are highly regarded by our customers. For more information on temperature control, stay tuned for our upcoming updates.