Common Causes and Analysis of Compressor Thermal Protection

2024-12-20

I. Common Causes and Analysis of Compressor Thermal Protection:

The return gas volume of the system is insufficient, and the motor is not adequately cooled.
The power supply voltage is abnormal, there is a phase loss, or the motor is overloaded.
The condensing pressure is too high, etc.
Overheating phenomena such as high motor temperature, excessive exhaust temperature, and burnt lubricating oil are caused.

II. Common Causes and Analysis of Poor Refrigeration Effect:

The expansion valve is opened too wide or too narrowly.
The refrigeration system is blocked and not smooth, or the relevant valves are not opened or not fully opened, and the solenoid valve fails, etc.
There is insufficient refrigerant.
There is a fault in the internal structure of the compressor.

III. Common Causes and Analysis of Severe Frost Formation on the Evaporator:

The air volume of the evaporator fan is insufficient, resulting in poor heat exchange.
The evaporator is too dirty, which affects the heat exchange of the evaporator.
Too much refrigerant enters the evaporator, leading to insufficient heat exchange.
The working condition temperature is too low and the humidity is too high.

IV. Common Causes and Analysis of Excessively High Suction Temperature of the Compressor:

There is insufficient refrigerant, and the refrigerant has already become overheated in the evaporator.
The expansion valve or the pipeline is blocked, resulting in insufficient refrigerant in the evaporator.
The opening degree of the expansion valve is too small or the throttling mechanism fails.
The suction pipe is too long or the thermal insulation of the suction pipe is poor.

V. How to Judge the Refrigerant Charge Amount

Weighing Method: The most accurate and scientific way is the weighing method. Just charge the refrigerant according to the indicated charge amount on the nameplate of the refrigeration equipment by weighing.
Besides the "Weighing Method", there are also commonly used methods for judging the charge amount, such as:
Sight Glass Method,
Ammeter Method,
Pressure Gauge Method,
Return Gas Superheat Method.