Fault analysis: When the motor winding burns out or turns are short-circuited, the fuse is often blown repeatedly, especially when the knife switch is pushed up.

Exclusion method:? Check whether the terminal is short-circuited with the shell and the resistance of each phase with a multimeter. If there is a short circuit or the resistance of a certain phase is small, it means that the winding and turn are short-circuited and the insulation is burnt out. During inspection, the insulation resistance can also be measured by megger. If the resistance is lower than 2mω. If the press is burnt out, it can be replaced. It means that the insulation layer has been broken down. If the press is burnt out, it can be replaced.

2, control relay failure

Fault analysis is generally prone to contact overheating, burning and wear, which will make poor contact. Troubleshooting: Remove, repair or replace with a new one.

3. The temperature controller has poor contact.

Fault analysis usually includes contact burn or temperature sensitive agent leakage.

The new elimination method replaced the elimination method.

4. Check whether the connector falls off or is disconnected, and check whether there is any abnormality in other electrical aspects.

5, compressor mechanical failure

A, shaft locking: mostly due to insufficient lubricating oil, the oil circuit of the lubricating system is blocked or the oil supply is interrupted, and the dirt and impurities in the lubricating oil increase the viscosity, which will lead to shaft locking. Copper plating can also cause shaft sticking.

B. Cylinder sticking: due to the small fit clearance between piston and cylinder, or the thermal expansion relationship, it is stuck.

Judgment of shaft-holding and cylinder-sticking: After the refrigerator is powered on, the compressor does not start running, but you can hear a slight buzz when you listen carefully. After a few seconds, the thermal protection starter acts and the contact is disconnected. Even if this action is repeated, the compressor will not start.

Extended data

The specifications of compressors are classified according to input power. Generally, the difference between each specification is about 50W. In addition, there is the cylinder volume.

Input and output power, performance coefficient, refrigeration capacity, starting current, working current, rated voltage, frequency, cylinder volume, noise, etc. To measure the performance of a compressor, we mainly compare it from three aspects: weight, efficiency and noise.

According to the national standard, the safety performance test was carried out according to the project specified in GB4706. 17-2004. The main items are electrical strength, leakage current, locked rotor and overload operation test.

The performance test of air-conditioning compressor is carried out according to GB5773-2004.

In addition, when there are major changes that may affect the product performance during product finalization and production, when the product has been continuously produced for more than one year, and when the factory inspection results are quite different from the type test, the type test must be carried out.

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