How Do You Know If Your Refrigerator Compressor is Bad?

Figure 1: LG compressor.

The compressor is the heart and core component of the refrigerator. If the compressor doesn't work, the entire refrigerator won't function. So what are the symptoms of a broken compressor and how can you determine if the compressor is faulty?

Note that what may appear to be a compressor failure may not actually be a compressor failure, so it's important to first eliminate the possibility of the faults caused by other components before confirming it is a compressor failure. Then, take corresponding measures such as replacing the corresponding parts or replacing the compressor.

1. Symptoms of a Broken Refrigerator Compressor

If the refrigerator compressor is damaged, the refrigeration function of the refrigerator will be greatly affected. When the refrigerator stops working, leaks or makes a lot of noise, it can be determined that there may be a problem with the refrigerator compressor.

We can determine whether there is a bad refrigerator compressor from the following symptoms: abnormal noise, abnormal temperature, or frequent on/off cycling.

1.1 Abnormal Noise

When the refrigerator is running, if you hear loud noises from the compressor at the back of the refrigerator, there may be a problem with something inside the compressor and the compressor needs to be repaired or replaced.

1.2 Abnormal Temperature

After the refrigerator has been running for a period of time, you can touch the refrigerator compressor by hand to feel the temperature. If the temperature of the refrigerator compressor is very high, it indicates that the refrigerator compressor has malfunctioned with other mechanical components.

In addition, if you find that the temperature inside the refrigerator is not low enough and the shelf life of food is shorter than usual, this may indicate that the refrigerator compressor has a problem and is unable to circulate the refrigerant into the cooling pipes, resulting in poor refrigeration performance.

1.3 Frequent on/off Cycling

If you find that the refrigerator is turning on and off frequently, or if it takes a long time to restart, this may indicate that there is a problem with the refrigerator compressor.

2. How to Check If the Refrigerator Compressor is Damaged?

First, check if the compressor is connected to the power supply. If the compressor does not start, it can generally be seen from the power circuit, such as power failure, poor switch contact, blown fuse, etc. If these phenomena are found, they should be analyzed comprehensively to find the root cause and eliminate it.

Figure 2: Refrigerator working circuit diagram.

2.1 First Exclude Power Supply, Voltage and Compressor Accessory Problems

(1) Check if there is electricity in the input power circuit, which can generally be determined by using a multimeter or a test pen. If the fuse is found to be blown, find out the cause and replace it with a new one according to the specification.

(2) Check the compressor accessories, including thermal protection and relays. If the thermal protection is damaged, the compressor cannot be powered on. If the relay does not work, it generally indicates that the motor does not rotate after the compressor is powered on, and there will be a "humming" noise. In this case, stop the machine immediately, otherwise the motor winding may be burned out if it is left running for too long.

Figure 3: Refrigerator compressor and components.

(3) Check if the circuit voltage is normal. If the circuit voltage is significantly lower than the rated value, the motor is not easy to start and emits a "buzzing" sound. Use a voltmeter to measure the voltage. If the voltage is low, you need to purchase a voltage regulator to increase the voltage value for operation.

(4) To check whether the thermostat is normal, you can put the temperature sensing plate into warm water to test.

For refrigerators that have not been used for a long time, if the refrigeration effect deteriorates or it cannot run normally after being used for a period of time, it may be due to a decrease in the capacity of the capacitor. (Note: In general, the decrease in the capacity of the capacitor gradually reduces with time.)

After troubleshooting by the above methods, check if the compressor is faulty. The following are some methods for troubleshooting compressor faults.

2.2 How to Check If the Compressor is Faulty

1.Judging Compressor Faults by Sound

When the compressor is running, listen carefully to the sound it emits. Based on the sound, the working state or performance of the compressor can be roughly determined. Please refer to the following phenomena for specific judgment methods.

● A relatively small "buzzing" sound: the mechanical components of the compressor are normal.
● No "buzzing" sound can be heard: the compressor is damaged or its power supply circuit has problems.
● Strong "buzzing" sound: The compressor does not start when it is powered on, mostly due to cylinder sticking or shaft holding.
● A "tong-tong" sound: a large amount of refrigerant wet vapor or refrigeration oil enters the cylinder.
● A "dang-dang" sound: loose internal moving parts.
● A "hissing" sound: the high-pressure pipe inside the compressor ruptures and emits a high-pressure airflow sound.

If the running sound of the compressor is abnormal, except for cylinder sticking or shaft holding, which maybe can be repaired through some methods, other faults can only be repaired by replacing the compressor.

2.Testing the Winding Resistance of the Compressor

Figure 4: Test the refrigerator compressor components.

If the compressor cannot start and work, the resistance value of the compressor motor winding needs to be checked with a multimeter to determine whether the compressor motor has a fault.

Connect the red and black test leads of the multimeter to any two winding ends of the compressor, and measure the resistance value between the compressor windings. Normally, the resistance value between the start terminal and the run terminal is equal to the sum of the resistance values between the common terminal and the start terminal and between the common terminal and the run terminal.

The above is the testing and judgment method of the motor winding of the fixed frequency compressor in the electric refrigerator while the three resistance values of the inverter refrigerator compressor are completely the same.

Figure 5: Motor winding resistance measurement of fixed-speed and inverter compressors.

3.Testing the Insulation Resistance of the Compressor

In addition to the above method for testing the compressor, the good or bad of the compressor can also be judged by measuring the insulation resistance of the compressor motor.

Under normal circumstances, the resistance value between the compressor motor winding and the compressor shell should be infinite. If a small resistance value is measured, it indicates that the motor winding inside the compressor is short-circuited with the shell, which may not only cause compressor faults but also lead to electric leakage. The insulation should be restored in time or the compressor should be replaced directly.

If there is no insulation resistance tester available for actual testing, a multimeter can also be used to test the insulation resistance of the compressor and roughly determine whether the motor winding of the compressor is short-circuited with the shell.

3. Preventing Compressor Failure

Of course, the best way to avoid a failing compressor is to prevent it from happening in the first place. Here are some tips to help you keep your compressor running smoothly.

3.1 Keep Your Refrigerator Clean

Regularly cleaning your refrigerator can help prevent compressor failure. Make sure to clean the condenser coils at least once a year, and keep the area around the fridge free of dust and debris.

Figure 6: Clean the refrigerator.

3.2 Don't Overload Your Fridge

Overloading your refrigerator can put a strain on the compressor, causing it to work harder than it needs to. Make sure to leave some space around your food and drinks to allow for proper air circulation.

3.3 Use Your Refrigerator Properly

Using your refrigerator properly can also help prevent compressor failure. Make sure to keep the temperature set at the recommended level, and avoid opening the door too often or for too long.

Actually, a refrigerator compressor is not easily damaged. The lifespan of a typical refrigerator is around 10 years. If the refrigerator has been used for more than 10 years and the compressor is damaged, it is recommended that you replace the refrigerator instead of continuing to use the old one because older refrigerators consume more electricity.

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