Appliance stopped turning on and working? First of all, diagnose the motor – this part is called the “heart”. How to check the refrigerator compressor? If you do not want to contact the service center and pay the master, we will tell you how to do the work yourself.
The principle of operation and the device of the motor
The operation of a refrigerator of any model (Atlant, Indesit, Stinol) is generally the same. It is based on the circulation of the refrigerant (freon) in the system. Initially, the refrigerant is a gas, the pressure that the compressor creates contributes to its entry into the condenser. There, the gas cools, turns into a liquid and flows into the evaporator. When heated, the liquid goes into the primary state and repeats the cycle.
Therefore, if there is a problem with the compressor, it will not create pressure or it will not be enough for normal operation.
The degree of cooling – the temperature in the chamber – is regulated by a thermostat. From it, the signal goes to the motor start relay, which starts the whole process.
The motor-compressor is located on the rear side of the unit housing. It is fixed in special oil and covered with a protective cover, which you can see in the picture.
The electric motor consists of a starting and working winding, as well as a relay.
Three outputs are connected to the case, one of which is common. The other two lead to the starting and working winding. In the latest models of refrigerators, an electrical circuit is installed that can regulate the speed of the engine.
Functional Testing
Why does the compressor stop working?
- Burned out. This happens as a result of a sharp power surge and increased load.
- The start relay is broken.
- Defective wiring.
It happens that the device buzzes and works, but there is no cold in the cells. The reason may be the release of freon gas. Then it is better to contact a specialist who will detect a leak and refuel the system.
To find out if the device is working or not, use a multimeter. Once you get to the motor, you need to make sure that the case does not break through, otherwise it can shock. Most often this happens in old refrigerators. Attach the multimeter probes to the case and each contact in turn. If the display shows “∞”, then everything is in order. If numbers appear on the display, the winding is faulty.
To perform further diagnostics, you need to dismantle the casing and open access to the compressor. For this:
- Disconnect wiring from contacts.
- Snip the motor tubes that connect it to other parts.
Important! Before starting work, find out what type of refrigerant is used in your refrigerator. This gas can be explosive.
- Unscrew the fixing bolts of the casing and remove from the casing.
- Disconnect the relay by unscrewing the screws.
- Now take a tester and measure the resistance between the contacts.
- Attach the probes to the right and left output pins. Normally, the resistance will be 30 ohms. The top right will show 15 ohms and the top left will show 20 ohms.
Depending on the engine model and the refrigerator itself, the values may differ by ± 5 ohms.
- If the readings do not match, the device is defective. If a break appears somewhere, a conventional or inverter motor must be replaced or repaired.
The compressor passed the test, but the equipment does not work? So, proceed to further tests, but not with a tester, but with a pressure gauge.
- You need to measure the pressure.
- Connect a hose with a branch to the discharge fitting.
- Start the engine.
- Measure pressure.
- Indications for a serviceable device should be 6 atm and increase. In this case, you need to quickly turn off the pressure gauge, otherwise it will break.
- If the pressure does not reach 6 atm a little, such an engine can be installed in medium-sized refrigerators. The readings reach 4-5 atm, which means that the motor can be used in single-chamber refrigerators. A compressor with a pressure of less than 4 atm is inoperative.
The health check passed, but no result. The unit still does not turn on. In this case, you can establish the performance of the motor by connecting directly, without a starting relay.
Important! Such work is life-threatening. Such a diagnosis can be carried out either by a master or an experienced person.
Connect the motor through the cord according to the diagram:
In extreme cases, you can check whether the motor is running through a relay. Perhaps the current does not reach the device.
- Prior to this, diagnostics were carried out without a relay, now connect it to the motor.
- Perform a launch.
- Arm yourself with a tong tester.
- Press the pliers on the mains cable that leads to the device.
- Look at the indicators: at a power of 140 W, the current should be 1,3 A. At a power of 120 V – 1,1–1,2 A.
Additionally, diagnose the start relay. Its contacts are also measured with a multimeter.
Now you know how to check the motor-compressor with your own hands. For persuasiveness, watch the video about the diagnosis: