WHAT SHOULD BE CHECKED IN A REFRIGERATOR WITH A MECHANICAL THERMOSTAT?
Let’s first consider an ordinary refrigerator with a mechanical thermostat. If we do not talk about the problem of wires and bad contacts, then there are only three main reasons for not starting the compressor:
– thermostat malfunction;
– malfunction of the starting relay;
– compressor malfunction.
From which element to start the check does not really matter. Let’s see what is easier and more accessible for disassembly. If furniture interferes with pulling out and unfolding the refrigerator, and besides, it is heavy, we start diagnostics by checking the thermostat. In one of our articles, we have already written about how to check and replace the thermostat yourself.
We will not go deeper, just recall: with the device turned off, remove the covers, shades, and everything that covers the thermostat. Short the wires that go to the thermostat contacts with each other, except for the ground wire (it is usually green with a yellow stripe). Please note that if the thermostat is located in the lighting plafond, the blue power wire also comes there. We also do not use it. If the thermostat is connected through the contact block, use a jumper on the brown and black wires.
Turn on the refrigerator to the network. If the refrigerator compressor starts, change the thermostat to a new one. If the start did not occur, check the start relay.
FEATURES OF CHECKING WITH AN ELECTRONIC THERMOSTAT
If you own a refrigerator with a beautiful display on the door, and the motor is silent, of course, this is a cause for concern, but do not panic.
Refrigerators of a static freezing system or otherwise – “drip” or “weeping”, as well as No Frost systems can be controlled by an electronic thermostat or a whole module. Such a check requires special knowledge, skills, and equipment. It is best to leave it to a specialist. You can check the presence of defective elements that have burned out on the board, the integrity of the wiring loop, and the quality of contacts in the connectors. Let me remind you that we check this on a de-energized device. I will suggest one more point. Some electronically controlled refrigerators have a delay when turned on. It may take several minutes from the moment of plugging into the start of the engine. During this time, the device can test its components. Some of them start and stop the compressor during the test to put it back into operation no earlier than five minutes later. If the refrigerator is plugged in, the display works as usual (in some cases, an error code may be displayed), enough time has passed, and the compressor does not start, check the starting relay.
CHECKING THE COMPRESSOR STARTING RELAY
To check the compressor start relay, you will need to move the refrigerator. Organize access to the engine compartment. In some refrigerators, the compressor is closed with a special partition.
Especially if the device system implies the presence of a subcondenser cooled by a fan. At the same time, you can clean the engine compartment of accumulated debris. Usually, there is a starting relay to the left of the compressor.
It together with the contact group is closed by a box. Some manufacturers in the form of a picture on such a box indicate its removal sequence.
We get to the relay itself. Check the quality of connections and contacts. Having found nothing, remove the starting relay from the compressor contacts. For further checking, we will need a multimeter. It is worth immediately measuring the resistance of the compressor windings.
If there are no breaks or short-circuited turns, check the relay itself. Changing the color of the plastic, many users take for the burnout of the elements of the starting relay. Let’s not rush to conclusions, let’s do it correctly. If the starting relay consists of thermal protection and a posistor, we check them one by one. Different relays are used for different engines.
But most often the resistance of the posistor in the cooled state is in the range of 18-50 Ohms. Thermal protection should have a minimum resistance.
Some compressors, such as Danfoss, have thermal protection built inside the motor. In this case, we check only the resistance of the posistor or as people say “pills”.
HOW TO CHECK A REFRIGERATOR WITH AN INVERTER COMPRESSOR?
If your refrigerator is equipped with an inverter compressor, and this can be indicated on the device itself, then in the box where the starting relay is usually located, you can find only a terminal block.
In this case, all you can check is the resistance of the compressor windings. Usually, they have a value from 9 to 20 ohms and are the same between different contacts. But it is better to immediately entrust the check of such refrigerators to specialists. Moreover, your neighbor, who has twenty years of experience as an electrician, is unlikely to be able to help you professionally.
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Our service center is open 24/7, so you can easily schedule a convenient repair time. The specialist will arrive at the agreed time, carry out a diagnosis, and, if necessary, offer repairs. If you are willing, your appliance will be repaired directly on-site within 1-2 hours. We provide top-notch service at an affordable price!