How to turn on the refrigerator compressor: step-by-step instructions

The situation when refrigerator stops cooling, and the engine is silent, often taking you by surprise. In most cases, the reason lies in the failure of the starting relay, breakage of the windings, or problems with the thermostat. However, before calling a technician, it is worth carrying out basic diagnostics to understand whether it is possible to start unit on your own or whether a complex replacement is required.

It is important to understand that forced starting of the motor is only a test measure to identify malfunctions. Continuous operation of a refrigerator with a bypass circuit (bypassing standard protection systems) is unacceptable and can lead to complete combustion electric motor. In this article we will look at safe methods for checking and starting compressor for diagnostics.

⚠️ Attention: Carry out all work on checking the electrical circuits of the refrigerator only when the power is disconnected from the mains. Touching live parts under voltage is deadly.

Primary diagnostics before starting

Before disassembling the back panel and getting to the “heart” of the refrigerator, it is necessary to exclude external factors. Often motor it does not start due to a banal lack of power in the outlet or a malfunction of the control electronics. Check the voltage in the network, as surges could damage control board.

Carefully inspect the wiring for melting, especially in the contact area. If there are no visual defects, listen to the sounds: a humming sound without starting indicates a jammed piston group or a faulty trigger mechanism, and complete silence indicates an open circuit or a burnt out winding.

For accurate diagnosis, you will need a multimeter. With its help, you can ring the windings for a short circuit or break. Normal resistance between the contacts is usually from 10 to 30 Ohms, depending on the engine model.

• 🔌 Check the integrity of the power cord and plug.
• 🔊 Listen to the characteristic clicks relay.
• 🌡️ Make sure that the thermostat has not turned off the current supply due to low temperature.

Checking and replacing the starting relay

The most common cause of startup failure is a faulty starting relay. This small unit is responsible for supplying an impulse to the starting winding compressor. If the relay is stuck or burnt out, the engine will not receive the necessary push to start rotating the shaft.

Remove the relay from the compressor contacts and shake it. If a knock is heard inside, it means that the mechanism or contacts are damaged and the part requires replacement. Also inspect the inside for carbon deposits or melting of the plastic - this is a sure sign of a short circuit. Installing a new relay occurs in the reverse order: it is important to correctly orient the part according to the marking (usually the arrow points up). After replacing, try turning on the refrigerator - if short circuit.

Installing a new relay occurs in the reverse order: it is important to correctly orient the part according to the markings (usually the arrow points up). After replacing, try turning on the refrigerator - if motor works smoothly, the problem is solved.

In some models of refrigerators, especially old Soviet or industrial ones, a starting capacitor may be used. Its malfunction also makes it impossible to start, although a hum may be present.

⚠️ Attention: The starting relay is selected strictly for the compressor model. Installing an unsuitable relay can lead to overheating of the windings and a fire.

Direct connection of the compressor (Testing method)

To check the functionality of the compressor itself motor, bypassing the refrigerator control system, you can use the direct connection method. This allows you to understand whether motoris alive, or whether the problem lies deeper in the system. The essence of the method is to apply voltage directly to the working and starting windings.

You will need a piece of wire with a plug and a button (or toggle switch) to break the circuit. The connection diagram is simple: one wire goes to the common contact, the second to the working winding, and the starting winding is closed through the button only at the moment of start. Be prepared for the fact that the shaft can jerk with great force.

Connection diagram:
Phase (L) -> Button -> Start winding (S)
Phase (L) -> Working winding (R)
Zero (N) -> Common contact (C)

After starting the engine, the button on the starting winding must be released (or it will turn off itself if a starting relay is used). If the unit picks up speed and runs smoothly, then the problem is in the electronics of the refrigerator, and not in the motor.

Sometimes the compressor itself is working, but does not receive a command to turn on. A thermostat (thermostat) or an electronic control module is responsible for this. If the temperature sensor “freezes” and shows that it is cold in the chamber, the power circuit the motor will not close.

In mechanical refrigerators, you can close the thermostat contacts directly (using a jumper) to check whether the system will start. In modern models with electronics, the cause may be a faulty defrost sensor or air sensor. Pay attention to the indication: if error codes are displayed on the display, diagnostics begins with their decoding. Often the problem lies not in the mechanics, but in the “brains” No Frost and electronically, the cause could be a faulty defrost sensor or air sensor.

If the diagnostics showed a break in the windings, a breakdown in the housing or wedge of the piston group, the only solution is to replace the compressor. This is a complex procedure that requires a vacuum pump, a torch and skills in working with the refrigeration circuit.