Location and replacement of the start-protection relay in Atlant refrigerators

A sudden stop in the operation of a refrigeration unit always takes you by surprise, especially when food supplies in the chamber begin to melt. Owners of equipment from the Belarusian brand Atlant often encounter a situation where the compressor hums, but no cold is generated, or the motor is completely silent. In most cases, the cause of the breakdown is the failure of the starting relay, which is responsible for starting the engine and protecting against overloads.

This small but critical element is located directly on the compressor housing, hidden by a plastic casing at the back of the unit. Understanding where is the relay on the Atlant refrigeratorallows you to quickly diagnose the problem and, with minimal skills, fix the problem yourself. However, before starting any work, it is necessary to clearly understand the design of the unit and follow the electrical safety rules.

In this article we will analyze in detail the design of the start-up protection device, the algorithm for finding and dismantling it, as well as methods for testing its functionality. You will learn how to distinguish a burnt-out relay from other breakdowns and what nuances should be taken into account when replacing a part in models with one or two compressors.

Purpose and principle of operation of a start-protection relay

The start relay in refrigerators Atlant performs the function of an automatic switch of electric motor windings compressor. When the refrigerator is turned on, the motor rotor is motionless, and a significant starting current is required to spin it up. The relay supplies voltage to the starting winding, creating the necessary torque.

As soon as the motor shaft picks up speed (usually this takes a fraction of a second), the current in the circuit drops, and the relay mechanism opens the contacts of the starting winding. The engine continues to operate on the main working winding. In parallel with the starting function, the device acts as a thermal protection: if the current exceeds the norm or the compressor housing overheats, the bimetallic plate opens the circuit, preventing the motor from burning out.

Modern models can use different types of relays, and understanding their differences is important for correct diagnosis:

• 🔹 Induction (electromagnetic): the classic version, where the contacts are closed under the action of the magnetic field of the coil at a high starting current.
• 🔹 Posistor (thermal): more modern devices, where the role of a switch is played by a ceramic element (posistor), which changes resistance when heated.
• 🔹 Combined: combine in one case there are both starting and thermal relays, which is typical for most models Atlant.

⚠️ Attention: Using a relay of the wrong type or with incorrect response current characteristics can lead to instantaneous burnout of the compressor windings. Always select an analogue strictly according to the markings of the original.

The service life of this component is limited, since the mechanical contacts burn out over time, and the bimetallic plates lose their properties. Frequent voltage drops in the network significantly accelerate the wear of the element, making it the first victim of an unstable power supply.

The exact location of the relay on the compressor body

To find the relay, you do not need to disassemble the entire refrigerator. All necessary elements are located in the lower rear part of the unit. You will need to move the refrigerator away from the wall to allow access to the back panel. On models Atlant the compressor is usually closed with a metal or plastic casing, which is secured with latches or screws.

After removing the casing, a black cylindrical or pear-shaped tank will be revealed to your view - this is the compressor. Directly on its terminals (shaft ends), which stick out from the side or bottom, the desired device is fixed. It is a plastic box of black or white color, placed directly on the motor contacts.

Depending on the modification of the refrigerator, the mounting design may differ:

• 🔸 Hard landing: the relay is simply put on the pins of the compressor and is fixed due to its tight fit and weight.
• 🔸 Latch: Some models are equipped with a metal bracket or a plastic clip that needs to be bent.
• 🔸 Terminal block: In rare cases, the relay can be placed in a separate terminal box next to the compressor, but this is rather an exception for older industrial models.

It is important to note that several wires are suitable for the relay, which come from the thermostat and the capacitor. They are connected via a connector or directly crimped into the contacts. In two-compressor Atlant models, the procedure is repeated for each motor separately, since each has its own starting device.

Dismantling algorithm and visual diagnostics

Before proceeding with the removal of the element, it is necessary to completely de-energize the refrigerator. Unplug the cord from the outlet and make sure there is no voltage at the terminals. Only then can the compressor protective casing be removed. Be careful: there are copper tubes of the refrigeration circuit running around the compressor, which can easily be damaged with a sharp tool.

The process of dismantling the relay is as follows:

1. Take a photo of the wire connection diagram so as not to mix up the contacts during assembly.
2. If there is a fixing bracket, carefully bend it flat screwdriver.
3. Remove the relay from the compressor terminals. It can fit tightly, so a slight rocking from side to side is allowed, but without sudden jerks.
4. Disconnect the wires going to the relay. In some models they are inserted into sockets, in others they can be soldered (which requires soldering when replacing).

After removing the device, conduct a visual inspection of it. The housing must not have any traces of melting, soot or cracks. If the plastic has turned black or deformed, this is a sure sign that a short circuit or severe overheating has occurred inside.

You can often hear inside the plastic case rattling if you shake the part. This means that the internal contacts are damaged or the mechanism is jammed. However, the absence of external defects does not guarantee serviceability, so a more in-depth check is necessary.

Checking the relay with a multimeter and performance test

For accurate diagnostics, you will need a multimeter (tester) set to resistance measurement mode (Ohms). The test is carried out in several stages to identify an open circuit or stuck contacts. First, inspect the contact groups for the presence of oxides or carbon deposits.

Next follow the diagnostic instructions:

1. Determine the type of your relay (posistor or induction) by markings or appearance.
2. For positor relay: measure the resistance between the contacts. It should be between 10–50 ohms. If the device shows infinity (open circuit) or zero (short circuit), the part is faulty.
3. For induction relay: ring the circuit between the contacts. In the initial position the circuit may be open. When current is supplied (in the assembled circuit), the contacts must close.
4. Check the thermal relay: in a cold state, the circuit should ring (resistance is close to zero). When heated (you can gently heat it with a hairdryer), the circuit should open.

There is a popular test method that requires extreme caution. You can try to start the compressor without a relay by briefly applying current to the starting winding, but this method is dangerous for beginners and can lead to electric shock or damage to the motor. It is more reliable to use a multimeter.

⚠️ Attention: If, after replacing the relay, the refrigerator does not start again, and the compressor hums and immediately turns off, the piston mechanism of the motor itself may have jammed or a breakdown of the windings has occurred. Further attempts to turn on may finish off the unit.

It is also worth checking the capacitor, which is often paired with a relay. Swelling of the housing or loss of capacitance of the capacitor can lead to a false diagnosis of a relay malfunction.

Atlant relay compatibility and marking table

When purchasing a new part, it is important to know the exact markings. The manufacturer Atlant uses various components depending on the year of manufacture and model of the refrigerator. Below is a table of common types of relays and their analogues that can be found on sale.

Please note that the marking RTK indicates a relay with copper coil mechanism, and the abbreviation PTC denotes a ceramic posistor. They are not always interchangeable without changing the connection diagram, so check the instructions for the specific refrigerator model.

Can a universal relay be used?

Universal relays (for example, Supertech) often have a set of adapters included. They are suitable for most compressors, but require careful selection of pins to match the terminals of your motor. The main thing is the coincidence in response current.

If you have not found an exact analogue in stores in your city, you can always order an original spare part using the catalog number indicated on the old relay. This guarantees full compatibility and long service life.

Replacing the relay and starting the refrigerator

The process of installing a new relay is the reverse of the dismantling process. Make sure that the new device fully matches the removed one in appearance and number of contacts. The orientation of the relay matters: there are usually marks on the body UP (top) or an arrow indicating the correct position.

Installation procedure:

• 🔹 Install the thermal relay (if it is separate) on the compressor terminals.
• 🔹 Place the starting relay on the pins until it stops. It should fit tightly and not dangle.
• 🔹 Connect the wires according to the previously taken photo or diagram. Typically, the blue and black wires go to the starting wire, the brown wire to the thermal wire, but colors may vary.
• 🔹 Reinstall the capacitor if it was removed.
• 🔹 Secure the retaining bracket or clamp.

After successful startup, you can install the protective cover and move the refrigerator to the wall. Be sure to leave some clearance for rear wall ventilation to prevent the compressor from overheating in the future. The entire replacement process takes an experienced technician no more than 20-30 minutes.

⚠️ Attention: If after replacing the relay the compressor works, but does not cool (does not freeze), the problem may be a freon leak or a clogged capillary tube. The relay only ensures the operation of the motor, but not the circulation of the refrigerant.

Common mistakes during self-repair

Home craftsmen often make typical mistakes that can lead to repeated breakdowns. One of the most common is ignoring the condition of the capacitor. The old capacitor may not provide enough starting impulse, causing the new relay to overload and quickly fail.

Another error is incorrect relay orientation. Some models only work in a certain position (for example, coil up). If you install the relay upside down, gravity will not allow the contacts to close or open correctly, which will lead to a buzzing sound and disabling the protection.

Also, do not neglect cleaning the condenser grilles on the back of the refrigerator. Radiator dust causes the compressor to work longer and heat up more, which shortens the life of not only the relay, but also the motor itself. Regular maintenance extends the life of equipment Atlant for years.

Questions and answers (FAQ)

Can a burnt relay be repaired or just replaced?

Theoretically, if only a posistor burns out, it can be replaced by selecting one with a similar resistance. However, in the context of household repairs, it is cheaper and more reliable to buy a new relay assembly. Restoring the contacts of the starting relay is also possible, but requires skills and does not guarantee long service life.

Why does the relay click, but the refrigerator does not turn on?

Clicks indicate that the thermal protection is triggered, opening the circuit. This occurs if the compressor tries to start but cannot (is stuck) or if the start relay does not open the start winding, causing an overload. Also, the reason may be low voltage in the network.

How much does it cost to replace a relay in a service center?

The cost consists of the price of the spare part itself (usually from 500 to 1500 rubles) and the work of the technician. At a service center, a replacement can cost 2000–3500 rubles, depending on the region and model of the refrigerator. Self-replacement saves the cost of work.

How often do you need to change the relay in the Atlant refrigerator?

The service life of the relay is not strictly regulated and depends on the quality of electricity and the frequency of switching on. On average, a high-quality relay lasts 5–10 years. Frequent replacements (once a year) indicate problems with the electrical wiring or the compressor itself.