Sudden stoppage of the refrigerator Atlant often becomes an unpleasant surprise, especially when food in the chamber begins to deteriorate. One of the most common culprits in this situation is the failure of the start-up relay, which is responsible for starting the compressor and protecting the engine from overloads. If you hear the engine trying to start, making a click and immediately stopping, or the compressor hums but does not start, the problem most likely lies in this unit.
Before calling a technician or buying a new part, it is necessary to carry out proper diagnostics. Checking the Atlant refrigerator relay with a multimeter is this a procedure accessible to any home handyman who has basic skills in working with electrical appliances and a simple measuring tool. Accurate diagnostics will allow you to avoid unnecessary expenses on replacing serviceable parts and make sure that repairs are necessary.
In this article we will analyze in detail the algorithm of actions necessary for the safe removal and testing of the component. You will learn how to properly set up a measuring device, which indicators are considered normal, and which indicate a breakdown. We will also look at the differences between thermal and posistor relays, since both types can be found in refrigerators Atlant depending on the model and year of manufacture.
The operating principle and types of relays in Atlant refrigerators
The starting relay in refrigerators Atlant performs the function of an electrical a switch that supplies voltage to the compressor starting winding only at the moment of startup. As soon as the engine reaches the required speed, the relay opens the starting winding circuit, and the motor continues to operate on the main winding. In parallel with this, thermal protection is often built-in, turning off the power in case of critical overheating or overcurrent.
In household appliances of the Belarusian manufacturer, two main types of devices are most often found. The first type is posistor relays, which work due to the property of a ceramic element (posistor) to sharply increase resistance when heated. The second type is electromagnetic or induction relays, where the circuit opens under the influence of current flowing through the coil and the lowering of the core.
- 🔹 Posistor relays are considered more modern, do not have moving mechanical parts inside and are characterized by increased reliability.
- 🔹 Electromagnetic devices contain a movable core and contacts, which can burn or stick over time, requiring cleaning or replacement.
- 🔹 Thermal protection in both cases can be integrated into the relay housing or made in the form of a separate tablet placed on the compressor contacts.
Understanding the type of device installed important for correct interpretation of test results. If in an electromagnetic relay it is possible to visually assess the state of the contacts by opening the case, then the posistor element requires mandatory ringing with a tester, since external signs of a malfunction may be absent.
Preparation for diagnostics and safety measures
Any work related to the electrical components of the refrigerator requires strict adherence to safety precautions. The first and most important step is to completely unplug the unit Unplug the plug from the socket and make sure that access to the back of the refrigerator is clear. You should not rely only on the temperature regulator - physical disconnection from the network is necessary.
⚠️ Attention: Before starting work, make sure that the capacitor (if your model has one) is discharged and your hands are dry. Working with electricity, even at low voltage, requires caution to avoid electric shock or short circuit.
You will need a set of tools to carry out diagnostics. The main device will be multimeter (tester), which can be purchased at any electrical goods store. You will also need a Phillips and flat-head screwdriver to remove the protective cover of the compressor and fix the relay, as well as pliers to carefully remove the terminals.
Ensure good lighting of the work area, since the back wall of the refrigerator is often located in a darkened corner. If the refrigerator is close to the wall, move it away to allow easy access from all sides. This will not only make the work easier, but will also protect you from accidental damage to other components.
☑️ Preparation for checking the relay
Removing the start relay from the compressor
After all precautions have been taken, you can begin dismantling. Remove the rear protective cover of the compressor compartment. It is usually secured with latches or a few screws. Under the cover you will see a black cylindrical or square compressor housing, to the bottom of which the desired device is attached.
The relay is placed directly on the contact pins of the compressor and is often additionally secured with a metal bracket or strip. Carefully bend the clamp or unscrew the fastening screws. It is important not to use excessive force so as not to damage the fragile contacts or the part body itself.
Remove the relay from the pins. It can fit tightly, so slight rocking from side to side is allowed. Disconnect the wires going to the relay. To do this, you may need to remove the insulating tape or simply unclip the connectors, if provided by the design. Be sure to remember or take a photo of which wire was connected where so that you don’t mix up the polarity during assembly.
Visually inspect the removed part. The presence of melted plastic, soot, cracks or a characteristic burning smell almost always indicates a malfunction. However, even if the relay visually looks intact, this does not guarantee its serviceability, so the instrumental testing stage cannot be skipped.
Setting up the multimeter and testing method
To check the relay, you must switch the multimeter to resistance measurement mode (Ohm). Select the measurement range, usually a range of up to 2 kOhm or 20 kOhm, depending on the model of the device. If you have a digital tester, make sure that the battery in it is charged, since a dead battery can give distorted readings.
The test begins with calibrating the device itself. Connect the probes to each other - zeros or values close to zero should appear on the screen. This will confirm that the chain of probes is intact and the device is ready for use. Then start testing the relay contacts.
You need to test the circuit between the input and output contacts. In good condition (for an electromagnetic relay), the resistance should be minimal, close to zero, which indicates the integrity of the coil and contacts. If the device shows one or infinity, it means there is an open circuit.
Nuances of checking a posistor
The posistor at room temperature should have a low resistance (20-50 Ohms). If the multimeter immediately shows infinity, the element has burned out. If the resistance is high, the posistor has degraded and will not start the compressor.
Pay special attention to checking the thermal protection. Ring the contacts of the bimetallic strip. Resistance should tend to zero. If the tester shows an open circuit, it means that the protection worked earlier and did not return to its original state, or it is faulty. In this case, the relay must be replaced.
Analysis of readings and fault table
Measurement results may vary, and it is important to interpret them correctly. The numbers on the multimeter screen will tell you more about the internal condition of the part than an external inspection. Below is a table that helps decipher the received data for various relay states.
| Multimeter readings | Circuit condition | Probable cause | Action |
|---|---|---|---|
| 0.1 - 5.0 Ohm | Normal | The circuit is intact, the resistance is within acceptable limits | The relay is OK |
| Infinity (1) | Open | The winding burned out, the posistor or contacts burned out | Replacing the relay |
| 0 Ohm (constant) | Short circuit | Contact sticking or breakdown | Replacing the relay |
| Floats when heated | Instability | The operation of the posistor or bimetal is disrupted | Replacing the relay |
If you find an open circuit where there should be resistance, or vice versa - a short circuit, this is a clear signal to replace the component. Repairing burnt-out internal elements, especially posistors, is economically impractical and technically difficult.
It is worth noting that in some models Atlant the relay can be composite, where the thermal protection and the starting device are separated. In this case, check each part separately. A malfunction of one of them requires replacement of the entire assembly or the defective part if it is sold separately.
Frequent diagnostic errors and their consequences
One of the common mistakes is checking a relay that has not been removed from the compressor without disconnecting the wires. In this case, the multimeter may show the resistance of adjacent motor circuits, which will lead to a false conclusion about the serviceability of the relay. Always disconnect the relay from the general circuit to obtain accurate data.
Another mistake is ignoring the state of the contacts on the compressor itself. Even if the relay is working properly, oxidized or burnt contact pads on the motor pins may prevent normal starting. Before installing a new part, inspect and, if necessary, clean the compressor contacts with fine sandpaper.
- ❌ Trying to start the refrigerator with a shorted relay may lead to burnout of the compressor windings.
- ❌ Installing a relay from another model without checking the parameters may cause incorrect operation of the protection.
- ❌ Ignoring the wiring check may leave a hidden problem that will disable the new relay.
Also, do not forget about the possible sticking of contacts in electromagnetic relays. If you hear a knocking noise when you shake the relay, but there is contact when you test, this may mean that the contacts are stuck together. In this case, the relay may not open the starting winding, which will lead to overheating and humming of the motor.
⚠️ Attention: Do not try to repair the relay by stripping the contacts or gluing the case unless you have professional skills. Violation of tightness or changes in gaps can lead to a fire hazard.
Replacement of the relay and final check of the system
If diagnostics have confirmed a malfunction, you must purchase an analogue. For refrigerators Atlant it is important to select a relay with identical characteristics, since different compressor models require different starting power. The part number is usually indicated on the body of the old relay or in the technical documentation.
Installation of the new element is carried out in the reverse order of removal. Push the relay onto the compressor pins as far as it will go, making sure it is seated snugly and evenly. Connect the wires according to the photographs or color markings you took earlier. Secure the fixing bracket or bar.
After assembly, do not rush to load the products. Plug in the refrigerator and listen. The compressor should start with a characteristic hum, the relay should click once at startup. If the motor started running smoothly and after some time the cooling process began, the repair was successful.
If after replacing the relay the situation has not changed (the compressor hums, but does not start, or does not turn on at all), the problem may be deeper. This may indicate an interturn short in the motor windings, a jammed compressor, or a wiring fault. In such situations, further independent repairs can be dangerous, and it is better to contact specialists.
Regular maintenance of the refrigerator, including cleaning the condenser from dust and checking the seals, helps to extend the life of all components, including the start relay. Monitor the room temperature and do not place the refrigerator close to the wall to ensure normal ventilation.
Is it possible to check the relay without a multimeter?
Indirectly - yes. You can connect a working relay from another refrigerator (with similar parameters) and check the startup. However, this method does not provide a 100% guarantee and requires the presence of a donor part. Visual inspection for burning is also a verification method, but less accurate.
Why does a new relay burn out immediately after installation?
This can happen for several reasons: incorrect selection of the relay model, problems with the voltage in the network, jamming of the compressor or a short circuit in the wiring of the refrigerator. Also, the reason may be a factory defect of a new part.
What is the service life of the starting relay?
The average service life of a high-quality relay is 5-10 years. However, with frequent power surges or compressor overheating, this period can be significantly reduced. Posistor relays generally last longer than electromagnetic relays.
Does room temperature affect the operation of the relay?
Yes, indirectly. In a room that is too hot, the compressor works with increased load and overheats more often, which causes the thermal protection of the relay to trip more often. This accelerates the wear of the bimetallic plate and contacts.