The failure of refrigeration equipment often takes you by surprise, and the first sign of a malfunction is the unnatural hum of the motor or its complete silence when plugged into the network. In most cases, the cause of such symptoms is a failure start relay, which is responsible for starting the compressor engine. Understanding where exactly this node is located is a key step for self-diagnosis and possible repair of household appliances.
The location of this element depends on the design of the specific model and year of manufacture of the device, however, there are general principles of layout that are characteristic of most brands. Typically the relay is mounted directly on the compressor housing or in close proximity to it, often hidden by a protective casing. To access it, you do not need to disassemble the entire unit; it is enough to correctly determine the area of responsibility and carefully dismantle the protective panels.
It is important to understand that incorrect diagnosis can lead to more serious damage, so before starting any work you need to study the structure of your refrigerator. In this article we will analyze in detail the search algorithm, visual signs of a malfunction and nuances that will help you accurately determine the location of the starting mechanism in your model of equipment.
The design and role of the starting relay in the system
The starting relay is an electromechanical switch that supplies voltage to the starting winding of the engine only when it starts. As soon as the compressor rotor reaches the required speed, the relay opens the circuit and the engine continues to operate on the main winding. Without this element, starting a powerful motor would be impossible or would lead to its overheating and combustion.
Modern refrigerators most often use thermal relays or devices with a posistor, although in older models you can still find electromagnetic options. PTC models are considered more reliable, since they have no moving parts that could jam. However, they are also subject to wear, especially with frequent power surges in the network.
It is critically important to know that starting relay is often combined with a thermal release, which protects the compressor from overcurrent. This combination is called a start-up protection relay (PZR). If one of the components fails, the entire unit often needs to be replaced, since manufacturers rarely supply internal parts separately.
What is the difference between different types of relays?
Electromagnetic relays emit a characteristic click each time they start and have a movable core. PTCs operate silently (except for the moment the contacts close) and change their resistance depending on the temperature, which makes them more durable in unstable network conditions.
The location of this unit is always dictated by ease of maintenance and the need for heat removal. Engineers try to place the relay so that it does not heat up from a running compressor, but at the same time is accessible for replacement without completely disassembling the unit.
Typical locations in various models
The answer to the question of where the start relay is located lies in the design of the rear wall of the refrigerator. In the vast majority of cases (about 95% of models), access to the compressor and attachments is through the lower part of the rear panel. This is where the so-called engine compartment is located.
In some models, especially built-in or compact ones, the design may differ. Here the relay can be placed in a separate plastic box or mounted on the side wall of the compressor unit. In two-compressor systems, each motor has its own control unit, so you need to look for the relay for each compressor separately.
To accurately determine the installation location, you need to remove the protective cover, which is usually secured with latches or screws. Under it you will see a black metal compressor tank, and on the side or above it there will be a small box - this is the element you are looking for. Often wires coming from the thermostat or electronic control module come to it.
It is worth noting that in refrigerators with the No Frost system, access to the relay may be a little difficult due to the presence of an additional fan or air ducts, but fundamentally the search area remains the same - the lower rear part of the case.
Step-by-step instructions for accessing the relay
To get started work must be carried out safely. Disconnect the refrigerator from the electrical outlet by removing the plug from the outlet. This is a must because you will be working with electrical components that may be live even after being turned off if there are capacitors in the system.
Move the unit away from the wall to gain clear access to the rear wall. You will need some room to maneuver as you will have to bend over and possibly lie down on the floor. Make sure the floor is dry and clean to avoid damaging the finish or staining your clothing.
Remove the rear protective panel. It can be made of thin metal, cardboard or plastic. Fastenings can be different: screws, latches, or a combination of both. Act carefully so as not to break the fragile plastic fixings.
☑️ Preparing for access
After removing the panel, you will see a view of the compressor - a black metal cylinder. On its side (left or right, depending on the model) there will be a motor shaft protruding, covered with a plastic or metal casing. This is the place where the starting relay is located start relay.
Diagnostics and visual signs of a malfunction
Before proceeding with the replacement, you need to make sure that the problem lies in the relay. Often the symptoms of compressor and relay failure are similar, but the methods for eliminating them differ. A visual inspection can provide a lot of useful information.
If the refrigerator hums when turned on, but does not start, and after a few seconds there is a click and the buzzing stops, this is a classic sign of problems with the starter mechanism. It is also worth paying attention to the smell: if you smell burnt plastic or a chemical smell, this may indicate a burnt winding or a melted relay body.
Remove the relay from the compressor. It is usually held in place by latches or a spring clip. Carefully disconnect the wires (after photographing their location) and remove the part. Shake it near your ear: if something rattles inside, it means the mechanism is damaged and requires replacement.
⚠️ Attention: If the relay contacts show signs of severe corrosion, carbon deposits or plastic melting, further operation of the device without replacing the part is impossible and can lead to a fire.
Additionally, you can check the integrity posistor or coil using a multimeter, but this requires basic knowledge of electrical engineering. The resistance must correspond to the values stated in the technical documentation, usually several Ohms for the starting winding.
Compatibility and relay characteristics table
When looking for a replacement, it is important to consider not only the appearance, but also the technical characteristics. Different refrigerator models require relays with certain current parameters and compressor type. Below is a table with common types of relays and their parameters.
| Relay type | Applicability | Characteristic current | Features |
|---|---|---|---|
| RT (Electromagnetic) | Old models (Atlant, Biryusa) | 1.3 - 2.2 A | Sensitive to skew, require precise orientation |
| P-1 (Posistor) | Medium and new models | 1.4 - 1.8 A | Work in any position, less noisy |
| ROM (Universal) | Replacement of failed analogues | Adjustable | Require settings for a specific compressor |
| Denso (Danfoss) | Imported equipment | 1.6 - 2.5 A | High reliability, often assembled with thermal protection |
When selecting an analogue, be sure to check the markings on the body of the old part. Even if (appearance) is the same, different current characteristics may cause the new compressor to either not start or burn out due to lack of protection.
Replacement and installation of a new element
The replacement process is relatively simple, but requires care. After purchasing a suitable analogue, make sure that the new trigger mechanism matches the seats and connectors. If the connectors are different, they can be carefully replaced, observing the color coding of the wires.
Install a new relay on the compressor shaft. It should fit tightly and click. Make sure it is positioned correctly: the case often has an "UP" arrow or "This side up" to indicate the top position. Incorrect orientation may result in failure.
Connect the wires to the contact groups. Proceed strictly according to the diagram that you photographed during dismantling. An error in the connection can lead to a short circuit or operation of the compressor in the wrong mode, which is dangerous for the windings.
⚠️ Attention: Technical characteristics of compressors and requirements for relays may vary depending on the modification. Always check the data with the official documentation of the manufacturer of your specific refrigerator model before purchasing spare parts.
After assembly, do not rush to close the back panel. Plug in the refrigerator and listen. The compressor should start with a characteristic hum, the relay may click slightly at the moment of start, and then the operation should proceed smoothly and without extraneous sounds.
Common mistakes during self-repair
One of the most common mistakes is ignoring the cause of the relay failure. If the relay burns out, this is often the result of a power surge or problems with the compressor itself (for example, jamming). Simply replacing a part may not solve the problem for a long time.
Also, beginners often forget about thermal protection. Trying to start the refrigerator immediately after an unsuccessful attempt, they do not allow the posistor to cool down. It takes time for the posistor to restore resistance (usually 3-5 minutes), and restarting before this time will be unsuccessful.
Another mistake is using inappropriate tools. Do not forcefully pick at the plastic latches with a knife or screwdriver, as the plastic on old refrigerators becomes brittle and breaks easily. It is better to use plastic spatulas or work carefully with your fingers.
When to contact a professional
Despite the apparent simplicity, there are situations when self-repair is undesirable. If, after replacing the relay, the refrigerator still does not start or knocks out plugs, the problem may be deeper - in the compressor windings or an interturn short circuit.
If you are not confident in your skills in working with electricity, it is better not to take risks. Incorrect connection can lead to electric shock or failure of an expensive compressor, the replacement of which is not economically feasible.
Also, the help of a specialist is necessary if soldering of tubes or evacuation of the system is required. These operations require special equipment and skills that cannot be replaced with home tools.
Can a relay be repaired?
In some cases, electromagnetic relays can be disassembled and the contacts can be cleaned of carbon deposits, but this is a temporary measure. Modern posistor relays cannot be repaired and require mandatory replacement.
Understanding where the starting relay is located and how it functions gives you an advantage in diagnosing everyday problems. A competent approach to repairs extends the life of equipment and saves the family budget.
Is it possible to start a refrigerator without a starting relay?
Theoretically, you can start the engine by applying voltage directly to the starting winding, but doing this manually is extremely dangerous and ineffective. Without a relay, the compressor will not be able to switch to operating mode and will quickly burn out from overheating. Operation without a relay is impossible.
Why does the relay often burn out?
The main reasons are unstable voltage in the network, frequent power outages, as well as wear and tear on the compressor itself, which begins to consume more starting current. Overheating of the engine compartment due to poor ventilation at the back of the refrigerator also affects it.
How much does it cost to replace the start relay?
The cost of the part itself varies from 500 to 2000 rubles, depending on the model and brand. Replacing services usually cost from 1000 to 2500 rubles, not counting the cost of the spare part. Replacing it yourself allows you to save on work.
It buzzes, but does not start - is it really a relay?
In 80% of cases it is really a relay or a thermal release. However, if the compressor hums very loudly and strainedly, and then clicks, this may mean that the piston group is seized. In this case, replacing the relay will not help.