A sudden stop of the compressor or characteristic clicks when trying to start the refrigerator often indicate a failure of one of the key elements of the electrical circuit. Start-up protection relay is responsible for starting the engine and protecting the windings from overloads, so its location and serviceability are critical for the operation of the entire cooling system. Many owners of household appliances do not know that this small component is hidden from view and requires access to the rear of the unit for visual inspection.
Finding the location of starting relaydoes not require deep engineering knowledge, but does require compliance with strict safety rules when working with electrical appliances. In most modern and old models, be it Indesit, Atlant or LG, this unit is located in close proximity to the compressor. Understanding the design of this unit will allow you to independently carry out initial diagnostics and decide whether to call a technician or replace the part yourself.
In this article we will analyze in detail the anatomy of the compressor compartment, describe the algorithm for searching and dismantling the device, and also provide signs by which you can determine the breakdown of this particular element. It is important to understand that even if you plan to entrust the repair to professionals, knowing the location of the main components will help you more accurately describe the problem and avoid unnecessary diagnostic costs.
Anatomy of the compressor compartment and relay location
To find start-up protection relayyou need to gain access to the lower rear part of the refrigerator. It is there, in the so-called compressor compartment, that the “heart” of the refrigerator is located - the motor-compressor. The relay is always mounted directly on the side or top of the compressor housing, covering the contact group. It is a small plastic box of black or white color, to which a bundle of electrical wires fits.
The design of the fastening may vary slightly depending on the manufacturer and year of manufacture of the model. In some cases, the relay is simply put on three pins coming out of the compressor housing, in others it is fixed with a metal bracket or snapped into a special groove. Thermal relay, which is often combined with the starting one into a single unit, is also located inside this casing or adjacent to it, reacting to the current strength in the circuit.
⚠️ Attention: Before starting any work to find and dismantle the relay, be sure to disconnect the refrigerator from the power supply! Working with live electrical wiring is deadly, and the compressor may be under residual charge.
Access to the compartment is usually unrestricted, however, in some models with the system No Frost or built-in refrigerators, access may be difficult due to structural elements or decorative panels. If you see a black metal tank (this is the compressor), then the part you are looking for is located on its protruding shank, where copper tubes and electrical contacts come out.
Visual signs and types of relays
Before removing a part, it is useful to understand what it looks like so as not to damage adjacent elements. Start relay c Older models of refrigerators (for example, Soviet or early European) often have a massive body made of carbolite or heat-resistant plastic and can be gold-plated or copper in color. Inside such devices there is a coil and a movable core that operates on the electromagnetic principle.
Modern models are often equipped with positor relays. They are more compact, lighter and do not have moving mechanical parts in the traditional sense. Inside the plastic case there is a ceramic element - a posistor, which changes its resistance when heated. Visually, such relays look like small black boxes with markings, often with the manufacturer’s logo, such as Danfoss, Secop or Embraco.
On the body of the part there is always a marking containing technical information: supply voltage, type of refrigerant for which the compressor is intended, and orientation installation. The "UP" or "UP" arrow on the relay body indicates the correct position during installation - this is critical for the correct operation of the mechanism. If the part is installed incorrectly, the contacts may not close and starting the engine will not be possible.
During external inspection, pay attention to the condition of the plastic. If you see melting, blackening, cracks, or smell a burning smell coming from the relay, this is a sure sign that it is failing. It is also worth checking the integrity of the wires going to the connector: they should not be frayed or have traces of oxidation of the contacts.
Step-by-step instructions for dismantling the device
The process of removing the start-up relay is quite simple, but requires care. After unplugging the refrigerator and moving it away from the wall to provide easy access to the back wall, you can begin dismantling. You may need a flathead screwdriver and possibly some pliers, although this is often done by hand.
You will first need to remove the compressor guard, if equipped. In some models it is a metal plate secured with bolts, in others it is a plastic cap secured with latches. Under it you will see the compressor itself and the relay attached to it. Next, proceed according to the following algorithm:
- 🔌 Disconnect the electrical connector that supplies power to the relay and compressor. It may fit tightly, so rock it slightly from side to side, but do not yank the wires.
- 🔧 Remove the retaining bracket or bar if the relay is pressed against the motor housing. The bracket is usually removed by moving upward or to the side after unscrewing the screw.
- 🤏 Carefully remove the relay itself from the contact pins of the compressor. It can stick or stick over time, so a slight rocking will help to remove it.
- 👀 Inspect the seat on the compressor: there should be no carbon deposits, moisture or foreign objects.
If the relay is difficult to remove, do not use excessive force so as not to break the plastic ears or damage the ceramic insulators on the compressor itself. In such cases, you can slightly warm the relay body with a hair dryer (at minimum temperature) to soften the plastic, but this must be done extremely carefully.
☑️ Checklist before removing the relay
Diagnostics of faults in the starting element
Understanding how it works starting relay, helps in diagnostics. Its task is to supply increased starting current to the starting winding of the engine at the moment of start, and then turn off this winding when the motor reaches the required speed. In parallel with this, thermal protection monitors temperature and current, opening the circuit when overheated.
The most common breakdown is sticking contacts or destruction of the internal mechanism. If the contacts are stuck in the closed state, the starting winding remains on constantly, which leads to the humming of the compressor and its rapid overheating. In this case, the thermal relay should operate and break the circuit, after which you will hear a click, and after a while the start attempt will be repeated.
If the contacts, on the contrary, do not close (the posistor is destroyed or the contacts are burnt), the compressor will hum quietly or simply click, but will not start. In this case, the motor shaft does not receive the required torque. You can check the integrity with a multimeter in continuity mode:
⚠️ Attention: Diagnostics with a multimeter is only possible with the relay completely de-energized and disconnected from the compressor. An attempt to make a call on a connected device will cause the tester to burn out.
The table below shows the main symptoms and their probable causes associated with the relay:
| Symptom | Probable cause in the relay | Action |
|---|---|---|
| Clicks and silence | Open circuit of the posistor or contacts | Replacing the relay |
| Humming and heating | Sticking of contacts (starter does not turn off) | Replacing the relay and checking the compressor |
| Tripping of protection | Malfunction of the thermal element | Replacing the relay |
| Random stops | Unstable contact or overheating | Cleaning contacts or replacing |
It is important to note that relay failure is often secondary. If the compressor has a mechanical defect (jamming) or an interturn short circuit, it consumes too much current, which leads to rapid failure of even a new one. Therefore, before installing a new part, it is advisable to make sure that the motor itself is in good working order. start relay. Therefore, before installing a new part, it is advisable to make sure that the motor itself is in good working order.
Is it possible to temporarily start a refrigerator without a relay?
Theoretically, you can close the contacts manually for a split second to start, but this is extremely dangerous and is not recommended. The compressor will remain running on one working winding, which will lead to its overheating and eventual combustion after a short time. This is a method only for diagnostics, but not for operation.
Replacement and selection of a new relay
Start-protective relays are practically not repairable. Attempts to disassemble the case, clean contacts, or glue cracks together give only a short-term effect and do not guarantee the safety of further operation. The cost of a new part is usually low, so the only correct solution is to completely replace the unit.
When choosing a replacement, focus not only on appearance, but also on technical parameters. The key ones are the motor power (in watts or horsepower), the type of refrigerant (R134a, R600a) and the type of compressor. Universal relays exist, but they do not fit all models. It is best to look for an original spare part using the code indicated on the body of the old device.
The process of installing a new element occurs in the reverse order of dismantling. Make sure that the arrow on the housing is pointing upward (or in the direction indicated in the instructions), and firmly seat the relay on the pins until a characteristic click or stop occurs. Securely fasten the fixing bracket and connect the electrical connector.
After assembly, do not rush to put away the tools. Plug in the refrigerator and listen. Start-up should be smooth, without strong impacts or prolonged buzzing. After a few minutes, the compressor should begin to heat up evenly, and cold should appear in the refrigeration chamber.
Prevention and service life of the part
The average service life of a high-quality start-up relay is 10-15 years, however, unstable voltage in the network, frequent temperature changes and poor ventilation of the compressor compartment can shorten this period. To extend the life of the part, it is recommended to ensure free access of air to the rear wall of the refrigerator.
Regular dust removal in the compressor area also plays an important role. The dust “carpet” acts as a heat insulator, preventing the compressor and relay from cooling, which leads to more frequent thermal protection trips and degradation of materials. Wipe the back panel with a damp cloth every six months.
If you live in an area with unstable power supply, using a voltage stabilizer or at least a surge protector with surge protection will help protect not only the relay, but also the entire electronics of the refrigerator. Voltage surges are one of the main causes of insulation breakdown and failure of starting elements.
⚠️ Attention: Technical characteristics and location of components may vary depending on the specific model and year of manufacture of the refrigerator. Always check the manufacturer's official technical documentation to obtain accurate data on your device.
Timely replacement of a faulty relay is not only a restoration of cold, but also the salvation of an expensive compressor. Ignoring the symptoms of a malfunction (frequent clicks, humming) can lead to the need to replace the entire unit, since the cost of a new motor and the work to replace it is often comparable to the price of a new refrigerator.
Why can a relay burn out immediately after replacement?
A common reason is a jammed compressor. If the engine cannot crank mechanically, the current in the windings increases to a maximum, and the thermal protection of the new relay is activated instantly, or it burns out. In this case, diagnostics of the compressor is needed.
Frequently asked questions (FAQ)
Is it possible to test the relay without a multimeter?
It is difficult to accurately determine the functionality of internal contacts without instruments. However, if you shake the relay near your ear, there should be no rattling sound inside (other than slight movement of the core in some types). Also, a visual inspection for burning and melting provides 80% of the information about the condition of the part.
Why is the compressor hot, but the refrigerator does not freeze?
This may indicate that starting relay does not turn off the starting winding, and the motor is operating in emergency mode, or that the compressor has lost performance (compression) due to wear of the valves, although it starts.
Where to buy an original relay for an old refrigerator?
Original spare parts for old models (for example, Biryusa or ZIL) can often be found in specialized stores of spare parts for household appliances or at radio markets. For modern models, it is enough to know the part code and order it in online stores.
Is it safe to use a universal relay?
The use of universal relays is permissible if their current characteristics overlap the parameters of your compressor. However, they may work less stably or have a different operating algorithm, so the original spare part is always preferable.