A sudden stop of the compressor and silence that reigns in the kitchen instead of the usual hum of a working unit often indicates a failure of the start-up relay. It is this small but critical element that is responsible for starting the engine and protecting the windings from overloads. Many owners of household appliances, faced with such a problem, begin to panic, believing that repairs will require expensive intervention from professionals.
However, if you have minimal skills in handling tools and follow safety precautions, replacing the PZR (start-up relay) can be done independently. In this article we will look in detail at how to correctly identify a malfunction, choose a suitable analogue and, most importantly, how to safely connect the PZR to your refrigerator. The process does not require deep knowledge of electrical engineering, but it does require attentiveness and accuracy.
Before starting work, you must clearly understand that any manipulations with electrical components are carried out only when the power is completely turned off. Unplug the refrigerator from the socket. This is not just a formality, but a vital rule, ignoring which can lead to electric shock or damage to the electronics of the unit.
Diagnostics of a malfunction of the start-up relay
The first step in the process of restoring the functionality of the refrigerator is the accurate identification of the problem. Start-up protection relay often fails due to power surges in the network or natural wear of the contact group. The main symptom of the malfunction is a characteristic click heard from the back of the refrigerator, followed by the hum of the compressor, but the engine itself does not start.
After a few seconds of this operation, another click is heard - this is the thermal protection, turning off the power. If you observe such cyclicity, then with a high degree of probability the problem lies in the relay. It is also worth paying attention to the condition of the compressor itself: if it overheats but does not start, this may indicate jammed contacts inside the PZR.
⚠️ Attention: If, after replacing the relay, the compressor continues to hum and does not start, the problem may lie in the motor itself or a break in the windings. Further attempts to start may permanently damage the unit.
For more accurate diagnostics, you can remove the relay and shake it near your ear. If a ringing or knocking sound is heard inside, it means that the contact group is damaged or torn off, and the part must be replaced. A visual inspection may also reveal traces of plastic melting or carbon deposits on the contacts, which is a direct indication of the need for repair.
Preparation of tools and selection of a new part
For a successful replacement, you will need a minimum set of tools. First of all, these are pliers or pliers that will help you carefully remove the terminals. You may also need a screwdriver (usually a Phillips or flat-head screwdriver) to remove the compressor protective cover if it is secured with screws. It would be a good idea to prepare a multimeter to check the continuity of the circuit, although in emergency cases you can do without it.
The most important step is choosing the right analogue. PZRs are selected strictly for the model of the compressor, not the refrigerator. There are always markings on the body of the old relay, for example RKT, RTK, R-1, R-3 or manufacturer codes like Danfoss, Secop. It is critically important to pay attention to the compressor power indicated on the nameplate (for example, 1/5, 1/4 hp) or to the marking of the relay itself.
There are no universal solutions, and installing a relay with inappropriate parameters can lead to rapid burning of the motor windings. If you cannot find the exact original, look for cross-analogs by checking the manufacturers' correspondence tables.
Correspondence table of popular relay models
RTK-X (Cold) → RKT (Gold-plated contacts)
R-1 → R-3 (Increased resource)
Danfoss 101L0021 → Compatible with most Atlant models
Removing the old start-up protection relay
The process of removing the faulty part begins with access to the compressor. It is usually located at the bottom rear of the refrigerator. Remove the cardboard or plastic cover covering the engine compartment. You will see a view of the black cylindrical compressor housing, to which a small plastic block is attached on one side - this is our desired relay.
Carefully remove the retaining bracket or bend the spring clips holding the relay to the compressor terminals. Do not make any sudden movements to avoid damaging the associated wires. If the wires are stiff, you can slightly heat them with a hairdryer (without overheating!) to make them more elastic.
Remove the relay from the compressor pins. Pay attention to the orientation: the top of the relay is usually marked with an arrow UP or text TOP. Remember or take a photo of which wire is connected where. Usually there are three of them: general, starting and working, but in modern models they can be assembled into one block.
☑️ Dismantling steps
Connection diagram and installation of a new PZR
Installation of a new element is carried out in the reverse order of dismantling. However, there is an important caveat: the contacts on the new relay and on the wires may not match perfectly in shape or size. In this case, you can carefully bend the contacts with pliers, ensuring a tight fit. Poor contact will lead to sparking and repeated failure of the part.
When connecting wires, be guided by the photos taken earlier or the markings on the terminals. The following designations are usually used:
- 🔌 L or Line —phase wire (common).
- 🚀 S or Start —starting winding (often goes through a capacitor).
- ⚙️ R or Run —working winding.
If your model uses capacitor, it is also connected to the corresponding relay terminals. Make sure that the capacitor is not swollen or has any signs of electrolyte leakage. After connecting all the wires, slide the relay onto the compressor pins. It should fit tightly, with a characteristic click or force.
| Relay type | Installation orientation | Compatibility | Feature |
|---|---|---|---|
| RTK (Gold-plated) | Strictly vertical (arrow up) | Atlant, Indesit | High reliability of contacts |
| P-1 / P-3 | Vertical | Biryusa, Minsk | Thermal protection in the housing |
| Danfoss / Secop | Depends on the model (often upwards) | Imported compressors | Often assembled with a capacitor |
| Universal | According to markings on the case | Various models | Requires adjustment of contacts |
Secure the relay with a metal bracket or spring. Make sure that the wires do not touch the hot compressor tubes and are not twisted. Now you can put the protective cover of the engine compartment back in place.
Checking functionality and first start
After installing all components, the moment of truth comes. Plug in the refrigerator. In the first seconds you will hear the hum of the compressor starting up. This is a normal situation. If after 3-5 seconds the hum turns into a smooth, confident hum, and the chamber begins to get cold - repair was completed successfully.
Pay attention to the behavior of the relay at the time of startup. It should make one clear click when turning on. If there is a lot of clicking, or the compressor hums but does not start, turn off the power immediately. This means that either the relay is selected incorrectly, or the problem is deeper (the compressor piston is jammed).
Let the refrigerator operate for about 30-40 minutes without loading food. Check the temperature of the evaporator (the back wall in the freezer) - it should be evenly covered with frost or become cold. Also touch the condenser (the grill at the back) - it should heat up.
Typical errors when replacing the relay
Even experienced craftsmen sometimes make mistakes that nullify all efforts. One of the most common is incorrect orientation of the relay in space. Most models (especially RTK and P-1) work only in a vertical position. If you turn the relay upside down, gravity will not allow the contacts to close or blur correctly.
Another common mistake is ignoring the condition of the wires. If the wires are burned or the insulation is cracked, they must be stripped and extended using heat shrink. An attempt to connect a new relay to the burnt wires will lead to heating of the contact point and a possible fire.
⚠️ Attention: Never leave the refrigerator running for a long time with the engine compartment open. This disrupts the air circulation to cool the compressor, which can lead to its overheating and tripping of the protection.
Also, you should not use the relay “at random”, just to fit the seats. The difference in cutoff current can be critical. If the relay operates too late, the motor windings will burn out. If it’s too early, the refrigerator simply won’t start.
Safety measures and prevention
Regular maintenance will help extend the life of your refrigerator. Once a year, it is recommended to remove the back cover and check the condition of the relay contacts and the cleanliness of the capacitor. Dust adhering to the radiator grille impairs heat transfer, causing the compressor to work with overload, which reduces the life of the starting relay start relay.
If voltage surges often occur in your home, be sure to use a stabilizer or at least a surge protector. Power surges are the main enemy of not only electronics, but also the starting equipment of refrigerators. A cheap stabilizer can save an expensive compressor from combustion.
When replacing parts, always use original components or proven analogues. Cheap Chinese relays without markings often have thin contacts that are welded to each other after several switching cycles, which again leads to the refrigerator stopping.
Is it possible to install a relay of a different brand if the original is not on sale?
Yes, it is possible, but only if the electrical characteristics (cut-off current, compressor power) and the geometric dimensions of the seats match. Often brand relays RTK can be replaced with universal analogues by selecting the desired contact group.
Why does a new relay burn out a week after installation?
There may be several reasons: poor contact in the terminals (sparking), incorrect the orientation of the relay, or, worst of all, a malfunction of the compressor itself (turn-to-turn short circuit), due to which it consumes too much current.
Is it necessary to discharge the freon before replacing the relay?
No, it is not necessary. Start-up