A sudden stop of the compressor or a characteristic click followed by silence are often the first signals that starting relay has failed. This small but critical component is responsible for starting the motor by ensuring that the required voltage is supplied to the windings when it is turned on. If you ignore the symptoms of a malfunction, you may encounter overheating of the motor or complete failure of the refrigeration chamber.
Independent replacement of the element is possible if you have basic tools and follow safety precautions. It is important to understand that electromagnetic and thermal relays have different designs, so the approach to diagnosing them may differ. In this article, we will analyze in detail the process of dismantling the old device and installing a new one so that your refrigerator works flawlessly again.
Before you start disassembling, you need to make sure that the problem lies in the relay, and not in the wiring or the compressor itself. The main sign of a relay malfunction is that the compressor hums for 1-3 seconds, clicks and turns off without starting. If you observe exactly this picture, then the probability of failure of the starting mechanism is extremely high.
Symptoms of malfunction and preliminary diagnostics
You can determine if a relay is broken not only by sound signals, but also by the appearance of the device after it is removed. Often inside the case you can see traces of burning, melted plastic or blackened contacts. Thermal relay It may simply stop opening the circuit, which will lead to constant operation of the fan or, conversely, to a lack of response to switching on.
For accurate diagnostics, experts recommend using a multimeter in dial mode. The resistance of a working device should be close to zero, and when heated (for thermal models), the circuit should break. If the tester shows an open or infinite resistance when cold, the part requires replacement.
Pay attention to the following symptoms that indicate the need for intervention:
- ⚡ The compressor makes a loud beep, but does not start, followed by a clicking sound.
- 🔥 The relay housing has visual signs of overheating, melting or deformation.
- 🔇 The refrigerator is completely silent, although the power indicators are on and the network is working.
- 🔄 The engine starts only after several attempts to turn on or tap on the case.
⚠️ Attention: If after replacing the relay the compressor continues to hum and does not start, the motor itself may be jammed or an interturn short circuit of the windings has occurred. Further attempts to start may lead to burning of the wiring.
Necessary tools and safety measures
Working with electrical appliances requires strict adherence to electrical safety rules. Before starting any manipulations, you must completely turn off the power to the refrigerator by removing the plug from the socket. Even briefly touching live parts can cause serious injury, so do not neglect this rule.
To successfully complete the task, you will need a minimum set of tools, which can be found in the garage of most home craftsmen. Pay special attention to the quality of insulation of tool handles, since the risk of residual charge in capacitors (albeit minimal in older models) or accidental contact with the network cannot be completely excluded.
List of necessary equipment for repairs:
- 🔧 Screwdrivers (flat and Phillips) for removing the back panel and clamps.
- 🔌 Multimeter or tester for checking circuit continuity and resistance.
- 🧤 Dielectric gloves to protect hands when working with electricity.
- 🧹 Sandpaper or alcohol to clean contacts from oxides and dirt.
Removing the old start relay
The process of removing the device begins with access to the compressor, which is usually located in the lower rear part of the unit. Carefully move the refrigerator away from the wall, giving yourself enough room to maneuver, and remove the metal or plastic protective panel covering the engine compartment. The fastenings can be made with screws or snaps, so be careful not to damage the plastic.
On the compressor pipe you will see a box placed directly on the motor terminals. It can be fixed with a metal clamp or simply fit tightly due to the design of the case. If a clamp is used, it must be loosened with pliers. In some models Indesit or Atlant the relay is additionally secured with a screw to the frame of the refrigerator.
After removing the fixing element, gently rock the relay from side to side and pull it down. Do not apply excessive force to the wires - if the device cannot be removed, the contacts may be stuck or the insulation is interfering. After dismantling, inspect the wires for insulation melting, which often happens when a faulty relay operates for a long time.
☑️ Checklist before removing the relay
Installing a new relay and connecting the contacts
Installation of a new device requires attention to the orientation of the contacts. Most relays have a marking or diagram on the body indicating which terminal corresponds to the starting winding and which to the operating winding. Incorrect connection can lead to immediate failure of the new part or damage to the compressor.
First, place the wire terminals on the corresponding pins of the new relay. Make sure the connection is tight and not loose; if the contacts are oxidized, clean them until they are shiny. Then carefully put the assembled structure on the three pins coming out of the compressor, maintaining a vertical position (the arrow on the body should look up).
Pin correspondence table for different types of relays:
| Relay type | Pin marking | Wire color (standard) | Installation features |
|---|---|---|---|
| Electromagnetic | M, S, R | Black, Red, White | Strict verticality |
| Thermal (RTK) | No marking | Depends on the model | Orientation along the arrow is important |
| Posistor | 1, 2, 3 | Varies between brands | Less sensitive to position |
| Two-contact | L, N | Phase and Zero | Used in older models |
After installing the relay in place, return the fixing bracket or screw. Make sure that the device sits tightly and does not loosen when the compressor vibrates. Only after secure fixation can you proceed to a test run of the system.
⚠️ Attention: It is strictly forbidden to turn on the refrigerator if the relay is installed upside down or sideways, if the design does not provide for such installation. The internal mechanism (contacts or posistor) will not work correctly.
Checking functionality after replacement
The first start after repair is a critical moment. Plug in the refrigerator and listen carefully. After a few seconds, you should hear the confident hum of a running compressor, which will last for several minutes. If you hear only a single click and silence, immediately unplug the device.
In normal operation, the relay should operate at the moment of startup, and then (depending on the type) either remain in the circuit or break the starting circuit. Check the heating of the relay body after 10-15 minutes of operation - it should not be excessive. Only light heat is allowed.
Main stages of testing:
- 👂 Listen to the startup sound: it should be smooth, without rattling or repeated clicks.
- ❄️ Control the cold: after 30-40 minutes in the chamber it should start get cold.
- 🌡️ Check the temperature of the relay body: it should not burn your fingers.
- 🔌 Inspect the contacts: after 10 minutes of operation there should be no sparking inside (if visible).
Typical mistakes during self-repair
One of the most common mistakes is ignoring contact cleaning. Even a new relay will not work well if there is an oxidized film or carbon deposits left on the compressor response pins. Always take the time to prepare the contact surfaces using fine sandpaper or alcohol.
Another common problem is using a relay from another refrigerator model by eye. Externally, the devices may be identical, but their current characteristics (amperage) may differ. Installing a relay with a lower current will lead to its permanent shutdown, and with a larger one, it will burn out the motor windings.
Critical mistakes that should be avoided:
- 🚫 Attempting to repair a burnt-out relay by cleaning the contacts (the effect is temporary and dangerous).
- 🚫 Installing a part without fixation with a bracket, which leads to vibration and destruction of contacts.
- 🚫 Ignoring checking the voltage in the network (low voltage will not allow the relay to operate).
- 🚫 Using electrical tape instead of the original terminals to connect wires.
Questions and answers about replacement relay
Is it possible to temporarily start a refrigerator without a relay?
Technically, you can start the engine by closing the contacts manually, but doing this is strictly prohibited in domestic conditions. This requires precise knowledge of the moment the circuit opens, otherwise the compressor will burn out in a few seconds due to the operation of only the starting winding.
Why did the new relay burn out after a week?
There may be several reasons: the amperage was incorrectly selected, poor contact in the connector causing sparking, or, worst of all, the compressor itself is faulty (turn-to-turn short circuit), which consumes increased current.
What is the difference between the RTK relay and R-3?
The RTK relay (thermal) works on the principle of heating a bimetallic plate and often makes clicks during operation of the refrigerator. R-3 (electromagnetic) is triggered by current in the starting winding and is usually installed in more modern or powerful models. They are not always interchangeable without changing the circuit.
Do you need to wait until the compressor cools down before replacing?
It is advisable to let the compressor cool, especially if it has just tried to start. The thermal relay may be hot, and the motor itself may be heated, which will complicate diagnostics and may be unsafe for your hands.
Where can I find the markings of a suitable relay?
The markings are usually applied to the side or top edge of the old relay. Look for numbers like 1/4, 1/5, 1/6 (horsepower) or a direct indication of amperes (Amps). You can also search by refrigerator model in spare parts catalogs.