Connecting a relay in a refrigerator: diagrams, tools and step-by-step instructions

A relay in a refrigerator is a small but critical component that is responsible for starting the compressor and protecting it from overloads. Without a properly connected relay, the motor will either not start or will quickly fail due to overheating. However, many owners are faced with the need to replace or connect the relay themselves - be it due to a breakdown, upgrading the system or purchasing used equipment without original parts.

In this article we will analyze types of relaysused in refrigerators (starting, protective, combined), show circuits connections for popular models (Atlant, Indesit, Stinol), we will list the necessary tools and give step-by-step instructions with photographs of key stages. We will pay special attention common errors, which lead to a short circuit or failure of the compressor. If you have never worked with electricity, it is better to entrust the task to a specialist, but if you have basic skills and follow safety precautions, you can connect the relay yourself.

Types of relays in refrigerators: which one is suitable for your model?

Before Before buying a new relay, you need to determine what type is installed in your refrigerator. Not only the connection diagram, but also the principles of fault diagnosis depend on this. All relays are divided into three main categories:

• 🔧 Start relay —responsible for short-term connection of the compressor starting winding at the time of startup. Without it, the motor will not be able to overcome inertia and start rotating.
• 🛡️ Protective relay - opens the circuit when the compressor windings overheat or voltage surges. Often integrated into the starting one (combined models).
• ⚡ Combined relay (start-protective) - combines both functions. The most common option in modern refrigerators LG, Samsung, Beko.

How to understand which relay is in your refrigerator? First, look at the markings on the old relay (if it is still there). For example, the inscriptions DANFOSS 103N0210 or RBM-1 indicate combined models. Secondly, estimate the number of contacts:

• 2-3 contacts - most likely only protective.
• 3-4 contacts - starting or combined.

Thirdly, check the documentation for the refrigerator: in sections about electrical circuits, the type of relay is usually indicated.

⚠️ Attention: Relays from refrigerators Stinol and Atlant older than 2010 are often incompatible with modern compressors due to different current characteristics. Before purchasing, check the parameters with the table below.

Tools and materials: what you will need for connection

To replace or connect the relay, you do not need professional tools - a basic set, which can be found in most homes, is enough. However, there are several nuances that you should know about in advance:

• 🔌 Phillips and flat head screwdriver — for dismantling the compressor cover and attaching the relay. Some models (Samsung) use screws with a non-standard head (Torx T10), so check them in advance.
• 📏 Multimeter - to check the resistance of the compressor windings and the integrity of the relay contacts. Without it, you will not be able to diagnose the malfunction.
• ✂️ Side cutters and pliers - for crimping terminals (if the wires are damaged) and carefully removing the insulation.
• 🔗 Heat shrink tube or electrical tape - for insulating connections. In refrigerators with inverter compressors (LG, Hitachi), it is recommended to use heat shrink - it protects more reliably from moisture.
• 🔍 Flashlight or table lamp - the lighting of the compressor compartment is usually weak, and you will have to work with small details.

Also prepare:

• New relay (suitable model - see table above).
• Alcohol or contact cleaner - to remove oxidation from the terminals.
• Dielectric gloves (if you are not sure that there is no voltage in the network).

⚠️ Attention: In refrigerators with a system No Frost (for example, Beko, Electrolux) the relay is often hidden under the control panel. To access it, you may need to remove the top cover of the case - study the disassembly diagram for your model in advance.

Disconnect the refrigerator from the network (unplug the plug from the socket)|

Take a photo of the current relay connection (for reference)|

Check the compressor with a multimeter (winding resistance)|

Prepare the workplace (good lighting, no moisture)-->

Relay connection diagrams: analysis of popular options

The relay connection diagram depends on the type of compressor and model of the refrigerator. Below we have given the three most common options. Important: before starting work, compare your diagram with the one printed on the relay body or in the documentation for the refrigerator.

1. Standard circuit for compressors with three terminals

Used in most refrigerators Atlant, Biryusa, Nord. The compressor has three contacts:

• C (Common) - general output;
• S (Start) - starting winding;
• R (Run) - working winding.

The relay is connected as follows:

• Terminal C compressor → terminal 3 relay.
• Terminal S → terminal 2 relay.
• Terminal R → terminal 1 relay.
• 220V power is supplied to the terminals 1 and 3 relay.

2. Scheme for compressors with separate starting and protective relays

Found in older models Stinol, ZIL and some Indesit. Here the starting relay is connected to the compressor windings, and the protective relay is connected in series to the phase wire break. Connection order:

• Phase wire (220V) → protective relay → starting relay (terminal L).
• Zero wire → directly to the working winding (R).
• Starting winding (S) is connected via a normally open contact of the starting relay.

3. Circuit for inverter compressors

Refrigerators LG, Samsung with inverter motors use electronic relays that are controlled by a board. Here, independent connection strongly not recommended - an error can lead to failure of the entire control unit. If the inverter relay fails, it must be replaced only with an original part with the same marking.

For clarity, here is a universal connection diagram for a standard combined relay:

220V ~
│
├───[Protective relay]───┬───[Start relay]─── S (Start)
│                      │
│                      └─── R (Run)
│
└────────────────────── C (Common)

How to check the correct connection?

After connecting the relay (but before starting the refrigerator) check the circuit with a multimeter:

1. Set the resistance test mode (200 Ohm).

2. Between terminals 1 and 3 of the relay, the resistance should be ~20–40 Ohms (working winding).

3. Between terminals 1 and 2 - ~10–20 Ohms (start winding).

4. Between 2 and 3 is the sum of the resistances of the starting and operating windings (~30–60 Ohms).

If the values ​​are very different, check the quality of the contacts or the integrity of the compressor windings.

Step-by-step instructions: how to connect a relay in a refrigerator

Now let's move on to practice. Follow the instructions strictly step by step, without skipping verification steps. For example, let's take the replacement of a combined relay in a refrigerator Atlant.

Step 1: Disconnection and disassembly

• Unplug the refrigerator from the socket. If the power cord is hidden behind the rear panel, turn off the circuit breaker in the panel.
• Move the refrigerator away from the wall to gain access to the compressor (usually located at the bottom of the rear wall).
• Remove the protective cover of the compressor by unscrewing 3-4 screws with a Phillips screwdriver.
• Take a photo of the current connection of the relay (this will help avoid mistakes during reassembly).

Step 2: Dismantling the old relay

• Carefully remove the terminals from the relay contacts, remembering their location. If the wires are secured with screws, loosen them with a screwdriver.
• Unscrew the relay from the compressor housing (usually it is secured with 1-2 screws).
• Check the condition of the contacts: if they are oxidized, clean them with alcohol or fine sandpaper.

Step 3: Connecting a new relay

• Install the new relay in place of the old one and secure it with screws.
• Connect the terminals according to the diagram (see section above). In refrigerators Atlant the order is usually used: 1 → R, 2 → S, 3 → C.
• Tighten the terminal screws with pliers (do not overdo it so as not to strip the threads).

Step 4: Checking and starting

• Make sure that all wires are securely fastened and do not touch the compressor housing.
• Plug in the refrigerator. The compressor should start in 1-2 minutes (delay time depends on the model).
• Listen to the sound of operation: if the motor hums, but does not start, the relay may be faulty or incorrectly connected.

⚠️ Attention: If after connecting the relay the compressor starts, but after 5-10 seconds it turns off, this is a sign of a malfunction. protective part of the relay or interturn short circuit in the windings. Do not ignore this symptom - prolonged operation in this mode will lead to motor breakdown.

Common mistakes and how to avoid them

Even experienced craftsmen sometimes make mistakes when connecting a relay. We have collected the most common of them and explained what they lead to:

• ❌ The terminals are mixed up S and R — the compressor does not start or works in the opposite direction (which leads to overheating). Always check the diagram!
• ❌ Weak terminal contact —leads to heating and melting of the plastic relay housing. Tighten the screws with pliers, not a screwdriver.
• ❌ Using a relay from another model —even if it looks similar, the current characteristics may not match. For example, a relay from Indesit is not suitable for Atlant due to the different starting current.
• ❌ Ignoring the compressor test —if the windings are closed, the new relay will burn out immediately after startup. Always check the resistance with a multimeter!
• ❌ Operation under voltage is not only life-threatening, but can also damage the electronic components of the refrigerator (for example, the control board in Samsung).

Pay special attention insulation of connections. In refrigerators with an auto-defrost system (No Frost), condensation can get on the contacts, causing corrosion. Use heat-shrink tube instead of electrical tape - it is more airtight.

Diagnostics of relay faults: when replacement is needed

How to understand that the relay has failed and needs to be replaced? Here are the key signs:

• 🔊 The compressor does not start, but a slight hum is heard. (the relay does not close the starting winding).
• ⚡ The compressor turns on and immediately turns off —the protection is triggered due to overheating.
• 🔥 The relay gets hot or smells like burning —a sign of an internal short circuit case.
• 🛠️ Visible damage: cracks on the case, melted contacts, traces of oxidation.

For an accurate diagnosis, follow these steps:

1. Disconnect the refrigerator from the network.
2. Remove the relay and inspect it for damage.
3. Test the relay contacts with a multimeter:
   • In normal condition between the terminals 1 i 2 resistance should be ~10–20 Ohm.
   • Between 1 and 3 — ~20–40 Ohm.
   • If the resistance is 0 (short circuit) or infinity (break) - the relay is faulty.

Check the compressor: the resistance between the terminals C–S and C–R should be within 10–50 Ohms. If at least one winding is broken, the relay has nothing to do with it, the motor needs to be repaired.

⚠️ Attention: In refrigerators with electronic control (LG, Liebert), a relay malfunction may appear as an error on the display (for example, a code Er FF or Er dHIn this case, diagnostics of the control board is required, and not just replacing the relay.

Features of connecting relays in refrigerators of different brands

The design of the relay and connection diagrams may differ significantly depending on the manufacturer. Let's consider the key features for popular brands.

Atlant and Biryusa

Most models use a combined relay RTK-X or DANFOSSFeatures:

• The relay is attached directly to the body compressor.
• The terminals are marked with numbers (1, 2, 3), which simplifies the connection.
• A common problem is oxidation of the contacts due to high humidity. When replacing, clean the terminals with alcohol.

Indesit i Ariston

Separate starting (RBM-1) and protective (LRI-15) relays are used. Important:

• The protective relay is often used. located on the wire, not on the compressor.
• The starting relay can be in a plastic or metal case - they are not interchangeable!
• In models with No Frost the relay is hidden under the control panel - partial disassembly is required.

Stinol i ZIL (old models)

Old model relays are often found here (RTP-1, TRN-2). data-i="294">RTP-1

• The relay housing can be dismountable - inside there is a bimetallic plate that can be replaced separately.
• The connection diagram often differs from modern standards (see the section on circuits).
• Carefully check compatibility with the compressor - old relays are not designed for high starting currents of new motors.

LG i Samsung (inverter models)

These refrigerators use electronic relays that:

• They are controlled by a board, so independent replacement is only possible with an original part.
• Often integrated into the control unit - if a breakdown occurs, the entire module must be replaced.
• Sensitive to power surges - in case of frequent power outages, it is recommended to use a stabilizer.

If your refrigerator is not listed, check the markings on the compressor. For example, the inscription Embraco EG means that a relay DANFOSS 103N or its analogues is suitable.

FAQ: Frequently asked questions about connecting a relay in a refrigerator

Is it possible to connect a relay from another refrigerator if it looks similar?

No, even if the relay is identical in appearance, its current characteristics (starting current, delay time) may not be suitable for your compressor. For example, a relay from Indesit with a starting current of 5 A will not be able to start a compressor Atlantthat requires 8-10 A. Always check the compatibility table or documentation.

After replacing the relay, the compressor hums, but does not start. What is the problem?

There may be several reasons:

• Incorrect connection of the terminals (check the diagram).
• Compressor malfunction (jammed rotor or broken winding).
• Voltage in the network is too low (less than 190V).
• Defect of the new relay (rare, but possible).

Disconnect the refrigerator and check the resistance of the compressor windings with a multimeter. If the values ​​are normal, double-check the connection diagram.

Do you need to solder the wires when connecting the relay?

No, refrigerators use screw or spring terminals that do not require soldering. Soldered connections, on the contrary, are not recommended - they can melt when the contacts heat up. It is enough to tighten the screws tightly and insulate the exposed sections of the wire.

How to check whether the relay is working without removing it from the refrigerator?

You can perform a quick diagnosis:

1. Disconnect the refrigerator from the network.
2. Remove compressor cover and find the relay.
3. Shake the relay - if you hear knocking or rattling inside, this is a sign of mechanical wear (replacement is required).
4. Turn on the refrigerator and listen: if the relay clicks, but the compressor does not start, the problem is in the motor windings or in the relay.

For an accurate check, you still have to remove the relay and ring with a multimeter.

How much does it cost to replace a relay in a service center?

The cost depends on the model of the refrigerator and the type of relay:

• Replacing a standard relay (Atlant, Indesit) - 1500–2500 rubles (including parts).
• Replacement of electronic relay (LG, Samsung) - 3000–5000 rubles (board diagnostics are often required).
• Repair of old-style relays (Stinol) - 1000–1500 rubles (if it is possible to replace the bimetallic plate).

Independent replacement will cost 300–1000 rubles (the cost of the relay itself).