When the refrigerator stops freezing, but the light inside is on and the motor does not start, the problem often lies in the start relay compressor. This small block is responsible for starting the engine and protecting against overloads. You can connect the wires to the relay yourself even without experience - the main thing is to understand the circuit and follow safety precautions.
In this article you will find step-by-step instructions with photographstypical mistakes of beginners, as well as universal connection diagrams for popular models of refrigerators (Atlant, Indesit, Stinol, LG). We will look at how to distinguish a starting relay from a protective relay, what to do if the wires are oxidized, and how to check functionality after connection.
Design and types of refrigerator relays
A starting relay is an electromechanical or electronic device that performs two functions: starts the compressor and protects it from overheating. Depending on the model of the refrigerator, the relay can be:
- 🔧 Induction (the most common type, used in older models Atlant, Biryusa)
- 💡 Electronic (posistor) (modern refrigerators Samsung, LG, Bosch)
- 🔄 Combined (combines starting and protective modules, for example, in Indesit or Stinol)
Inductive relays have a characteristic case with a coil and core, and electronic relays have a compact board with resistors. recognize by a small black or brown cylinder (posistor), which heats up and opens the circuit when overloaded.
It is important to understand that starting relay is responsible for starting the motor, and protective for turning it off in case of overheating. In some models (for example, Whirlpool) these functions are divided into two separate blocks.
Tools and materials for work
Before Before you start connecting, prepare everything you need. Without the right tools, you risk damaging the terminals or mixing up the wires.
- ⚡ Multimeter (to check the resistance of the windings and circuit integrity)
- 🔧 Screwdrivers (cross and flat, for removing the relay cover)
- 🔪 A knife for stripping wires (or a special stripper)
- 🧲 Soldering iron with solder (if the wires are oxidized and need to be restored)
- 📏 Heat shrink tube or electrical tape (to insulate connections)
- 🔍 Magnifying glass or flashlight (to see the markings on the terminals)
If the relay is burnt out, you should also you will need new relay, suitable for the compressor model. You can find out its type by the marking on the body of the old relay or by the compressor number (for example, Danfoss NL12FX or Secop SC10E).
⚠️ Attention: Do not use side cutters or wire cutters to strip wires - they may break the wires. The best option: a knife with a sharp blade at an angle of 30°.
Wiring diagram for the relay
The standard wiring diagram is the same for most refrigerators, but may differ depending on the type of relay. Below is the universal wiring. for induction and posistor relays:
| Relay terminal | Purpose | Wire color (typical) | Where to connect |
|---|---|---|---|
S (Start) |
Starting winding | Brown or black | To the starting winding of the compressor (S) |
R (Run) |
Working winding | Red or orange | To the working winding of the compressor (R or M) |
C (Common) |
General contact | Yellow or white | To 220V network (via thermostat) |
L (Line) |
Input power supply | Blue or black | To the refrigerator plug (phase) |
In electronic relays, the terminals may be marked differently (for example, 1, 2, 3In this case, refer to the diagram, which is usually printed on the relay body or in the instructions). refrigerator.
How to check the markings if they are erased?
If the inscriptions on the relay are not readable, use a tester: ring the contacts in resistance mode. Between S and C the resistance should be ~20-40 Ohms. (starting winding), between R and C — ~10-20 Ohm (working winding).
For refrigerators Atlant and Stinol a relay is often used RTK-X or DHR, where the terminals are located vertically. Models Samsung and LG usually have electronic relays with horizontal contacts.
Step-by-step instructions for connecting
Before starting work unplug the refrigerator and wait until the capacitor is discharged (5-10 minutes) Next, follow the algorithm:
Disconnect the refrigerator from the outlet
Remove the back cover (if the relay is hidden)
Take a photo of the current wire connection
Ring the compressor windings multimeter-->
Remove the relay from the compressor. It is attached with latches or screws. Gently pull the block up without pulling the wire.
Strip the wires. If the contacts are oxidized, remove the deposit with sandpaper or a knife. the bare part should be no more than 5 mm.
Connect the wires according to the diagram:
- Wire from the thermostat → terminal
C(Common). - Start winding (
S) → corresponding terminal on the relay. - Working winding (
R) → terminalRorM. - Phase wire from the plug → terminal
L.
- Wire from the thermostat → terminal
Attach the relay to the compressor. Make sure that it fits tightly - vibration can break the contact.
Check the connection. Turn on the refrigerator for 1-2 minutes. If the compressor starts and does not heat up, everything is done correctly.
⚠️ Attention: If after connecting the relay clicks, but the compressor does not start, check starting capacitor (if it is in the circuit) its capacity should correspond to the compressor model (usually 15-45 uF).
Critical error: connecting the starting winding (S) instead of the working one (R) leads to overheating of the compressor in 10-15 minutes. If you do not notice this in time, the motor will burn out.
Typical mistakes and how to avoid them
Even experienced craftsmen sometimes make mistakes when connecting a relay. Here are the most common of them:
- 🔌 Mixed wires
SiR. Symptoms: the compressor hums, but does not start, or overheats. Solution: swap the wires. - 🔥 Poor contact at the terminals. Symptoms: the relay clicks, but no current flows. Solution: strip the wires and tighten the terminals with pliers.
- ⚡ Ignoring winding checks. If one of the compressor windings is broken, the relay will not be able to start the motor. Always ring the compressor before connecting!
- 🛠️ Use of an incompatible relay. For example, a relay from Atlanta is not suitable for Samsung with an inverter compressor. Solution: select a relay according to the compressor model.
Another common problem is oxidation of contacts inside the relay. If, after connecting, the refrigerator is unstable (it turns on and off), disassemble the relay and clean the contact group with alcohol or a special liquid.
How to check the functionality after connecting
After connecting the relay, you need to make sure that the compressor is working correctly:
Plug in the refrigerator. After 1-2 seconds it should sound one-time clicking - this is the start relay.
Listen to the compressor: it should hum evenly, without outsiders knocks or vibrations.
Check the temperature of the compressor housing after 10 minutes of operation. It should be warm, but not hot (maximum 60-70°C).
Use a multimeter in current measurement mode (if you have access to the contacts). Normal starting current is 1.5-3 A, operating current is 0.5-1.5 A.
If the compressor starts, but turns off after a few seconds, the problem may be:
- Faulty thermostat (does not give a signal to work).
- Stuck fan (if it is in the model).
- Low voltage in the network (less than 200V).
⚠️ Attention: If the compressor does not start, but the relay clicks every 5-10 seconds, this is a sign turn-to-turn short circuit in the windings. In this case, replacement will be required. compressor.
Connection features for different brands of refrigerators
Although the operating principle of the relay is the same, the design features may differ. Let's consider the nuances for popular brands:
| Refrigerator brand | Relay type | Connection features | Frequent problems |
|---|---|---|---|
| Atlant, Biryusa | Induction (RTK-X, DHR) | The terminals are located vertically. The starting capacitor is often located separately. | Oxidation of contacts due to high humidity. |
| Indesit, Stinol | Combined (starting + protective) | Wires are often marked with color: red - R, brown - S. |
Relay overheating due to poor ventilation. |
| Samsung, LG | Electronic (posistor) | The relay is integrated into the control board. Connection only according to the diagram! | Failure of the posistor during voltage surges. |
| Liebert, Whirlpool | Electronic with a separate protective unit | Required fine adjustment of the operation current. | False protection trips at low voltage. |
For refrigerators Samsung with the system No Frost it is important to check not only the relay, but also defrost timer - its malfunction may simulate a relay breakdown.
When is it better to contact the to the technician
Not all breakdowns can be repaired yourself. Contact a specialist if:
- 🔧 The compressor does not start, but the relay and windings are working (the control board may be damaged).
- ⚡ After connecting, the relay burns out or smokes (problem in the circuit). power supply).
- ❄️ The refrigerator turns on, but does not freeze (freon leak or capillary tube clogged).
- 📉 The voltage in the network is unstable (a stabilizer is required).
The cost of replacing the relay in the service center is 1500-3000 rubles (depending on the model). If you are not confident in your skills, it is better to pay for repairs than to risk an expensive compressor.
⚠️ Attention: In refrigerators with electronic control (for example, Bosch KGE39XW2AR), replacing the relay may require reflashing the board. Without special equipment, this cannot be done at home.
FAQ: Frequently asked questions about connecting relays
Is it possible to connect a relay from one refrigerator to another?
Only if the compressor models are the same. For example, the relays. from Atlant MXM-170 is suitable for Biryusy-18, since they use the same compressor Danfoss NL10. Before replacing, compare the markings on the compressor housing.
What to do if the wires on the relay are burnt?
The burnt wires must be cut to pure copper, cleaned and reconnected. If the length does not allow, extend the wire with a piece of the same cross-section, soldering and insulating the connection with heat shrink. Do not use. twists!
How to check if the relay is working?
Disconnect the relay from the compressor and ring the contacts:
- Between
CandSthere should be a resistance of ~30 Ohms (start winding). - Between
CandR— ~15 Ohm (working winding). - Between
LandCin the normal state - open (infinity).
If the values are different, the relay is faulty.
Why does the relay click, but the compressor does not start?
There are several reasons:
- Faulty Starting capacitor (ring it - the resistance should drop from infinity to zero).
- The compressor is jammed (try turning its shaft manually by turning off the power).
- Low mains voltage (less than 190V).
Do you need to solder the wires when connecting?
No, most relays are used screw or spring type terminals. You only need to solder if the contacts are damaged or the wires are too short for a normal connection.