How to properly connect the Pozis refrigerator relay: step-by-step instructions with diagrams

Brand refrigerators Pozis are known for their reliability, but even they are not immune from breakdowns. One of the common problems is the failure of the start-up relay or thermostat. If the compressor does not start, hums but does not freeze, or the refrigerator turns off a few seconds after starting, the relay may be the culprit. In most cases, you can replace it yourself, without resorting to the services of a specialist.

In this article we will look at how to properly connect a relay on a refrigerator Pozis, including models Pozis-16KSh, Pozis-18KSh, Pozis-20 and other popular series. You'll learn what tools you'll need, how to read a wiring diagram, where the terminals are located on the compressor, and how to avoid common installation mistakes. We will also look at the differences between start-protection relay and thermostat - they are often confused, although they have different functions.

If you have never repaired refrigerators, do not worry: the process of connecting the relay does not require special skills. The main thing is to observe safety precautions and follow the instructions. At the end of the article you will find answers to frequently asked questions and tips for diagnosing faults.

What is a relay in a refrigerator and why is it needed?

A relay in a refrigerator Posis performs two key functions:

• 🔹 Starting —supplies voltage to the starting winding of the compressor at the time of start-up in order to overcome the inertia of the rotor.
• 🔹 Protective - turns off the power if the current in the compressor windings exceeds the permissible values (for example, when the motor is jammed).

Without a working relay, the compressor will either not start at all or will work intermittently. In refrigerators Pozis most often two types of relays are used:

• 🔧 Tablet (RTK-X) - a compact round-shaped relay, installed directly on the compressor. Used in models with compressors Danfoss, Secop.
• 🔧 Boxed (RTP-1, DHR) —a rectangular relay with terminals, mounted on the frame of the refrigerator next to the compressor. Found in old models Pozis and refrigerators with compressors Atlant.

It is important not to confuse the start-up relay with thermostat (thermostat). The thermostat is responsible for maintaining the set temperature and controls the compressor on/off, while the relay ensures its correct start and protection. If the refrigerator does not freeze, but the compressor hums and heats up, the problem is most likely in the relay. If the compressor does not turn on at all, check the thermostat.

Tools and materials for connecting the relay

Before starting work, prepare everything you need. You will need:

• ⚡ New relay - must correspond to the compressor model. For Pozis relays are most often suitable RTK-X, DHR-5M, RTP-1. Check the markings on the old relay or compressor.
• 🔧 Phillips and flathead screwdrivers — for dismantling the panel and fastenings.
• 📏 Multimeter —to check the integrity of the compressor windings and relay contacts.
• 🔌 Pliers or side cutters —for careful removal terminals.
• 🧲 Magnet or marker —to avoid mixing up the wires when disconnecting.
• 🧴 Insulating tape or heat shrink tube —to insulate contacts.

If you buy a relay separately, pay attention to its characteristics:

Before purchasing a relay, take a photo of the old one or write down its markings. For example, on the relay RTK-X there may be an inscription like RTK-X 103 220-240V 50Hz. If you are not sure of the choice, show the photo to the seller - he will help you choose an analogue.

Preparing the refrigerator for replacing the relay

Before starting work, be sure to unplug the refrigerator and defrost it. This is necessary for safety and ease of access to the compressor. Let the refrigerator sit for 1-2 hours to allow the condensation to evaporate.

Next, follow these steps:

1. Remove the lower rear panel of the refrigerator (if equipped). It is usually secured with latches or screws.
2. Move the refrigerator away from the wall to gain access to the compressor. It is located at the bottom and looks like a black metal cylinder with tubes.
3. You will see a relay on or near the compressor. In models Posis it can be:

• 🔘 Attached directly to the compressor (tablet).
• 🔘 Installed on the frame next to the compressor (box relay).
• 🔘 Connected via a terminal block (in new models).

Before disconnecting the wires, take a photo of their location or mark it with a marker. Pay attention to the colors of the wires - this will help you connect the new relay correctly. Typical connection diagram for refrigerators Posis:

• 🔴 Red or orange —starting winding (S).
• 🔵 Blue or black —working winding (R).
• ⚪ White or yellow — common wire (C).

Relay connection diagram on the Pozis refrigerator

The connection diagram depends on the type of relay and the compressor model. Below are the two most common diagrams for refrigerators Pozis.

1. Connecting a relay tablet (RTK-X)

The relay tablet is installed directly on the compressor and has three output:

• 🔌 C (Common) - common contact.
• 🔌 S (Start) - starting winding.
• 🔌 R (Run) - working winding.

Connection diagram:

Compressor
┌───────────┐
│ C   S   R │
└─────┬─────┘
│
┌─────┴─────┐
│ Relay │
│ RTK-X │
└─────┬─────┘
│
┌─────┴─────┐
│ 220V │
└───────────┘

Connection order:

1. Connect the wire from the network (phase) to the contact C on the relay.
2. Connect the contact S on the relay with the starting winding of the compressor.
3. Contact R on the relay, connect to the working winding of the compressor.

2. Connecting a box relay (DHR, RTP-1)

The box relay has a terminal block with 4–5 contacts. Typical circuit for refrigerators Pozis with compressor Atlant:

┌───────────────────┐
│ Compressor │
│ C   S   R         │
└─────┬─┬─┬─────────┘
│ │ │
┌─────┴─┴─┴─────┐
│ Relay DHR-5M - input phase (220V).
│ 1   2   3   4│
└─────┬─┬─┬─────┘
│ │ │
┌─────┴─┴─┴─────┐
│ 220V (phase) │
│ Zero │
└───────────────┘

Decoding relay contacts DHR-5M:

• 🔢 1 — phase input (220V).
• 🔢 2 — output to the working winding (R).
• 🔢 3 — output to the starting winding (S).
• 🔢 4 — zero (common).

To check the correct connection, use a multimeter in continuity mode. Between contacts 1 i 4 there should be a resistance of ~20–50 Ohms (depending on the relay model). If there is no resistance, the relay is faulty.

How to check the relay with a multimeter?

Set the multimeter to the continuity mode (200 Ohms). contacts 1 and 4 of the relay - should show resistance. Then jump contacts 2 and 3 with a screwdriver: if the relay is working properly, you will hear a click and the resistance between 1 and 4 will become infinite.

Step-by-step instructions for connecting the relay

Now let's move on to practice. data-i="197">Unplug the plug from the socket and make sure that there is no voltage supplied to the compressor.

1. Disconnect the refrigerator from the network. Unplug from the socket and make sure there is no voltage being supplied to the compressor.
2. Remove the old relay. Carefully disconnect the wires, remembering their location. If the relay is mounted on clamps, squeeze them with pliers and remove the part.
3. Check the compressor. Make sure that there are no breaks or short circuits on its windings. To do this, test the contacts C-S, C-R and S-Rwith a multimeter. The resistance should be in the range of 10–50. Ohm.
4. Install a new relay. Connect the wires according to the diagram (see the previous section). If you are using a tablet relay, put it on the compressor so that the contacts coincide with the terminals of the windings.
5. Secure the relay. Make sure that it sits tightly on the compressor or is fixed to the frame. Check if the wires are loose.
6. Connect the refrigerator to the network. Turn it on and observe the operation of the compressor. It should start without any extraneous sounds and start pumping out cold after 1-2 minutes.

If after connection the compressor does not start or the protection is triggered (the relay clicks and turns off), possible reasons:

• ❌ Incorrect wire connection (check the diagram).
• ❌ Compressor malfunction (call windings).
• ❌ The relay does not match the compressor model (check the marking).

Typical errors. connecting the relay

Even experienced technicians sometimes make mistakes that lead to repeated breakdowns. Here are the most common ones:

1. Confused. wires. If you connect the starting and working windings in places, the compressor will not start or will overheat!
2. Using an incompatible relay. The relay from the refrigerator Atlant may not be suitable for Pozis with a compressor Danfoss. Check the markings.
3. Bad contact. Oxidized or loose terminals lead to heating and burning of the contacts. Strip the wires and tighten the connections tightly.
4. Ignoring the compressor test. If the compressor. is faulty (for example, jammed), the new relay will burn out immediately after connection.
5. Operation under voltage. Connecting the relay while the refrigerator is on can lead to electric shock or failure of electronic components.

To avoid errors, use this checklist:

⚠️ Attention: If after replacing the relay the compressor starts, but after a few seconds it turns off, this may indicate an interturn short circuit in windings. In this case, the compressor needs to be replaced.

Diagnostics of faults after connecting the relay

After replacing the relay, turn on the refrigerator and observe its operation:

• ✅ The compressor starts. without extraneous sounds.
• ✅ After 1-2 minutes the cold begins to build up.
• ✅ The relay does not click constantly (one click at startup is normal).

If something goes wrong, use the diagnostic table:

If you are not sure of the cause of the malfunction, do not take risks - contact a specialist. Repairing the compressor yourself or refilling freon requires special skills and equipment.

⚠️ Attention: Refrigerator parts Position may vary depending on the year of manufacture. If your model was manufactured before 2010, check the connection diagram in the technical documentation or on repair forums.

FAQ: Frequently asked questions about connecting the relay

Is it possible to replace a tablet relay with a boxed one?

Theoretically, it is possible, but you will need to re-solder the wires and adapt the fasteners. It is better to use a relay of the same type that was installed initially. If you decide to experiment, make sure that the rated current and voltage of the new relay correspond to the parameters of the compressor.

How to determine that the relay burned out, and not the compressor?

Turn off the refrigerator, remove the relay and test the compressor windings with a multimeter:

• The resistance between C-R and C-S should be 10–50 Ohm.
• The resistance between R-S must be the sum of the two previous values.

If the windings are in order, the problem is in the relay. If there is no resistance or is zero, the compressor is faulty.

What to do if a new relay is immediately available. burnt out?

This is a sign of a short circuit in the compressor or overload. Possible reasons:

• Interturn short circuit in the windings.
• Judgement of the compressor shaft.
• The voltage in the network is too high. (more than 240V).

Check the compressor with a multimeter and measure the voltage in the socket. If the compressor is faulty, it will have to be replaced.

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

In most cases, no. which ensure reliable contact. It is worth soldering the wires only if the terminals are damaged or oxidized. In this case, use a soldering iron with a power of no more than 40 W and rosin to protect against corrosion.

Where to buy a relay for a Pozis refrigerator?

The relay can be found:

• In spare parts stores refrigerators (for example, Rembytekhnika, Holod-Service).
• On marketplaces (Yandex Market, Ozon, Wildberries) - search by relay model.
• On repair forums they often sell used parts in good condition.

The average price of a new relay is from 300 to 1000 rubles, depending on the type.