Owners of refrigeration equipment are often faced with a situation where the compressor stops starting or makes a characteristic click, after which the unit goes silent. In most cases, the cause of such a malfunction is the failure of the start-up relay, which is responsible for starting the engine. Understanding where is the relay on the Pozis refrigeratoris the first and most important step for self-repair or competent diagnostics before calling a technician.
Refrigerators Pozis, like many other domestically produced models, have a classic design where the main electrical components are located in close proximity to the compressor. This was not done by chance: this arrangement simplifies maintenance and reduces energy losses during current transmission. However, in order to get to the required part, you need to know the exact sequence of actions and precautions, since the work is carried out with high voltage electricity.
In this article we will analyze in detail the design of the lower part of the refrigerator, how to identify a fault in the relay, and also consider the nuances of replacing this unit. You will learn how to distinguish a relay failure from other problems with the motor and what tools will be needed to carry out the work. The starting relay on Pozis models is often combined with a thermal protector, which makes this unit critical for the safety of the entire system.
Design and location of the compressor unit
To find the relay, you need to visually Inspect the lower back of the refrigerator. This is where the compressor metal “barrel” is located, which is the heart of the cooling system. The relay is mounted directly on the terminals (contacts) of this compressor. On refrigerators Pozis access to this area is usually open, but can be closed with a decorative cover or a metal sheet that needs to be carefully removed.
The device itself is a black or white plastic case, placed on three pins extending from the motor housing. Inside this housing there are contacts, springs and a bimetallic strip. The design may vary depending on the model year and the type of engine installed. Often there is a combined starting and thermal relay, which performs a dual function: it starts the motor and protects it from overheating.
It is important to understand that the arrangement of the elements may vary slightly depending on the series. For example, single compressor models have easier access than dual compressor systems where the relays are located on different sides or at different levels. Before starting any manipulations, make sure that you see the electrical unit and not the filter drier or condenser.
⚠️ Attention: Before removing any protection or touching electrical components, be sure to disconnect the refrigerator from the power supply! Residual voltage in the capacitors or accidental activation can lead to serious electric shock.
Symptoms of a faulty start relay
You can determine that the problem lies in the relay by the characteristic signs of the refrigerator. Most often, owners notice that the unit is hummingbut does not generate cold. The engine tries to start, makes a low-frequency hum, and then there is a loud click and everything goes quiet. After some time, the cycle repeats. This is a classic symptom of sticking contacts or failure of the starting winding inside the relay.
Another sign may be a complete lack of reaction from the refrigerator when plugged in, although the indicators are on. In this case, the thermal relay could burn out, which broke the circuit due to overload. If you hear a burning or plastic smell coming from the bottom of the cabinet, this also indicates overheating of the electrical components, among which the relay is the most likely to fail.
Sometimes the refrigerator works fine, but the compressor gets very hot. This may indicate that the relay does not turn off the starting winding after the engine starts, and it continues to idle, consuming excess current. This condition is dangerous because it can lead to combustion of the compressor itself, the replacement of which is not economically feasible.
Dismantling and visual inspection of the part
The process of removing the relay on refrigerators Pozis is quite simple and does not require complex tools. After turning off the power and removing the rear protective panel (if there is one), you will see the compressor with copper tubing and an electrical bundle of wires going to it. The relay is usually fixed to the motor terminals and can additionally be held on a metal bracket or spring clip.
For dismantling, you must carefully remove the fixing bracket, if present. Then grab the relay housing and pull it towards you with light rocking movements. It should come off the contact pins of the compressor. Do not use excessive force to avoid damaging the fragile contacts or breaking off the wires leading to the power plug.
After removing the device, perform a thorough visual inspection of it. Shake the relay near your ear: if you hear a knock inside, it means the mechanical part is damaged or the core has come off. Inspect the case for melting, blackening or cracks. The presence of carbon deposits on the contacts inside (if it is possible to look) indicates a spark has slipped and a commutation failure.
☑️ Procedure for dismantling the relay
Types of relays used in Pozis refrigerators
In refrigeration equipment Pozis Various types of starting devices are used depending on the power of the compressor and the year of manufacture of the model. Understanding the type of relay you have will help you choose the right replacement and understand how it works. The main division occurs into electromagnetic and posistor devices, each of which has its own design features.
Electromagnetic relays operate due to the appearance of a magnetic field in the coil when current passes through the working winding. This field draws in the core, which closes the contacts of the starting winding. As soon as the engine picks up speed, the current drops, the core, under the influence of gravity (or a spring), lowers, opening the circuit. Such devices are often labeled RTP, RTK or ROM.
Posistor relays (for example, series PTC) use the properties of the semiconductor material to sharply increase resistance when heated. When turned on, a cold posistor passes current to the starting winding, heats up in seconds and actually turns it off, switching to high resistance mode. They are more reliable, have no moving parts and are less sensitive to the position of the refrigerator.
| Relay type | Principle of operation | Characteristic signs of failure | Marking examples |
|---|---|---|---|
| Electromagnetic | Retraction of the core by current | Loud click, contact sticking | RTK-1, RTP-2 |
| Posistor (PTC) | Change in resistance when heated | No click, silence when starting | PTC 12-18, 35-100 |
| Thermal (protection) | Opening by bimetallic plate | Frequent motor shutdown | TZ-1, 17MR |
Is it possible to repair the relay?
Theoretically, an electromagnetic relay can be disassembled and the contacts can be cleaned, but the service life of such repairs is extremely short. PTC relays are disposable and cannot be restored. It is cheaper and safer to buy a new original unit.
Instructions for checking performance
Before buying a new part, it makes sense to check the old one, especially if you have a multimeter. Testing the contacts allows you to identify an open circuit or short circuit. For posistor relays, the test consists of measuring the resistance: in a cold state it should be low (tens of Ohms), and when heated (if current is applied) it should go to infinity.
Electromagnetic relays are checked for mechanical jamming of the core and integrity of the coil. The coil resistance should be within normal limits (usually from 10 to 50 Ohms depending on the model). If the multimeter shows one (open) or zero (short circuit), the part is faulty. It is also important to check the thermal relay: in a cold state, its contacts should ring short.
There is a “connection” test method, but it requires high qualifications and compliance with safety measures. A short-term supply of power to the compressor with a bypass relay (jumper) can show whether the motor itself is alive. However, this is strictly not recommended for beginnersas you can burn the motor windings or create a short circuit in the apartment wiring.
⚠️ Attention: The technical characteristics of the relay (rated current, connection type) must strictly correspond to the parameters of your compressor. Installing a relay with a large current can lead to burnout of the motor, and with a smaller one - to constant false shutdowns.
Replacement and commissioning
Replacement of relays on refrigerators Pozis is carried out in the reverse order of dismantling. Make sure that the new device has identical markings or is a complete functional analogue. Push the relay onto the compressor pins until it stops, observing the orientation (up/down, arrows on the body). If the relay has a clamping bracket, be sure to install it in place to securely hold it in place.
Connect the power wires to the appropriate terminals on the relay. They are usually color coded or labeled (L, N, Start, Run). It is difficult to mix up the wires due to the shape of the connectors, but double-checking using the diagram photographed earlier will not be superfluous. Make sure that the wires do not touch the hot copper tubes of the compressor.
After assembly, plug in the refrigerator. It is considered normal for the relay to click once and start the motor, which should run smoothly, without vibration or hum. After some time, the compressor should turn off on its own when it reaches the desired temperature. If the cycle repeats or the motor hums, immediately turn off the power and check for correct installation.
How to determine whether the compressor or just the relay has burned out?
If after replacing a working relay the situation does not change (clicking and silence), test the windings of the compressor itself with a multimeter. The resistance between the contacts should be different (the starting resistance is higher than the operating resistance), and between the case and the contacts it should be infinite. If the resistance between the contacts is zero or the housing “rings,” the compressor is faulty.
Can a relay be used from another refrigerator?
It can only be used if the characteristics completely match: rated current, connection type (2 or 3 contacts) and device type (electromagnetic/posistor). Visual similarity does not guarantee performance. It is better to look by the catalog number indicated on the case.
Why does the relay burn out again?
Repeated combustion of the relay often indicates problems with the compressor itself (stiff running, interturn short circuit), voltage surges in the network or poor contact in the wiring. Also, the reason may be the installation of a relay with an inappropriate rated current that cannot withstand the starting load of the engine.