A sudden stop of operation of the refrigerator Atlant often takes you by surprise, especially when food in the chamber begins to spoil. One of the most common causes of compressor failure is the failure of the start-up relay. This small but critical element is responsible for starting the motor and protecting the windings from overloads. If you hear clicks, the hum of the motor without subsequent startup, or the complete silence of the unit, the problem most likely lies in this particular unit.
Self-diagnosis of the relay allows you to save time and money on calling a technician, since the verification procedure is quite simple and does not require complex equipment. All you need is a basic set of tools and a multimeter. In this article, we will analyze in detail the algorithm of actions that will help determine the condition of the part and understand whether it needs replacement.
Design and principle of operation of the starting relay
The starting relay in refrigerators Atlant is an electromechanical switch mounted on the compressor housing. Inside the plastic case there is a coil, a movable core and a contact group. When voltage is applied to the motor windings, the current passes through the relay coil, creating a magnetic field that draws in the core and closes the contacts of the starting winding.
As soon as the compressor rotor reaches the required speed, the current in the circuit drops, the magnetic field weakens, and the spring returns the core to its original position, opening starting circuit. In parallel with the starting function, the device often acts as a heat sink, opening the circuit when the motor overheats critically. Failure to operate any of these mechanisms leads to the impossibility of starting or emergency shutdown of the equipment.
Modern models can use different types of relays, including posistor ones, which operate on the principle of changing resistance when heated. Understanding exactly what type is installed in your refrigerator is important for proper diagnosis. Visually, they may differ in the shape of the case and the number of contacts, but the principle of testing them remains similar.
What is the difference between an induction and posistor relay?
Induction relays use an electromagnet and a movable core to close the contacts. PTCs (solid-state) have no moving parts and work by heating a special crystal, which changes its resistance. PTC resistors are considered more reliable, but require time to cool down (3-5 minutes) before restarting the compressor.
External signs of a faulty protection relay
Before you begin disassembling and testing with a multimeter, you should pay attention to the behavior of the refrigeration unit. There are a number of characteristic symptoms that indicate problems with the trigger mechanism. Ignoring these signs can lead to more serious damage, including combustion of the compressor itself.
Most often, users are faced with a situation where the motor tries to start, makes a humming sound, but after a few seconds a click is heard and the operation stops. This is a classic symptom of stuck contacts or a failed coil. The relay housing may also heat up or a burning smell may appear, which indicates a short circuit inside the part.
- 🔊 The compressor hums for 5-10 seconds, then a shutdown click is heard.
- 🔥 The relay or compressor housing gets very hot when trying to start.
- ❄️ The refrigerator does not freeze, although the power indicators are on.
- 💥 When turned on, it knocks out the circuit breakers in the electrical panel.
If you notice that the refrigerator Atlant behaves in this way, further operation without diagnostics is prohibited. Prolonged attempts to start with a faulty relay create a huge current load on the motor windings, which can completely damage it.
Removing the relay from the body compressor
To carry out high-quality diagnostics, it is necessary to remove the relay from its seat. Before starting any work, it is absolutely necessary to turn off the power to the refrigerator by removing the plug from the socket. Safety when working with electrical appliances is priority number one.
Get to the bottom of the refrigerator where the compressor is located. Some models Atlant may require you to remove the rear protective panel or cardboard cover that is secured with screws or latches. The relay is usually placed directly on the three contact pins of the compressor and secured with a metal bracket or a plastic holder.
☑️ Safe dismantling algorithm
Be careful when Removing Parts: Old plastic housings can be fragile. If the relay is supported by wires, they must be carefully disconnected, having first remembered or photographed the connection diagram. Often the wires are simply removed from the terminals, but sometimes they can be crimped.
⚠️ Attention: Do not use excessive force when removing the relay. If the part does not budge, check to see if the retaining bracket has been left behind. A sharp jerk can damage the contact pins of the compressor itself, the repair of which will cost much more than replacing the relay.
Visual inspection and initial check
The removed relay should be carefully inspected in good lighting. Often external defects can immediately indicate the nature of the malfunction. Darkening of the plastic, melting of the case or the presence of soot inside are clear signs of overheating and short circuit.
Shake the part near your ear. If a clear knocking sound of a detached element is heard inside, it means that the mechanism is mechanically destroyed. In posistor relays, the housing is usually filled with compound or tightly closed, so it is more difficult to check the insides visually, but traces of burning on the contacts will be visible from the outside.
Pay special attention to the contact group. Oxidation or carbon deposits on the contacts can prevent the normal flow of current. In some cases, cleaning the contacts with fine sandpaper can temporarily restore functionality, but this does not guarantee a permanent solution to the problem.
| Symptom | Probable cause | Action |
|---|---|---|
| Melted body | Short circuit or overload | Replacement of the relay |
| Knock inside when shaking | Mechanical destruction of the core | Replacement of the relay |
| Soot on contacts | Sparking, poor contact | Cleaning or replacement |
| Cracks in the body | Impact, fall, aging of plastic | Replacing the relay |
If there are no visual defects, this does not guarantee serviceability. The internal winding of the coil could burn out without leaving external traces, or the posistor could lose its properties. Therefore, let's move on to instrumental diagnostics.
Diagnostics with a multimeter (continuity test)
The most accurate way to check the refrigerator relay Atlant is to use a multimeter in resistance measurement mode (Ohm). Switch the device to the 200 Ohm range or dialing mode. For induction relays, the test is carried out between the contacts corresponding to the input and output of the starting winding.
In normal condition, the coil resistance should be from 3 to 15 Ohms, depending on the specific relay model. If the device shows one (infinity), it means that there is a break in the winding. If the resistance is close to zero, an interturn short circuit has occurred. In both cases, the part must be replaced.
For posistor relays, the technique is slightly different. Resistance should be between 15-50 ohms at room temperature. The peculiarity of a posistor is that after short-term heating (for example, with a hairdryer), its resistance should increase sharply to thousands of ohms. If this does not happen, the element is faulty.
- ⚙️ Set the multimeter to resistance measurement mode.
- 🔌 Connect the probes to the corresponding relay contacts.
- 📉 Record the readings: normal, open or shorted.
- 🔥 (For posistors) Heat the element and check the increase in resistance.
It is also important to check the thermal protection if it is built into the relay body. Ring the contacts of the thermal relay - the resistance should be close to zero (the circuit is closed). If the circuit is open when the engine is cold, the thermal protection is faulty.
Replacement and testing after repair
If diagnostics confirmed a malfunction, you need to purchase a new analogue. Relays are selected strictly according to the compressor model or the catalog number of the old part. There are no universal solutions here, since the starting currents and winding characteristics of different motors Atlant may differ.
Installation of a new relay is carried out in the reverse order of removal. Make sure that the part is seated tightly on the contacts until it stops, and that the fixing bracket securely holds the case. If the relay has a specific orientation (top/bottom), follow the markings on the body, usually the arrow or inscription UP should face up.
⚠️ Attention: Incorrect installation of the relay (upside down) can lead to the mechanism not working or, conversely, not opening the circuit, which will cause the trigger to burn out compressor windings.
After assembly, turn on the refrigerator. A normal start should be accompanied by a confident hum of a running engine without long pauses or repeated clicks. The compressor should pick up speed within 1-3 seconds. If after 10-15 minutes of operation the relay does not heat up excessively, but the chambers begin to get cold, the repair can be considered successful.
Frequently asked questions (FAQ)
Is it possible to start a refrigerator without a relay?
Technically, you can start the compressor by applying voltage directly to the starting winding, but do this It is strictly not recommended for continuous use. Without a starting relay, the engine will not be able to switch to operating mode on its own, and without thermal protection it will quickly burn out if overloaded or jammed.
How much does a new relay cost for Atlant?
The cost of a starting relay varies depending on the type (induction or posistor) and the manufacturer. On average, the price ranges from 300 to 800 rubles. Original spare parts may cost more, but Chinese analogues are often not inferior in reliability if selected correctly.
Why does a new relay burn out after a short time?
If a new relay fails quickly, the reason may not be in it, but in the compressor itself. An interturn short circuit in the motor windings creates an increased current, which melts the relay contacts. Also, the cause may be unstable voltage in the network or a malfunction of the thermostat.
How to distinguish a posistor relay from an induction relay?
Induction relays are usually heavier, have a movable core (audible when shaking) and are often marked with the letters RT, P-1. PTC resistors are lighter, have no moving parts, and are often marked MRP or resistance designation in Ohms. Also, posistors require time to cool down before restarting.