A sudden stop Indesit refrigerator often becomes an unpleasant surprise, especially if the food in the chambers has already begun to deteriorate. One of the first components that fails and blocks the engine from starting is the start-protection relay. This small but critical element is responsible for supplying voltage to the motor windings and protecting it from overheating. Understanding how this system works will allow you to quickly determine the cause of the breakdown without calling a technician.
Symptoms of a malfunction usually manifest themselves in a characteristic click, after which the compressor either does not start at all, or runs for only a few seconds and turns off again. In some cases, the unit may hum, but no cold is produced. Compressor relay - this is a consumable item that wears out over time, and its replacement is a standard procedure for repairing household appliances. In this article, we will analyze in detail the algorithm for diagnosing and restoring the functionality of your refrigerator.
Design and principle of operation of the start-up relay
To correctly carry out diagnostics, you need to understand the physical principle of operation of this unit. Refrigerators Indesit most often use posistor or induction relays mounted directly on the compressor housing. The main task of the device is to briefly supply current to the starting winding of the engine to create torque, and then turn it off when the rotor reaches the required speed.
In parallel with the starting function, the device acts as a thermal fuse. Inside the case there is a bimetallic plate that opens the circuit when the permissible temperature or current is exceeded. If starting relay faulty, the compressor may try to start indefinitely, which leads to severe heating and eventual combustion of the windings. Therefore, timely checking of this element is critical to saving an expensive motor.
Why does a relay often fail?
Frequent power surges in the network and natural wear of the contact group lead to sticking or burning of the contacts inside the relay. Also, the cause may be aging of the posistor, which ceases to correctly change its resistance when heated.
Visual diagnostics and external signs of failure
Before picking up measuring instruments, you should conduct a thorough external inspection. Often the problem is visible to the naked eye. Unplug the refrigerator, move it away from the wall and reach the compressor at the bottom rear of the unit. Carefully remove the protective plastic casing to gain access to the electrical part of the motor.
Pay attention to the condition of the wires and the relay body itself. If you notice traces of soot, melted plastic, or smell a burning smell, then relay malfunction obvious. Also, a sign of a problem may be oxidation of the contacts or their blackening. In some cases, the relay may simply crack from overheating or mechanical stress.
⚠️ Attention! If you see melted wires going to the relay, don't rush to just replace the part. It is necessary to check whether the compressor itself is short-circuited, otherwise the new relay will burn out after a few minutes of operation.
After removing the relay from its seat (usually it is simply removed from the compressor pins), shake it near your ear. If a rattling sound is heard inside, this means that the internal contact group or posistor is damaged. A working device should not make any sound when shaken. This is a simple but effective method of initial assessment.
Instrumental testing with a multimeter
For accurate diagnostics, you will need a multimeter (tester). This device will allow you to measure circuit resistance and determine the integrity of internal elements. Set the multimeter's resistance (Ohm) switch to the 200 Ohm limit. First, check the integrity of the thermal protection: ring the contacts corresponding to the input and output of the motor winding.
If the device shows one (infinity), then the circuit is broken and the relay requires replacement. If the resistance is close to zero, the protection is intact. Next you need to check the trigger mechanism. Depending on the type of relay (inductive or posistor), the technique may differ slightly, but the principle remains the same: the contacts must close and open in a certain order.
To test the posistor, you can apply a voltage of 12-14 volts to it from the power source (observing safety precautions), it should heat up and stop passing current, and after cooling it will start conducting again. However, at home it is easier to use the cold dialing method. The resistance of a working posistor is usually 20-40 ohms. If the device shows zero or infinity, the element is faulty.
Table of typical values and symptoms
For ease of diagnosis, the main parameters and symptoms of malfunctions are summarized in a table. Compare the readings of your device and the behavior of the refrigerator with the reference values. This will help you make a quicker decision about repairing or replacing the unit.
| Check parameter | Normal value | Fault symptom | Action |
|---|---|---|---|
| PTC resistor | 20–50 Ohm | 0 Ohm or ∞ (infinity) | Relay replacement |
| Thermal protection | 0 Ohm (closed) | ∞ (open circuit) | Replacing the relay |
| Sound when shaking | Absent | Rattling, knocking | Replacement relay |
| Appearance | Entire body, no burning | Melting, cracks, soot | Replacing the relay and checking the wiring |
It is worth noting that refrigerator compressor may not start not only due to the relay, but also due to a malfunction of the motor itself or the thermostat. However, if you hear the relay click when you turn it on, but there is no start, the probability of the problem in the starting device is more than 80%. Always check the presence of voltage at the input to the relay to prevent an open circuit.
Step-by-step instructions for replacing the relay
If diagnostics confirm a malfunction, it is necessary to replace it. This process does not require sophisticated equipment, but it does require attention and safety precautions. Make sure the refrigerator is completely unplugged. Any work with electrical components should be carried out only in the absence of voltage.
Remove the old relay by disconnecting the wires (if they are not on the terminals, but soldered, they will have to be carefully unsoldered, but in modern models Indesit connectors are more often used). Pay attention to the orientation of the part: it has a top and a bottom, which are indicated by arrows or inscriptions UP / TOP. Incorrect installation can lead to immediate failure of the new part.
☑️ Algorithm for replacing the relay
Install the new relay on the compressor pins until a characteristic click is heard. Connect the wires according to the previous photographs or color markings. Secure the metal bracket, if provided by the design. Now you can carefully put on the plastic casing and turn on the refrigerator. If you hear the smooth hum of a running motor and after 10-15 minutes cold appears in the chambers, then the repair was successful.
⚠️ Attention! Never leave your refrigerator running without the compressor protective cover in place. This may result in electric shock or foreign objects getting into moving parts.
Common mistakes when doing DIY repairs
Despite its apparent simplicity, beginners often make mistakes that can aggravate the situation. One of the most common is an attempt to “revive” an old relay by tapping or disassembling. Modern devices Indesit are often made in a non-separable sealed case, and any attempt to open them violates their geometry and properties.
Another mistake is installing a relay from another refrigerator model without checking the parameters. Although they may look similar visually, the current characteristics and pin lengths may differ. Using the wrong part will either prevent the motor from starting or burn out the compressor winding. Always use original spare parts or high-quality analogues with an identical article number.
Also, do not ignore the condition of the capacitor if it is in the circuit. Some circuits have a capacitor connected in parallel with the starting winding, which helps create a phase shift. If it is swollen or has lost capacity, even a working relay will not be able to start the engine. Checking the capacitor requires a special device, but you can visually assess its integrity.
Prevention and service life of equipment
The service life of the start-up relay directly depends on the operating conditions of the refrigerator. Frequent voltage drops in the electrical network are the main enemy of electrical engineering Indesit. To extend the life of the compressor and its components, it is recommended to use a voltage stabilizer or surge protector, especially in houses with old wiring.
Regular cleaning of the back wall of the refrigerator from dust and animal hair also helps to better cool the compressor. If the motor overheats, the thermal protection of the relay is activated more often, which accelerates its wear. Make sure that the gap between the back wall of the refrigerator and the furniture is at least 5-10 cm for free air circulation.
Is it possible to repair the relay yourself?
Theoretically, if the relay is dismountable, you can clean the contacts or replace the posistor. However, in practice, the service life of such repairs is extremely low, and the risk of fire or compressor breakdown is high. It is cheaper and safer to buy a new part.
If, after replacing the relay, the refrigerator stops cooling again or begins to behave strangely (frequently turns on and off), perhaps the problem lies deeper. This could be a freon leak, a malfunctioning thermostat, or wear and tear on the compressor itself. In such cases, further self-diagnosis can be dangerous and ineffective.
What relay article number is needed for an Indesit refrigerator?
The article number depends on the specific model of the compressor installed in your refrigerator. The most commonly used relays are the R6, RCT1 or PTC series. The exact part number is indicated on the nameplate of the relay itself. It is best to remove the old device and look for an analogue by its markings or photographs.
Why does the relay heat up during operation?
Slight heating of the relay body (up to 50-60 degrees) is a normal operating process, since current passes through it. However, if the housing heats up to temperatures at which you cannot touch it with your hand, or emits a burning smell, this is a sign of overload, poor contact or compressor malfunction.
Is it possible to start a refrigerator without a relay?
Theoretically, you can start the motor without a starting device by using a button to briefly supply current to the starting winding, but this is extremely dangerous and requires qualifications. Without thermal protection, the compressor can burn out in a matter of minutes if it jams. It is strictly prohibited to operate a refrigerator without a working relay.
How much does it cost to replace a compressor relay?
The cost of the part itself varies from 300 to 1000 rubles, depending on the manufacturer and type. If you contact a service center, the cost of calling a technician and work will be added to the price of the part, which in total can amount to 2000-3000 rubles. Self-replacement allows you to save on work.