A sudden stop of the compressor is always stressful for the owner of household appliances. When the refrigerator Indesit stops freezing and the engine does not start or makes only a short click, the first thing that comes to mind is a serious breakdown. However, often the problem lies in a small but critical part - the start relay. It is this element that controls the supply of voltage to the motor windings at the time of start.
Diagnostics of this part does not require deep engineering knowledge, but requires basic skills in working with electrical appliances and the presence of a simple measuring instrument. The multimeter allows you to accurately determine the integrity of internal circuits and contacts. Correctly checking the Indesit refrigerator relay with a multimeter will help you save a significant amount on calling a technician and buying an expensive compressor if it turns out that the engine is working.
In this article we will analyze in detail the algorithm of actions, from dismantling to final resistance measurements. You will learn how to distinguish a burnt coil from stuck contacts and what values on the tester screen are considered normal. A competent approach to repair will extend the life of your household appliance and restore self-confidence.
The principle of operation and types of Indesit starting relays
The starting relay in refrigerators Indesit performs the function of a circuit breaker that supplies current to the starting winding of the engine only at the moment launch. As soon as the compressor rotor reaches the required speed, the device opens the starting winding circuit, and the motor continues to operate on the main winding. Violation of this process leads to a hum and subsequent shutdown of the unit by the thermal protector.
In the equipment of this brand, two types of devices are most often found: posistor and electromagnetic. Posistor models, such as series PTC, work due to the property of the ceramic element to heat up and increase its resistance, actually opening the circuit. Electromagnetic relays, often designated as RCT or R600, use a movable core that is drawn into the coil when the starting current is applied and mechanically opens the contacts.
⚠️ Attention: Visually, the types of relays may be similar, but their internal structure and wiring principle are different. By mixing up the diagnostic method, you can draw the wrong conclusion about the serviceability of the part.
For correct diagnostics, you need to know exactly what type is installed in your refrigerator. Typically, the markings are applied to the body of the relay itself or indicated in the technical documentation for the refrigerator model. Understanding the physics of the process helps to quickly interpret multimeter readings and not waste time on unnecessary manipulations.
- 🔌 PTC relays do not have moving mechanical parts in the control circuit, which makes them more durable, but sensitive to voltage surges.
- ⚙️ Electromagnetic devices rely on the mechanical movement of the core, which can rust over time or jam.
- 📉 The resistance of the starting winding is always lower than that of the working winding, which is a key parameter when taking measurements.
Preparation for diagnostics and safety precautions
Before starting any manipulations with the electrical part of the refrigerator, it is necessary to ensure complete safety. The very first step is to disconnect the device from the power supply. Unplug the plug from the socket and make sure that access to it will not be blocked during operation. This is fundamental ruleignoring which may result in electric shock.
Next, you should prepare the workplace and tools. You will need a multimeter (tester), screwdrivers (usually Phillips and flathead), pliers and possibly a knife for stripping contacts. If the relay is located in a hard-to-reach place, you may need to remove the back panel of the refrigerator or dismantle the compressor compartment completely.
☑️ Checklist for preparing for repairs
Inspect the wires for melting or damage to the insulation. If you find blackened areas of the wiring, this may indicate a short circuit or overheating at the contact point. In such cases, simply replacing the relay may not solve the problem completely; restoration of the wiring will be required.
Removing the relay from the refrigerator compressor
Access to the relay is through the back wall of the refrigerator, where the compressor unit is located. In models Indesit the relay is often covered with a plastic casing or metal cover, which is secured with latches or screws. Carefully remove the protection, being careful not to damage the plastic clips, which can be fragile on old refrigerators.
The relay itself is placed directly on the contact group of the compressor. It is secured either by a tight fit or by a metal clamp. If a staple is used, it must be carefully pressed out with pliers. Do not use excessive force to avoid breaking the mounting lugs on the relay body or damaging the compressor tubes.
After removing the retaining element, the relay can be easily removed from the compressor pins. However, there are electrical wires connected to it that also need to be disconnected. In some models, the wires are inserted into terminals on the relay body, in others they can be soldered (which is less common in modern models). To remove the terminals, use a thin screwdriver to press the clips, or just gently pull them if they are held by friction.
- 📸 Take a photo of the general view of the assembly before disassembling - this will help with reassembly.
- 🔧 Use insulated tools to avoid accidentally shorting the contacts if there is still charge in the capacitors.
- 🧹 Clean the area around the compressor from dust and cobwebs before starting work so that debris does not get inside the mechanism.
External inspection and search for visible defects
Before taking up the multimeter, conduct a thorough visual analysis of the removed relay. Often a breakdown can be determined without instruments. Shake the relay near your ear: if you hear a ringing or knocking sound of detached parts inside, it means that the device is destroyed from the inside and requires replacement. This is typical for ceramic posistors, which can crumble due to overheating.
Inspect the case for melting, blackening or swelling. The presence of soot inside the housing or on the contacts indicates that sparking or arcing has occurred inside. If plastic parts are deformed from high temperature, further operation of such an element is impossible and dangerous.
Why does the relay heat up?
The relay heats up during operation, but critical overheating is usually caused by frequent attempts to start the compressor (cycling). This occurs if the compressor cannot start due to low voltage, a jammed motor, or a malfunction of the relay itself. Constant heating leads to degradation of materials and eventual combustion.
Check the condition of the contacts. They must be clean, without green deposits of oxides and soot. If the contact pads are blackened, this increases the contact resistance, which leads to a voltage drop and inefficient operation of the motor. In some cases, the contacts can be cleaned, but if the metal is burnt out, only replacement will help.
Instrumental check with a multimeter
To take measurements, switch the multimeter to the resistance measurement mode (Ohm, denoted as Ω). Select the minimum range (usually up to 200 or 2000 Ohms). Before measuring, short-circuit the probes to each other to make sure that the device is working properly - the screen should show zero or a value close to it.
Checking a posistor relay (PTC) is carried out by making a continuity test between the main contacts. The resistance of a working posistor at room temperature should be low, usually in the range of 10–50 Ohms (the exact value depends on the model, for example, for Indesit C132G it may differ from Indesit DF 520). If the multimeter shows one (infinity) or zero (short circuit), the element is faulty.
For electromagnetic relays the procedure is more complicated. It is necessary to ring the coil and check the mobility of the core. The coil resistance should also be within tens of ohms. It is important to check whether the contacts open at rest and close when voltage is applied (to fully test an electromagnetic relay, it is sometimes necessary to apply a 220V current, which is dangerous to do without experience, so we often limit ourselves to testing the coil and visually inspecting the contacts).
| Relay type | Normal resistance (Ohm) | Fault symptom | Action |
|---|---|---|---|
| Posistor (PTC) | 10 - 60 Ohm | ∞ (Open) or 0 (Short circuit) | Replacement |
| Electromagnetic | 10 - 100 Ohm (coil) | Contacts do not open | Replacement or cleaning |
| Thermal (protection) | 0 Ohm (closed) | ∞ (Open circuit) | Replacement |
| Combined | Depends on the circuit | No click | Complex diagnostics |
Diagnostics of compressor windings through a relay
Often the problem lies not in the relay itself, but in motor windings, and the relay only signals this. Removing the relay gives you access to three contacts on the compressor. To check the engine, you need to know the pinout. Usually the contacts are arranged in a triangle: one on top and two on the bottom (or vice versa, depending on the model Indesit).
Use a multimeter to ring pairs of contacts. Between the working and starting windings, the resistance should be the sum of the resistances of each winding separately. For example, if there is 20 ohms between the top and bottom left, and 40 ohms between the top and bottom right, then between the two bottom ones there should be about 60 Ohm. If somewhere the multimeter shows infinity, there is a break in the winding, if zero there is an interturn short circuit.
It is also necessary to check the breakdown on the housing. Press one probe of the multimeter to any contact of the motor (or a cleaned place on the compressor body), and the second to the copper tube or metal body of the refrigerator. The device should show infinity. If there is any. some resistance means the motor is “broken” and cannot be operated.
⚠️ Attention: If a breakdown of the windings on the body is detected, it is strictly forbidden to turn on the refrigerator! diagnostics showed that the relay is faulty, it needs to be replaced. You need to buy a similar model. The original number is usually stamped on the case (for example,
Replacing and selecting a new relay
If the diagnostics showed a faulty relay, it must be replaced. You need to buy a similar model. The original number is usually stamped on the case (for example, Indesit 146300 or PTC 18CL. If the original cannot be found, you can select a universal relay, but strictly ensuring that the compressor power (indicated in Watts or Amperes) and the type of refrigerant (R600a) correspond. or R134a).
Installation of the new element is carried out in the reverse order of removal. The relay is pushed onto the contacts of the compressor until it stops. It is important that it sits tightly and evenly, without distortions. After this, the wires are connected according to the previously made diagram or photograph. Make sure that the terminals are put on tightly and do not loose.
Is it possible to use a relay from another one? brand?
In some cases, relays from Atlant or Stinol refrigerators may fit Indesit if the mounting dimensions and electrical characteristics (operation current) match. However, it is better to use original spare parts or proven analogues to avoid problems with starting the compressor.
After assembly, turn on the refrigerator. If you did everything correctly, after a few seconds you should hear a characteristic click. the compressor will start. If there is no click or the engine hums and immediately turns off, the test must be repeated, paying attention to the contacts and wiring.
Frequently asked questions (FAQ)
Is it possible to repair a burnt relay or just replace it?
In 99% of cases, the relay only need to be replaced. The internal structure (ceramic posistor or coil with contacts) is not designed for repair at home. An attempt to disassemble and solder the contacts, as a rule, leads to a temporary effect or a fire hazard. The cost of a new element is low, so repairs are not economically feasible.
Why does a new relay burn out immediately after installation?
If the new relay burns out instantly, the reason is not the compressor itself (interturn short circuit, jamming) or there are problems with the electrical circuit (short circuit in the wiring). Also, the cause may be unstable voltage in the network. In this case, an in-depth diagnosis of the motor is required.
How to distinguish the Indesit relay. from other manufacturers?
Indesit relays often have a specific housing shape and contact arrangement characteristic of Danfoss or Embraco compressors that are used in these refrigerators. The key marker is the marking on the housing and the type of connector. Always visually compare the old and new part before purchasing.
Is it dangerous to turn on a refrigerator without a relay?
Yes, this is extremely dangerous. Without a starting relay, the compressor will not be able to start correctly: the starting winding will remain energized, which will lead to rapid overheating and combustion of the engine. In addition, the thermal protection may not work in time, which can lead to a fire.