The situation when the refrigerator stops cooling, and the compressor either is silent, or buzzes and clicks, but does not start, is familiar to many owners of household appliances. Often the cause of such a malfunction is the failure of starting relay a small but critical unit responsible for starting the engine. To understand whether a part can be repaired or requires complete replacement, it must be removed and disassembled. This action does not require complex professional tools, however, it requires strict adherence to safety precautions and accuracy when working with electrical components.
In this article we will analyze in detail the process of dismantling, disassembling and initial diagnostics of various types of relays. You will learn how to distinguish the starting winding from the working winding, what to look for when visually inspecting the contacts, and why in some cases disassembly may not be possible without damaging the housing. Correct diagnostics will allow you to save time and money by making an informed decision on further actions to restore the functionality of your refrigeration unit.
Diagnostics of faults before disassembly
Before taking a screwdriver, you need to make sure that the problem lies precisely in the relay, and not in the relay itself compressor or wiring. If the engine hums for a few seconds, then a click is heard and it goes silent - this is a classic symptom of a faulty starter or a jammed piston group. However, if the compressor is absolutely cold and does not make any sounds when turned on, the protection may have worked or the circuit has broken. thermal relay protection or a circuit break has occurred.
It is important to carry out an initial check with a multimeter without removing the part completely, if the design allows it. Check the contacts for short circuits or breaks. The absence of resistance where the contact should be, or, conversely, the presence of a short circuit between the insulated parts, will indicate the need for urgent replacement of the unit. Remember that diagnostics are half of a successful repair, and haste is unacceptable here.
⚠️ Attention: Before any work, be sure to disconnect the refrigerator from the power supply! Residual voltage in capacitors or accidental connection to the network can lead to serious electrical injury.
There are several signs that are highly likely to indicate a broken relay. Among them it is worth highlighting:
- 🔊 Characteristic crackling or clicking sounds immediately after turning on the refrigerator.
- 🌡️ The compressor heats up to a high temperature, but does not start.
- ⚡ Broken plugs or a tripped circuit breaker in the panel when trying start.
- ❄️ Lack of cold in the chambers when the engine is running (or trying to work).
Tools and preparation of the workplace
To disassemble the compressor relay efficiently, you will need a minimum set of tools that can be found in the arsenal of any home craftsman. The main tool will be flat-head screwdriver a small size, preferably with a thin tip to carefully pry up the plastic latches. You may also need pliers (pliers) to remove tight terminals and side cutters if you have to remove old sealant or insulation.
The work place should be well lit, since the internal elements of the relay are quite small. It is recommended to use a table with a flat surface covered with a clean cloth or dielectric mat to avoid losing small parts or damaging them. If you have one, be sure to prepare it in advance by setting it to resistance measurement mode (Ohm). flat screwdriver and pliers multimeter, be sure to prepare it in advance by setting it to resistance measurement mode (Ohm).
☑️ Ready for repair
It will not be amiss to have a solvent or alcohol on hand to clean contacts from oxides and carbon deposits, as well as fine sandpaper for grinding surfaces. If you plan to solder elements (which is necessary when repairing some types of relays), then the soldering iron and solder should also be ready for use. Organization of space is the key to ensuring that the process does not drag on for several hours due to the search for a lost screw.
Removing the relay from the compressor
The process of removing the relay begins with access to the back of the refrigerator. You need to move the unit away from the wall, providing free access to the compressor, which is usually located in the lower niche. Remove the protective cardboard or metal cover covering the engine compartment. In some models Indesit or Atlant it may be necessary to remove the back wall completely.
Find the relay block itself: it is mounted directly on the compressor terminals or on a bracket next to it. Carefully photograph the location of the wires before disconnecting them so as not to reverse the polarity during reassembly. This is especially important for models with two separate relays (starting and thermal), where an error can lead to a short circuit.
| Mounting type | Removal features | Risks |
|---|---|---|
| On latches | Pry off flat screwdriver | Break the plastic case |
| On the screws | Unscrew with a Phillips screwdriver | Tear off the thread or lose the screw |
| Interference fit | Carefully loosen | Damage the compressor leads |
When dismantling the unit, proceed without sudden movements. If the relay sits tightly on the compressor terminals, it must be carefully loosened from side to side, applying even force. Excessive pressure can break the ceramic motor terminal insulators, turning a simple repair into a complex compressor replacement. After removal, disconnect the wires, first remembering or marking them with a marker.
Disassembling the starting relay (RTK, R-1, R-600)
Most old-style starting relays, such as the popular ones RTK or R-600have a housing consisting of two halves held together with screws or plastic clips. If the device is held together with screws, simply remove them. If the case is assembled with latches (often found in newer models), you will have to show dexterity: insert a thin screwdriver blade into the joint of the halves and carefully turn it to disconnect the latches.
Inside you will see a copper coil, movable core and contact group. The basic principle of operation is that when voltage is applied, current passes through the coil, creating a magnetic field that draws in the core and closes the contacts of the starting winding. When the engine speed increases, the current drops and the contacts open. There may also be a capacitorcapacitor inside, which serves to smooth out inrush currents.
⚠️ Attention: There may be asbestos gaskets inside the relay (in older models). Try not to damage them or inhale dust when disassembling, as asbestos fibers are harmful to health.
When disassembling, pay attention to the condition of the contacts. If they are blackened or covered with soot, they need to be cleaned. To do this, use an eraser or fine sandpaper (“zero”). The surface should become shiny and smooth. If the contacts are melted or welded to each other, cleaning will not help - the entire part will need to be replaced. Also check the mobility of the core: it should move freely inside the coil without jamming.
What to do if the relay body is sealed?
Some modern relays (for example, in LG or Samsung refrigerators) have a non-separable sealed housing. There is no point in opening them forcibly (breaking them, sawing them) - the geometry will be broken, and it will not be possible to put them back together efficiently. Such devices can only be completely replaced with an analogue one.
Checking the thermal protection relay
Thermal relay is often structurally combined with the starting one or mounted next to common contacts. Its task is to break the compressor power circuit in case of overcurrent or overheating. Inside there is a bimetallic plate that bends under the influence of temperature and opens the contact. When disassembling this unit, be extremely careful: the bimetallic plate is very sensitive to mechanical deformation.
During a visual inspection, check the integrity of the nichrome heater filament (if it is in the design) and the condition of the contacts. Often the cause of false shutdowns is a weakened spring or contamination of the contact pair. Cleaning the contacts with alcohol and blowing with compressed air can restore the functionality of the unit.
To check the serviceability of the thermal relay, use a multimeter in dial mode. In a cold state, the contacts should be closed (resistance close to zero). If the device shows a break, the relay is faulty and requires replacement. You can also gently heat the relay body (not open contacts!) with a hairdryer or hold it in your hands, simulating overheating, and check whether the circuit opens. After cooling, the contacts should close again with a characteristic click.
Assembling and installing the relay in place
After diagnostics and repair (or replacement), it is necessary to assemble the device in the reverse order. Make sure that all internal elements are in place, the springs are not clamped, and the contacts do not touch the walls of the case if this is not provided for by the design. When connecting the halves of the housing, make sure that the wires are not pinched or damaged.
Installation on the compressor is carried out by lightly pressing until a characteristic click or tight fit occurs. Make sure that the relay sits strictly vertically (if the design provides for this), as some models only work in a certain position due to the gravitational core return mechanism. Connect the wires according to the photographs or diagram taken earlier.
- ✅ Check that all terminals are securely fixed - they should not be loose.
- ✅ Make sure that the relay body does not touch the metal parts of the refrigerator.
- ✅ Plug in the refrigerator and listen: the start-up should be soft, without loud noises clicks.
After connecting to the network, carefully observe the operation of the motor during the first 10-15 minutes. The compressor should work cyclically: turn on, cool the chamber and turn off. If you hear a hum, but there is no start, immediately disconnect the device from the network - perhaps the relay is selected incorrectly or the problem lies deeper, in the engine itself.
Is it possible to repair the relay if the coil is burned out?
It is almost impossible to rewind the starting relay coil at home due to the difficulty of selecting the wire of the required diameter and quantity turns. It is easier and more reliable to find a similar relay on the radio market or in a spare parts store.
Why does the relay heat up during operation?
Slight heating of the relay body (up to 50-60 degrees) is normal, since current passes through it. However, if the housing becomes so hot that it cannot be touched, this indicates a poor contact, a short circuit or a malfunction of the compressor.
How to distinguish a starting relay from a thermal one?
A starting relay is usually larger in size, contains a coil and a movable core. The thermal relay is more compact; a bimetallic plate is visible inside. They are often combined into one block, but have different terminals.
Where can I find the markings for replacing the relay?
The markings are usually placed on the top or side edge of the relay body. Look for abbreviations like RTK, R-600, 117N0011, etc. It is also important to know the power and model of your compressor.