Did the refrigerator Beko stop freezing or, conversely, start working without interruption? In most cases, the culprit is the compressor - the heart of the cooling system. Diagnostics this unit requires care, but is quite within the capabilities of a home handyman with basic knowledge of electrical engineering. Do not rush to call a technician or buy a new unit until you are sure that the motor is faulty.
The first sign of problems is often unusual behavior of the equipment: humming without starting, lack of cold, or constant operation of the engine. It is important to distinguish mechanical failure of the compressor itself from failures in start-protective relay or the thermostat. It is these auxiliary elements that fail more often than the motor itself.
In this article we will analyze a step-by-step testing algorithm, the necessary tools and ways to interpret multimeter readings. You will learn how to safely reach the contacts and what resistance values are considered normal for various models Beko. Correct defection will help save a significant amount on repairs.
⚠️ Attention: All work on diagnosing the electrical equipment of the refrigerator should be carried out only with the power completely disconnected from the network. Do not touch live parts under voltage!
Visual inspection and initial assessment of condition
Before picking up a multimeter, conduct a thorough external inspection of the back of the refrigerator. The compressor is usually located in a niche below, protected by a casing. Remove the protective panel by unscrewing the mounting screws to gain access to the unit. Visually assess the condition of engine housing and suitable pipes.
Pay attention to the presence of oil smudges. If traces of oil are visible around the fittings or on the body itself, this is a sure sign of depressurization of the system. In this case, further electrical testing may be pointless because the refrigerator has lost refrigerant. Also inspect the wires for melted insulation or oxidation of contacts.
Plug in the refrigerator and listen. A working motor should start with a characteristic hum a few seconds after the relay clicks. If you only hear a quiet hum, followed by a clicking sound and silence, the engine is trying to start but cannot. This may indicate interturn short circuit or jamming of the mechanism.
If the compressor is completely silent, the problem may be a lack of power at the terminals. Check whether the ground or phase wire has come loose from the contact group. Often the problem lies in a banal contact failure, and not in a burnt winding.
Necessary tools and preparation for work
For For high-quality diagnostics, you will need a minimum set of tools. The main device will be a digital multimeter (tester) capable of measuring resistance in Ohms. Without it, it is impossible to determine the integrity of the windings. You will also need screwdrivers (Phillips and flathead) to remove panels and terminals.
To clean the contacts from oxides or carbon deposits, prepare fine sandpaper or a needle file. Oxidized contacts may give false resistance readings, leading to misdiagnosis. Additionally, electrical tape may be required for marking wires or temporary insulation.
Make sure you have access to a grounded outlet for short-term test connections, if necessary at the final stage. However, the main check is carried out with the unit completely de-energized and disconnected from the network.
☑️ Preparation for diagnostics
Dismantling and access to the contact group
To ring the windings, you need to get to the output contacts of the compressor. They are hidden under a plastic casing that also protects the start relay. Carefully remove the housing clips. In some models Beko the relay is simply put on the pins of the compressor, in others it is attached with a bracket.
After removing the relay, you will see three or four pins coming out of the motor housing. There are usually three of them: two for windings and one for grounding. Some models may have a fourth contact for thermal protection built into the housing. It is important not to confuse their purpose when dialing.
The contact group often has markings, but they can be erased or difficult to read. The standard circuit assumes the presence of a common point, a starting winding output and a working winding output. For accuracy, it is better to find the electrical diagram of your model on the Internet or service documentation.
If black deposits or oxidation are visible on the contacts, carefully clean them. Poor contact between the relay connector and the compressor pin is a common cause of overheating and subsequent breakdown. After cleaning, wipe the surface with alcohol.
How to distinguish a relay from a compressor?
The starting relay is a separate plastic block that is placed on the motor contacts. Inside it there is a starting coil or posistor, as well as a thermal release. The compressor itself is a massive black “tank” at the bottom of the refrigerator.
Checking the integrity of the windings with a multimeter
This is the most important diagnostic stage. Set the multimeter to resistance measurement mode (Ohm, limit 2 kOhm or 20 kOhm). First check the presence short circuit on the case. Touch one probe to any contact of the compressor, and the other to a stripped place on the housing (where there is no paint) or to a copper tube.
If the device shows resistance (numbers), it means that the winding is broken into the housing. It is dangerous to operate such a compressor and requires replacement. If the device shows infinity (one in the most significant digit or OL), the insulation is intact.
Next, we measure the resistance between pairs of contacts. A standard single-phase motor has three terminals. There must be some resistance between them. Between the working and starting windings, the sum of the resistances should give the total resistance between the extreme contacts. Typically, the operating winding has less resistance than the starting winding.
Normal resistance values for compressors Beko vary depending on the power, but usually lie within the following limits:
| Pair of contacts | Normal resistance (Ohm) | What does deviation mean? |
|---|---|---|
| Working winding | 10 - 25 Ohm | Infinity - open, 0 - shorted |
| Start winding | 20 - 40 Ohm | High resistance - burnout |
| General (between extremes) | The sum of the two is higher | Inconsistency of the sum - measurement error |
| Contact - Housing | Infinity (∞) | Any value is an insulation breakdown |
If the values differ greatly from the norm or there is no resistance at all (break), the compressor is faulty. However, if the resistance is normal, this does not yet guarantee 100% serviceability of the mechanical part.
Diagnostics of the starting relay and thermal protection
Often the compressor itself is working, but does not start due to a burnt-out starting relay. This device supplies an impulse to the starting winding. Check the relay visually: there should be no burning inside, and the posistor (if there is one) should not be split.
Ring the relay contacts. In a cold state, the thermal protection contacts should ring (resistance is close to zero). If the circuit is broken, the relay needs to be replaced. There are special testers to check the starting ability of the relay, but at home it is easier to replace it with a known-good similar one.
Thermal protection (thermal relay) is often built into the overall structure or located next to the compressor. Its task is to turn off the motor when it overheats. If it is faulty and is constantly open, the compressor will not receive power. Ring it: there should be a short circuit (0 Ohm) at normal temperature.
Replacing a relay is an inexpensive procedure. Make sure that the new relay is suitable for the current parameters and connection type. A code is usually written on the relay body, for example 14-118 or a similar one, which must be taken into account when selecting.
⚠️ Attention: Do not try to repair the insides of the starting relay (glue, solder). These are disposable elements, and their incorrect operation can lead to burnout of the compressor windings.
Symptoms of interturn short circuit and wedge
There are cases when the multimeter shows ideal winding resistance, but the compressor hums, gets hot and knocks out the circuit breaker or thermal protection. These are signs turn-to-turn short circuit. Some of the turns of the winding close together, changing the characteristics of the motor, but without breaking the circuit completely.
It is difficult to identify an inter-turn short circuit with a conventional tester. An indirect sign is increased current consumption. For accurate diagnostics you need an ammeter (current clamp). When starting, the current should not exceed the rated current indicated on the compressor nameplate (usually 0.5 - 1.2 A for household refrigerators).
If the current is significantly higher than the norm (for example, 3-5 A) and the motor is humming, there is a wedge in the mechanical part or a strong short circuit. In this case, the compressor is jammed and it is impossible to defrost it. Replacement is required.
Another symptom is the rapid heating of the compressor housing to a scorching temperature in the first minutes of operation. A working engine warms up, but gradually. If it heats up in 2-3 minutes and turns off due to thermal protection, this is a bad sign.
FAQ: Frequently asked questions
Is it possible to restore a jammed compressor?
There is a method of “wedging” by applying increased voltage (380V) for a short time, but at home conditions this is extremely dangerous and rarely gives long-term results. For refrigerators Beko it is more reliable and safer to replace the unit.
Why does the compressor hum but does not start?
The main reasons: the starting relay is faulty (does not give a starting impulse), the piston group is jammed, an interturn short circuit or critically low voltage in the network. You should start checking with the relay.
How much does it cost to replace a compressor with Beko?
The cost consists of the price of a new compressor (depending on the model) and the work of the technician. Independent replacement is possible, but requires the skills of soldering copper tubes, evacuation of the system and refilling with freon, which requires special equipment.
Can the thermostat be the reason that the compressor does not turn on?
Yes, if the thermostat is faulty and does not close the circuit when the temperature in the chamber rises, the signal to start the compressor will not be received. Check the thermostat by closing its contacts directly: if the motor starts working, the problem is in the sensor.