If your refrigerator suddenly stopped cooling food or began to make unusual sounds, buzzing and click, the first thing many people do is look for information about possible causes. Often the culprit of such problems is the capacitor. This small but critical component is responsible for the startup and stable operation of the compressor, which is the “heart” of the entire cooling system.
In this article we will examine in detail what is a capacitor in a refrigeratorwhat functions it performs and why starting the engine is often impossible without it. We will not delve into the complex physics of the processes, but will focus on practical aspects: how to understand that a part has failed, whether it is possible to replace it yourself and what to look for when choosing a new element for your model of equipment.
Understanding the structure of your household appliance is the first step to its long and uninterrupted service. Knowing how it works starting capacitor, you can avoid panic in the event of a sudden breakdown and competently assess the situation, deciding whether it is worth calling a technician or whether you can handle it on your own with a minimum set of tools.
Operation principle and main functions
Capacitor in the refrigerator system is a storage device for electrical energy. When the refrigerator is turned on, the compressor requires a powerful current pulse to move the motor rotor and start the process of compressing the refrigerant. The usual power of the network is often not enough for this, and here the starting capacitor comes into play starting capacitor.
It accumulates charge and releases it at the right moment, creating the necessary phase shift in the windings of the electric motor. This allows the motor to overcome the initial resistance and enter operating mode. After starting, the capacitor is disconnected from the circuit, and further operation is ensured by the working winding of the motor.
In modern models of refrigerators, especially those equipped with inverter compressors, the role of capacitors can be distributed between starting and working elements, or their functions are taken over by a complex electronic control board. However, in classic linear models this component remains indispensable.
⚠️ Attention: Trying to start a refrigerator with a faulty or missing capacitor may lead to burnout of the compressor windings. If you hear a hum, but the engine does not start, immediately unplug the device.
It is important to note that working capacitor (if provided by the design of a particular model) helps maintain a stable voltage while the engine is running, smoothing out surges and increasing the efficiency of the system. This reduces energy consumption and reduces wear of mechanical parts.
Types of capacitors and their location
In domestic refrigerators, mainly two types of these devices are used, and they should not be confused, since they have different technical characteristics and purposes. The first type is starting capacitors, which work only at the moment of start. The second type are workers who are constantly in the chain.
The location of the element depends on the design of the refrigeration unit. In most classic models, it is located in close proximity to the compressor, at the lower rear of the refrigerator. Often the capacitor is fixed directly on the motor housing or next to it in a special plastic box.
In some models, for example, in refrigerators Indesit or Ariston old series, the starting device can be combined with a thermal relay in one unit. In more modern systems, such as U Bosch or Siemens, the components may be separated or integrated into a common control board.
The following is a table to help distinguish the main parameters of typical capacitors used in refrigeration technology:
| Parameter | Starting capacitor | Running capacitor |
|---|---|---|
| Operating time | Short-term (1-3 seconds) | Continuous |
| Capacity (µF) | High (50-400 µF) | Low (2-20 µF) |
| Voltage (V) | Usually 220-450 V | Usually 400-600 V |
| Dielectric material | Often electrolytic | Polypropylene (MKP) |
When looking for a replacement part, it is critical to pay attention to marking. Capacity of the capacitor must match the original, and the operating voltage must be equal to or exceed the rated value of the old part. Using a part with less voltage will lead to its rapid failure.
Symptoms of malfunction and diagnostics
How to understand that the problem lies in the capacitor? There are a number of characteristic symptoms that indicate a faulty starter. The most obvious sign is when the refrigerator hums but does not turn on.
You can hear the characteristic hum of the compressor, which lasts for several seconds, after which the relay clicks and the sound stops. After some time, the cycle repeats. This indicates that the engine is trying to start, is receiving power, but cannot turn the shaft without an additional impulse from the capacitor.
Another sign may be that the refrigerator turns on, but cools very weakly or does not cool at all. If the compressor runs jerkily or quickly heats up and turns off via a thermal relay, this may also indicate problems in the starting circuit.
For more accurate diagnostics, you will need a multimeter. Before checking, be sure to disconnect the refrigerator from the power supply! Remove the capacitor and discharge it by shorting the contacts with an insulated screwdriver (if it is electrolytic and of large capacity). Switch the multimeter to resistance measurement or capacitance testing mode.
If the meter shows infinite resistance or no response, the capacitor is “dead”. If the resistance drops to zero, a breakdown has occurred. A normal capacitor, when checked with an ohmmeter, should show a smooth change in resistance.
⚠️ Attention: Even if there are visually no swelling or traces of burning on the capacitor, this does not guarantee its serviceability. An internal break in the lining is not visible to the eye, so checking with a device is mandatory.
Instructions for replacing a capacitor
Replacing a capacitor is one of the most accessible procedures for a home craftsman, which does not require special education, but requires caution. The process does not take much time if you act consistently and follow safety precautions.
The first thing you need to do is provide access to the compressor. This usually requires moving the refrigerator away from the wall and removing the rear protective panel (crankcase) that covers the engine compartment. In some models, for example, built-in refrigerators Liebherr, access may be limited by the design of the niche.
After removing the panel, you will see the compressor (black metal “barrel”). Next to it, often in a plastic casing or simply secured with a clamp, will be the element we need. Before removing, take a photo of the wire connection diagram so as not to mix up the contacts when installing a new part.
☑️ Preparation for replacement
Remove the old capacitor by disconnecting the terminals. Install the new element in the same position, secure it and connect the wires according to the photo taken earlier. Make sure the connections are tight and not loose. After this, you can conduct a preliminary test.
Plug in the refrigerator. If you hear the compressor start confidently without prolonged buzzing or clicking, it means the replacement was successful. Replace the protective panel and push the refrigerator into place, maintaining the necessary distances from the walls for ventilation.
Why capacitors fail
Capacitors are reliable parts, but not eternal. There are several main reasons why they cease to perform their functions. One of the most common is voltage drop in the electrical network. Voltage surges can break through the dielectric inside the element.
The second important factor is temperature. The compressor gets very hot during operation, and although the capacitors are designed for high temperatures, constant overheating (for example, due to poor ventilation or contamination of the radiator at the back of the refrigerator) accelerates the aging of the electrolyte or polymer film inside.
Natural wear and tear should also be taken into account. Over time, internal chemical processes cause the electrolyte in electrolytic capacitors to dry out, reducing their capacity. The part stops accumulating the required charge, and the compressor stops starting.
In rare cases, the cause of a breakdown may be a manufacturing defect or the use of low-quality materials by the component manufacturer. This is more common in budget models of refrigerators, where they save on every detail.
⚠️ Attention: If after replacing the condenser the refrigerator stops working again after a short time, the problem may not be in the part itself, but in a malfunction of the compressor or relay, which creates a load that destroys the new element.
Selection of spare parts: original or analogue
When purchasing a new condenser, the refrigerator owner is faced with the question: look for an original spare part from the equipment manufacturer or take a universal analogue. Original parts, such as for refrigerators LG or Samsung, guarantee full compliance, but are often more expensive and harder to find for sale.
Universal capacitors from well-known electronics manufacturers (for example, CBB60, CBB61 series) are often an excellent choice. The main thing is to strictly observe the parameters: capacitance (uF) and operating voltage (V). Geometric dimensions are also important so that the part fits in the allotted space.
You should not buy cheap “no-name” capacitors on markets without markings. Their actual capacity may differ greatly from the declared one, and their service life can be calculated in weeks. Saving a couple of dollars can lead to repeated breakdowns and failure of a more expensive compressor.
Is it possible to use a capacitor with a larger capacity?
Using a capacitor with a capacity exceeding the original by more than 10-15% is not recommended. This can lead to overload of the starting winding of the motor and its combustion. It is better to look for an exact match or the smallest possible deviation downward if there is no exact analogue.
When choosing, pay attention to the standard size and method of fastening. Some capacitors have leads in the form of “petals” under the terminals, others in the form of wires. In the second case, a connection via a terminal block or soldering may be required, which requires additional skills.
Prevention and care of the starting system
In order for the capacitor and the entire starting system to serve for a long time, it is necessary to ensure the correct operating conditions of the refrigerator. First of all, this concerns ventilation. The back wall of the refrigerator, where the compressor is located, must have free access to air.
Regularly removing dust from the radiator grilles and the compressor itself helps to avoid overheating. Dust acts as a heat insulator, preventing parts from cooling, which shortens the life of the capacitor and other electronic components.
It is also recommended to use a voltage stabilizer if your network experiences frequent surges. This will protect not only the condenser, but also the entire electronics of the refrigerator, including the control board and compressor motor.
Monitor the condition of the door seals. If the door does not close tightly, the compressor is forced to work longer and turn on more often to maintain the temperature. Increasing the number of starting cycles accelerates the wear of the starting capacitor.
Is it possible to start a refrigerator without a capacitor?
Theoretically, some powerful motors can start without a starting capacitor if you manually turn the shaft, but in domestic refrigerators this cannot be done without disassembling. In addition, operation without a starting element will lead to rapid overheating and burning of the starting winding. You cannot operate a refrigerator without a working condenser.
How much does it cost to replace a capacitor in the service?
The cost consists of the price of the part itself (usually from 300 to 1000 rubles depending on the model) and the work of the technician. At the service center, the full cost of the service can vary from 1,500 to 3,000 rubles. Replacing yourself allows you to save on work, since the procedure is quite simple.
What is the difference between a starting and running capacitor?
The starting capacitor is included in the circuit only for a few seconds at the moment the engine starts, helping it gain speed. The running capacitor is constantly connected to the circuit while the refrigerator is running, improving engine performance and compensating for reactive power. They are not always interchangeable.
Where can I find the capacitor markings?
The marking is applied to the body of the part, usually on the side surface. The main parameters are indicated there: capacitance (for example, 30 µF), voltage (for example, 450V AC), tolerance and temperature conditions. If the marking is erased, it is better to remove the part and select an analogue according to the catalog number or parameters from the technical documentation of the refrigerator.
Is it dangerous to change the capacitor yourself?
Replacement is safe if you follow one main rule: work only with the device disconnected from the network. There may be a residual charge in the capacitor, so it is recommended to discharge it before touching the contacts (short the contacts with a dielectric or an insulated screwdriver). If these measures are followed, the risk is minimal.