Sudden stoppage of compressor operation refrigerator Atlant often takes you by surprise, forcing you to look for the causes of failure in the most complex components of the unit. However, statistics from service centers show that in a significant number of cases the problem lies in the failure of the starting capacitor or start-protection relay, which are responsible for starting the engine. Replacing the capacitor is one of the few procedures that the owner of the equipment can perform independently, without having in-depth knowledge of electrical engineering, but requiring strict adherence to safety measures.
The correct connection of this element is critically important, since it is it that provides the necessary phase shift to start the asynchronous compressor motor. If this process is disrupted, the motor will either not start at all or will work with overload, which will inevitably lead to its combustion. In this article, we will analyze in detail how to diagnose a malfunction, select the correct analogue and correctly connect it in refrigerators of the Belarusian brand. Atlant.
Before starting any work, you must completely disconnect the device from the power supply by unplugging the plug from the socket, and provide access to the motor-compressor located in the lower rear part of the case. Electrical diagram refrigerators Atlant is quite simple and unified for most models, be it double-chamber series or single-chamber versions, which greatly simplifies the diagnostic process. Your task is not just to replace the part, but also to understand the reason why the previous one failed in order to avoid a repetition of the situation in the near future.
Design of the starting system of the Atlant refrigerator
Single-phase starting system The compressor installed in household refrigerators consists of two main components: a start relay and a capacitor (in some circuits). In modern models Atlant most often a circuit with a starting winding is used, where the capacitor can be integrated into the relay unit or connected separately depending on the type of engine. Start relay is responsible for briefly connecting the starting winding at the time of start, and then turns it off when the rotor reaches the required speed.
The capacitor in this circuit performs the function of creating the phase shift necessary for the occurrence of torque. Without this element, the magnetic field in the stator would be pulsating rather than rotating, and the motor would remain motionless, only humming from the passing current. In older models, large capacitors could be used, while in new circuits their role is often taken on by electronics or a specific relay design, however, the classic circuit with a capacitor remains common.
⚠️ Attention: In some models of refrigerators Atlant the starting capacitor is structurally combined with the starting relay housing. In such cases, the entire unit must be replaced, since opening the sealed relay case to replace the capacitor is technically impractical and unsafe.
It is important to distinguish between starting and operating capacitors, since they have different characteristics and purposes. The starting ones operate for a short time and must have a high capacity, while the working ones are constantly in the circuit. Wrong selection the type of capacitor will either lead to the impossibility of starting, or to overheating of the windings and eventual combustion of the compressor. The documentation for a specific model always indicates the required capacitance and operating voltage.
What is the difference between the starting and operating relays?
The starting relay opens the starting winding circuit after the engine starts (usually after 1-3 seconds), using a thermal or electromagnetic principle. The operating relay (less commonly found in domestic refrigerators as a separate unit) controls the operation of the engine in normal mode. In the context of replacing a capacitor, we are interested in the starting circuit, where the maximum current load occurs at the moment of start.
Diagnostics of a capacitor malfunction
Before buying a new part, you need to make sure that the problem lies in the capacitor, and not in the compressor itself or the wiring. The primary sign of a faulty starting system is a characteristic clicking sound from the relay, followed by a hum from the compressor, but the engine itself does not start. After a few seconds, the thermal protection is triggered, a second click is heard, and the cycle is repeated after a certain period of time.
Visual inspection often reveals obvious signs of breakdown: swelling of the capacitor body, traces of burning, melting of the terminals or leakage of electrolyte. If the capacitor body is deformed or has cracks, its operation is strictly prohibited, as this may lead to a short circuit. However, the absence of external defects does not guarantee serviceability, so an instrumental test is necessary.
For accurate diagnostics, you will need a multimeter capable of measuring the capacitance of capacitors. Before measuring, be sure to discharge the capacitor by shorting its contacts with an insulated screwdriver to avoid electric shock and damage to the device. Switch the multimeter to the capacitance measurement mode and connect the probes to the contacts: the readings must correspond to the rating indicated on the case (usually from 2 to 10 µF for household refrigerators).
It is also worth checking the condition of the contacts on the relay itself and the wires going to the capacitor. Oxidation or burning of contacts creates additional resistance, which prevents normal engine starting even with a working capacitor. Cleaning the contacts with fine sandpaper or replacing the terminals can solve the problem without replacing expensive components.
Selecting a suitable capacitor for replacement
Selecting an analogue for replacement is a critical stage on which the longevity of the refrigerator depends. Atlant. The main selection parameters are capacitance (measured in microfarads, μF) and operating voltage (Volts). The container must exactly match the compressor manufacturer's requirements; the permissible deviation is usually no more than ±5-10% of the nominal value.
The operating voltage of the capacitor must be no less than the mains voltage, taking into account possible surges. For refrigerators operating from a 220V network, it is recommended to choose capacitors with a voltage of at least 250V, and preferably 300-400V. Installing an element with a lower voltage will lead to its rapid failure and possible explosion of the housing due to breakdown of the dielectric.
Overall dimensions also matter, since the capacitor must physically fit into the designated space on the compressor casing or in the relay block. If the original element had a specific shape, you can use a universal cylindrical capacitor, securing it with clamps or hot glue, the main thing is to ensure a reliable electrical connection.
Below is a table of parameter correspondence for models of compressors installed in refrigerators Atlant:
| Model compressor | Capacitor type | Capacity (uF) | Operating voltage (V) |
|---|---|---|---|
| SKN 100 (R600a) | Starting | 4.0 - 5.0 | 250 - 300 |
| SKN 140 (R134a) | Starting | 6.0 - 8.0 | 250 - 350 |
| NMK 10 (R134a) | Starting | 5.0 - 6.0 | 300 |
| Universal analogue | Starting | By marking | Minimum 250 |
Step-by-step instructions for connecting
The replacement process begins with dismantling the plastic casing covering the compressor. It is usually secured with latches or bolts that must be carefully unscrewed. After removing the protection, you will see the compressor itself, to the side of which there is a black plastic box attached - this is the starting relay with a capacitor.
Remove the relay from the compressor contacts. It can be held on by spring clips or simply sit tightly on three contact pins. Gently rocking from side to side (without jerking), remove the knot. Disconnect the wires going from the capacitor to the relay and terminals, having first memorized or photographed the connection diagram. Color marking The wires may differ in different modifications, so the photo will be the best guide.
☑️ Checklist before connecting
Install a new capacitor in place of the old one. If the terminals of the new element do not match the type of wires of the refrigerator, use adapter terminals or carefully solder the wires, observing the polarity (if it is indicated, although this is not critical for non-polarized capacitors). The main thing is to ensure tight contact to prevent sparking.
Connect the assembled structure to the compressor contacts. Make sure the relay sits snug and upright (or as originally installed) as some relay types are position sensitive. Put on the protective cover, plug in the refrigerator and listen: the startup should be quiet, without prolonged buzzing or clicking.
⚠️ Attention: Technical characteristics of compressors and connection diagrams may vary slightly depending on the year of manufacture of the refrigerator. Atlant. Always check the markings on the compressor nameplate with the data in the technical documentation before purchasing spare parts.
Typical installation errors
One of the most common mistakes is ignoring the condition of the wires. Even when installing a new capacitor, old, dry or broken wires can cause system failure. The insulation on the wires leading to the compressor often cracks due to high temperatures, which can lead to a short circuit to the housing.
Another mistake is using a capacitor with the wrong capacity. Installing an element with a larger capacitance will create an increased starting current, which is dangerous for the motor windings. A smaller capacity will not create sufficient torque, and the compressor will “hum” but will not start, which also leads to overheating.
Poor contact at the joints is the third common defect. Poorly clamped terminals or “twists” without soldering oxidize over time, the resistance increases, the contact heats up and eventually burns out. Use only factory terminals or high-quality soldering followed by heat shrink insulation.
Checking operation after replacement
After successfully replacing the capacitor and assembling the housing, it is necessary to carry out a test run. Plug in the refrigerator and pay attention to the sound of the compressor running. It should start with a characteristic even hum, without extraneous knocking, vibration or intermittent humming.
Check the heating of the compressor housing and the new condenser after 15-20 minutes of operation. A slight warming is acceptable, but if the elements heat up to a temperature at which it is impossible to hold your hand, this indicates a malfunction in the circuit or an incorrect selection of the capacitor. It is also worth checking the operating cycle: the refrigerator should gain temperature and turn off.
If after replacing the capacitor the situation has not changed (the compressor hums and clicks), the problem may lie in the starting relay itself (mechanical part) or, worse, in the interturn short circuit of the compressor windings. In this case, self-repair can be completed, and you will need to call a technician for a more in-depth diagnosis.
What to do if the refrigerator does not freeze after replacement?
If the compressor works, but there is no cold, the problem is not in the electrics, but in the refrigerant or circulation system. There may be a freon leak or a clogged capillary tube. In this case, the capacitor was replaced correctly (since the motor is working), but the system needs to be filled with refrigerant by a specialist.
Frequently asked questions (FAQ)
Is it possible to use a capacitor with a larger capacity if there is no exactly the same one?
Using a capacitor with a capacity exceeding the nominal value by more than by 10-15%, not recommended. This will lead to an increase in starting current, overloading the compressor windings and reducing its service life. It is better to find an exact analog or connect two capacitors of smaller capacity in parallel to obtain the desired rating.
Why does a new capacitor burn out after a short time?
A common reason is power surges in the network or a malfunction of the starting relay itself, which “sticks” and does not turn off the starting winding. It is also possible that the operating voltage of the installed capacitor is lower than that required for your network conditions.
Is it necessary to discharge the capacitor before replacing?
Yes, definitely. Even after being disconnected from the mains, the capacitor can retain its charge. Before touching the contacts, short them with an insulated screwdriver or a resistor to avoid an unpleasant electric shock.
What is the difference between the capacitors for R134a and R600a?
The difference is not in the type of refrigerant, but in the power and characteristics of the specific compressor that uses that refrigerant. Compressors for R600a are often less powerful and may require capacitors of smaller capacity, but you need to focus strictly on the engine marking, and not on the type of gas.