Searching for refrigerator compressor windings: from theory to practice

When the refrigerator stops freezing or makes suspicious noises sounds, the culprit is often the compressor - the “heart” of the system. But before changing it entirely, it is worth checking the condition of the windings. These copper coils inside the housing can burn out, short out, or lose insulation, causing malfunction. Finding them yourself is not an easy task: the compressor is sealed, and access to the insides requires caution and knowledge of the design.

In this article we will look at how to safely get to the windings, what tools are needed for diagnostics, and what to do if you find a malfunction. You will learn how to distinguish the starting winding from the working winding, what resistances are considered normal for different models, and why check with a multimeter is only the first step in diagnosis. We will also warn against typical mistakes that can turn repairs into expensive breakdowns.

Why compressor windings fail: the main reasons

Compressor windings are coils of copper wire coated with insulating varnish. They operate under conditions of constant temperature changes, vibrations and high voltage. Even minor defects can lead to serious problems. Here are the most common reasons for their damage:

• 🔥 Overheating. The compressor overheats due to a faulty fan, a dirty condenser or prolonged operation without shutting down. A higher temperature 120°C destroys the insulation of the windings.
• ⚡ Power surges. Sudden changes in the electrical network (especially in rural areas) pierce the insulation, causing interturn short circuits.
• 💧 Moisture and corrosion. If the seal of the case is broken, moisture oxidizes the contacts and wires, increasing resistance.
• ⏳ Natural wear. Over time, the varnish on the windings cracks and the copper oxidizes. On average, the service life of the windings is 10–15 years with proper operation.

Interestingly, in inverter compressors (for example, in LG or Samsung) windings suffer less often due to smooth power control. But in older models (Atlant, Biryusa) with linear compressors, the risk of burnout is higher due to constant starting currents.

⚠️ Attention: If the refrigerator turns off 1-2 seconds after start, this may indicate a problem in the windings. In this case, the compressor requires replacement - repairing the windings at home is almost impossible. interturn short circuit in the windings. In this case, the compressor requires replacement - repairing the windings at home is almost impossible.

Tools and equipment for work

To get to the windings and check them, you will need a minimum set of tools. Some of them can be found in every home, others will have to be purchased or borrowed. Here is the complete list:

For accurate diagnostics it is better to use digital multimeter with a diode testing function - it will help identify breakdowns in the case. Analog testers (with an arrow) are less accurate and can give an error of up to 10%.

If you plan to check the windings inverter compressoryou will need an additional one oscilloscope —without it it is impossible to evaluate the signal shape at the control pins. However, for most household refrigerators (Indesit, Bosch, Atlant), a multimeter is sufficient.

Preparation of the refrigerator: safety first

Before climbing inside the compressor, the refrigerator must be properly prepared. This will not only protect you from electric shock, but will also prevent damage to other components. Follow this algorithm:

Unplug the refrigerator from the outlet and remove the plug|

Wait for complete defrosting (at least 6 hours)|

Move the refrigerator away from the wall to access the compressor|

Take a photo of the location of the wires and terminals before disconnecting|

Place cardboard or a rubber mat under the compressor (vibration can damage the floor) -->

Pay special attention discharging capacitors. Even after being disconnected from the network, they can store dangerous voltage (up to 300 V). To discharge a capacitor, short its terminals with an insulated screwdriver - but do this carefully so as not to damage the part.

If your refrigerator is equipped electronic control unit (as in models Samsung No Frost), before work, disconnect all connectors from it. These boards are sensitive to static electricity, and an accidental discharge can damage them.

⚠️ Attention: Never check the compressor windings without disconnecting it from the refrigeration circuit. Refrigerant under pressure (5–10 atm) can tear out the tubes at the slightest damage, and its inhalation is dangerous to health.

Where the windings are located: disassembly compressor

The windings are hidden inside the sealed compressor housing, and they can only be reached through terminal block a plastic or metal box with three terminals. In most refrigerators (Atlant, Stinol, Indesit) it is located on the top or side of the compressor and is closed with a protective cover.

To get access:

1. Remove the compressor protective casing (usually it is attached to 2-4 self-tapping screws).
2. Clean the terminal block from dust and dirt (you can use a brush or compressed air).
3. Disconnect the wires leading to the block. Remember or take a photo of their location!
4. Unscrew the block mounting bolts (usually there are 2-3 of them) and carefully remove it.

Under the block you will see three winding terminals:

• Common (C) — connected to both windings.
• Working (R) —the main winding, works constantly.
• Starting (S) —turns on only when the compressor starts.

How to distinguish pins if there are no markings?

If there are no letter markings on the terminal block, you can identify the pins by resistance:

- Between C and R: the least resistance (usually 10–30 Ohm).

- Between C and S: average resistance (usually 20–40 Ohm).

- Between R and S: the sum of the two previous values (if the windings are healthy).

If the resistance between any terminals is equal 0 Ohm is a short circuit, if ∞ is an open circuit.

In some models (for example, Danfoss or Embraco) the terminal block may be filled with compound. In this case, you will have to carefully drill holes above the terminals or use special probes to pierce the insulation.

Checking windings with a multimeter: step-by-step algorithm

Now that you have reached the terminals, you can begin diagnostics. Your task is to check three parameters:

1. The resistance of each winding.
2. The absence of a short circuit to the case.
3. The integrity of the insulation between the windings.

Take a multimeter and follow these steps:

1. Set the resistance measurement mode (200 Ohm).
2. Measure the resistance between the terminals:
   • C–R (working winding).
   • C–S (start winding).
   • R–S (total resistance).

Check that there is no breakdown on the case: one multimeter probe to any terminal, the second to the metal body of the compressor. The resistance should be ∞ (infinity).

Normal resistance values depend on the model. compressor. Here are the approximate data for popular brands:

Critical deviation: if the resistance between terminals R and S is not equal to the sum of the resistances C–R and C–S, this indicates an insulation breakdown between the windings. Such a compressor must be replaced.

Typical diagnostic errors and how to avoid them.

Even experienced technicians sometimes make mistakes when checking windings. Here are the most common ones and ways to prevent them:

• 🔌 Checking under voltage. Never measure resistance without disconnecting the compressor from the network. This is not only dangerous, but also distorts the multimeter readings.
• 📏 Incorrect measurement range. If you set the range 2 MΩ instead of 200 Ohmon the multimeter, the device will show 0 even with good windings.
• 🔄 Confusion with. terminals. By mixing up working and starting the results can be misinterpreted. Always label the wires before disconnecting.
• 💦 Ignoring the capacitor. If you do not discharge the capacitor, it can damage the multimeter during measurements.

Another common mistake — sound diagnostics. Many believe that if the compressor hums but does not start, the windings are to blame. In fact, it may be a malfunction starting relay or capacitorCheck them before disassembling the compressor.

⚠️ Attention: If after checking the windings you find that their resistance is normal, but the compressor does not work, the problem may lie in electronic control unit (for models with No Frost) or in thermostat (for simple refrigerators).

What to do if the windings are faulty: repair or replacement?

Unfortunately, rewinding the compressor windings at home, this requires special equipment, vacuum impregnation and precise balancing of the rotor. In 99% of cases, faulty windings mean one thing: the compressor needs to be replaced.

However, there are several. nuances:

• 🔧 If only the starting winding is burned out, some workshops offer to disable it by reflashing the control unit (relevant for inverter models).
• ♻️ For old refrigerators (ZIL, Minsk, you can find used compressors at disassembly sites. The main thing is the match in power and type of refrigerant.
• 💰 Cost of a new compressor is 50–70% from the price of the refrigerator. If your equipment is older than 10 years, it is more advisable to buy a new unit.

When replacing a compressor, be sure to:

1. Use similar model with the same type of refrigerant (R134a, R600a).
2. Replace filter drier and vacuum the system before refueling.
3. Check start relay - it should correspond to the current of the new one compressor.

FAQ: Frequently asked questions about windings. compressor

Is it possible to check the windings without removing the compressor?

Yes, but only the resistance. To do this, disconnect the wires from the terminal block and connect the multimeter directly to the terminals. However, checking for breakdown of the housing requires dismantling the compressor, since the housing is usually grounded through the frame of the refrigerator.

What winding resistance should the compressor have? data-i="261">12–18 Ohm Atlant?

For most models Atlant (with compressors Secop) normal values:

• C–R: 12–18 Ohm
• C–S: 20–30 Ohm
• R–S: 32–48 Ohm

A deviation of more than 20% indicates a malfunction.

What will happen if you turn on a compressor with faulty windings?

The consequences depend on the type of fault:

• Winding break — the compressor will not start, but other components will not be affected.
• Interturn short circuit —the compressor will heat up until will burn out completely or will not knock out the machine in the panel.
• Breakdown to the body is a dangerous situation: it can give an electric shock when touching the refrigerator or cause a fire.

How to check the windings of an inverter compressor?

Inverter compressors (LG Linear Compressor, Samsung Digital Inverter) are checked differently:

1. Measure the resistance between the terminals U, V, W (should be the same, usually 2–10 Ohm).
2. Check that there is no breakdown in the case (as in conventional compressors).
3. Use an oscilloscope, make sure that there are control signals on the inverter board.

Without an oscilloscope, accurate diagnosis is impossible.

Is it possible to repair the windings with your own hands?

Theoretically, yes, but in practice this is impractical. For rewinding you need:

• A special machine for winding.
• Copper wire of the same section and brand.
• Vacuum impregnation with varnish.
• Balancing the rotor.

The cost of work will exceed the price of a new compressor, and the result does not guarantee durability.