Checking the Atlant refrigerator compressor with your own hands

The situation when a two-chamber refrigerator Atlant stops cooling, and only a quiet hum is heard inside or, conversely, there is deathly silence, always takes you by surprise. In most cases, the cause of the breakdown is the failure of the motor-compressor, which is the heart of the entire refrigeration system. Before calling a technician or buying new equipment, it makes sense to carry out an initial diagnosis of the unit yourself in order to understand the scale of the problem and the cost of a possible restoration.

This procedure requires a minimum set of tools and basic knowledge in the field of electrical engineering, but at the same time allows you to accurately determine the condition of the electrical part of the engine. Important to understandthat checking the compressor is just the first stage, which eliminates electrical faults, but does not always guarantee the serviceability of the mechanical part or the refrigerant circulation system. If you are ready to approach the matter carefully and follow safety precautions, you can save a significant amount on diagnostics.

In this article we will analyze in detail the algorithm of actions for checking compressors installed in popular models Atlant MHM 1700, 1800, 2808 and other series. We will look at methods for testing the windings, checking for insulation breakdown and assessing the state of the starting relay, which will give you a complete picture of the performance of the unit.

Safety precautions and workplace preparation

Any work related to electrical appliances and their internal components carry a potential shock hazard. The refrigerator Atlant is connected to a household network with a voltage of 220 volts, which is deadly for humans. Therefore, the very first and unshakable rule is to completely disconnect the device from the power supply before starting any manipulations.

⚠️ Attention: Never diagnose the compressor while the power cord is plugged into the outlet. Even if the refrigerator is turned off with a button, dangerous potential may remain on the contacts. Unplug the plug from the socket before removing the back cover.

In addition to electrical safety, you should also take care of the physical safety of the components. The compressor in two-chamber models often heats up to high temperatures during operation. If the unit has just been operating, allow it to cool for 30-40 minutes to avoid burning your hands or damaging the plastic elements when touched. Also ensure good lighting of the work area, since the rear niche of the refrigerator is usually darkened.

To carry out high-quality diagnostics, you will need to prepare the following tools:

• 🔧 Multimeter (tester) - the main device for measuring resistance and checking the integrity of circuits.
• 🪛 Screwdrivers (phillips and flat) - for dismantling the protective cover of the compressor compartment.
• 🧤 Dielectric gloves - for additional protection when working with contacts.
• 🔦 Flashlight - for illuminating hard-to-reach places in the niche of the unit.

Make sure the floor is under the refrigerator is dry and clean. While working, you may have to bend over or lie down on the floor, so lay down cardboard or thick fabric. This will protect not only you, but also the floor covering from possible scratches with tools.

Access to the compressor and visual inspection

In two-chamber refrigerators Atlant the compressor unit is traditionally located in the lower rear part of the case. To access it, you need to remove the metal or plastic cover covering the engine compartment. Usually it is secured with four bolts or self-tapping screws around the perimeter, but some older models may use latches.

After dismantling the cover, you will have a view of the main components: the compressor itself (black metal cylinder), the capacitor (coil) and the start-up relay. Primary visual inspection can provide important information about the state of technology. Carefully examine the surface of the motor for traces of oil, soot or deformation. The presence of oily smudges at the bottom of the compartment often indicates depressurization of the system, which requires complex repairs including replacing the filter and refilling with freon.

Pay special attention to the condition of the wires and contacts. The insulation must not be melted, cracked or blackened. If you see burn marks on the plastic housing of the start relay or on the terminal block, this is a sure sign of overheating and a possible short circuit. In such cases, a simple test may no longer be informative, since the circuit could have completely burned out.

If there is no external damage, you can proceed to a more in-depth diagnosis. Disconnect the start relay from the compressor. It can be removed by simply shaking it down and to the side, after which the block with wires is removed from the motor contacts. Now you have direct access to the three contacts of the motor windings, which is necessary for further measurements.

Diagnostics of the windings with a multimeter

The most reliable way to check the electrical health of the motor is to measure the resistance of its windings. To do this, switch the multimeter to resistance measurement mode (Ohms), selecting a limit of 200 Ohms or 2 kOhms. On the contacts of the compressor Atlant usually there are three terminals that form a triangle: two upper and one lower (or located in a different configuration depending on the model).

The measurement process involves ringing the contacts in pairs. You need to measure the resistance between each pair of pins. In a working single-phase motor, you should get three values ​​that will correspond to the sum of the resistances of the starting and operating windings. Normal indicators for different models Atlant may vary, but the general logic remains the same: the resistance between any two contacts should not be zero or infinite.

Let's consider possible scenarios for the device readings:

• 📉 Infinity (one on the screen) —indicates a winding break. The motor has burned out and requires replacement, since rewinding at home is impossible and economically unfeasible.
• 📉 Zero or close to zero value —indicates an interturn short circuit. This is also a fatal malfunction in which the motor will hum, knock out the machines and not start.
• 📉 Stable resistance - if the device shows specific numbers (for example, 20-40 Ohms), this is a good sign indicating the integrity of the turns.

It is worth noting that the exact resistance values depend on the power of the motor and its model. For example, for compressors Atlant series CT or N the resistance of the working winding is usually 10-15 Ohms, and the starting winding is 20-35 Ohms. The total resistance between the extreme contacts will be equal to the sum of these values. If your measurements differ radically from the expected ones, it is worth rechecking the calibration of the device.

Checking for insulation breakdown (housing)

Even if the windings are intact, there is a risk of insulation breakdown on the housing. This is a situation when a phase shorts to the metal cylinder of the compressor. Such a malfunction is extremely dangerous: the refrigerator can work, but its body will receive an electric current, which creates a direct threat to people’s lives, especially in conditions of high humidity (kitchen, floor).

To check for breakdown, switch the multimeter to the dialing mode (where there is a sound signal) or measuring resistance to the maximum limit (20 MOhm). With one probe, touch the cleaned area on the metal body of the compressor (you can use the relay mounting location or a specially cleaned area of ​​paint), and with the other, touch each of the three motor contacts in turn.

⚠️ Attention: In good condition, the device should show infinity (or no sound signal). If the multimeter beeps or shows any resistance, then the insulation is broken. Operating such a refrigerator is strictly prohibited without replacing the unit.

Sometimes the breakdown can be “floating”. This means that on a cold engine the insulation holds, but when heated to operating temperature (60-80 degrees) it is broken. If there is no breakdown during cold continuity, but the refrigerator knocks out the RCD or circuit breakers some time after switching on, suspect a thermal breakdown of the insulation. In this case, the compressor must also be replaced.

The table below shows typical diagnostic results and their interpretation for refrigerators Atlant:

Analysis of the starting relay and thermostat

It often happens that the compressor itself Atlant is fully operational, but the refrigerator does not start due to malfunctions in the control circuit. The key element here is the start relay, which supplies an impulse to the start winding. In two-chamber models, relays of type RT, P-3 or their modern analogues are most often used.

Checking the relay begins with a visual inspection. Shake it next to your ear: if you hear the ringing of broken internals or knocking, it means that the coil or core has collapsed inside. Also inspect the contacts for carbon deposits. If the relay is working properly, but the motor hums and clicks without starting, the piston group may be jammed, but most often the relay or low voltage in the network is to blame.

It is also worth mentioning the thermostat and defrost sensors, which open the compressor power circuit. If the sensor is “stuck” in the open state, the motor simply will not receive a command to start. However, if you directly supply 220V to the contacts of the compressor (bypassing all the automation) through a working relay, and it starts, then the problem is in the control circuit, and not in the motor.

For those who decided to connect directly to check:

• 🔌 Prepare a wire with a plug and two clamps.
• 🔌 Connect one wire to the common terminal of the compressor.
• 🔌 Briefly short-circuit the second wire to the starting and working terminals at the same time (only for a split second!).
• 🔌 If the motor hums and jerks, but does not start, it is possible that jamming.

Mechanical faults and jamming

Electrical serviceability of the windings is only half the story. A compressor Atlant is a complex mechanical unit where pistons compress gas. Over time, the oil thickens, parts wear out, and so-called “seizing” can occur. In this case, the motor hums, the current consumption increases to the maximum, the thermal protection is triggered, but the shaft does not rotate.

It is more difficult to diagnose jamming. If, when voltage is applied (via the stock relay), a loud hum is heard that lasts 3-5 seconds, followed by a shutdown click and silence, this is a classic symptom. The thermal relay saves the windings from burning out by opening the circuit. Repeated attempts to turn on at short intervals can finally finish off the engine.

There is a “wedging” method by applying increased voltage or a pulse, but at home for two-chamber refrigerators Atlant it is rarely effective and safe. Mechanical knocking inside the cylinder, clanging and vibration also indicate destruction of the motor suspension or valve group. In such cases the only solution is a complete replacement of the compressor unit followed by evacuation and charging of the system.

Frequently asked questions (FAQ)

Is it possible to repair the Atlant refrigerator compressor with your own hands?

No, modern compressors are sealed units (soldered). Disassembling them at home is impossible without special equipment and loss of tightness. If internal defects (windings, mechanics) are detected, the unit must only be replaced.

Why may a new compressor not start after replacement?

There may be several reasons: incorrect installation of the start relay, lack of freon charging (in some systems there is a pressure sensor), a malfunction in the control circuit, or a defect in the new unit itself. It is also important to check whether the discharge tube is rolled during installation.

How much does it cost to replace a compressor in a two-chamber Atlanta?

The cost consists of the price of a new unit (which varies depending on the model and manufacturer) and the cost of the work of a specialist for vacuuming and refilling. Exact prices depend on the region and service, so it is better to check the latest information at official service centers.

Is it dangerous to leave a refrigerator with a broken compressor?

Yes, it is deadly. If the insulation breaks down, the entire metal body of the refrigerator becomes energized. Touching it on a wet kitchen floor can be fatal. Such a device must be immediately disconnected from the network.

How to distinguish a compressor malfunction from a freon leak?

If the compressor starts, runs constantly (does not turn off), but there is no cold, and the tubes on the rear grille are cold or warm (and not hot/cold cyclically) - most likely there is a freon leak. If the motor does not start at all or immediately turns off with a click, the problem is in the electrics or mechanics of the motor.