A sudden stop in the operation of the refrigerator or, conversely, its continuous hum is always a signal that the cooling system requires urgent intervention. In the line Stinol, as in any other equipment, the core of the unit is the compressor, and it is with its diagnosis that the troubleshooting most often begins. If you notice that it is warm inside the chamber, and the motor is silent or makes strange clicks, you should not immediately call a technician, because the initial check can be performed independently, with a minimal set of tools.
Timely identification of problems with the engine allows you to avoid more expensive repairs, such as replacing the entire refrigeration unit or refilling with freon. Compressor responsible for circulation refrigerant, and if it fails, food can go bad in a matter of hours. In this article, we will analyze in detail the algorithm of actions that will help you understand whether the motor of your Stinola is alive or it already needs replacement.
Before taking active steps, you need to make sure that the work is safe. Any manipulation with electrical equipment requires disconnecting the device from the network, which is the golden rule of any repairman. Ignoring this point can lead not only to electric shock, but also to permanent failure of the control electronics.
⚠️ Attention: Before starting any diagnostic work, be sure to disconnect the refrigerator from the power supply and allow the capacitors to discharge for 5-10 minutes.
Primary visual and auditory diagnostics
The first stage is always an external inspection and analysis of the sound of the unit. Often the nature of the noise or its absence can with a high degree of probability indicate the type of malfunction even before opening the technical compartment. Go to a refrigerator that is working (or trying to work) and listen: does it make a steady hum, an intermittent hum, or can you hear only single clicks of the relay.
If the motor hums, but does not start, or starts and immediately stalls, this may indicate a jammed mechanism or problems with the starting winding. In a situation where compressor it is absolutely silent, but clicks are heard, most likely the thermal protection relay is triggered or the starting device is faulty. It is also worth paying attention to the temperature of the housing: if the motor is hot but there is no cold, this is a bad sign.
Visually inspect the rear wall of the unit. On models Stinol of various years of manufacture, you can often notice traces of oil or soot in the engine area. The presence of oily stains may indicate a violation of the tightness of the compressor housing, which makes its further operation impossible. However, the absence of visible damage does not guarantee the serviceability of the internal mechanics.
Checking the starting relay and electrical circuit
Before sinning on the motor itself, it is necessary to rule out a malfunction of the starting relay, since it is this unit that often becomes the cause of startup failure. The relay is located directly on the compressor housing and is responsible for supplying voltage to the starting winding at the moment of start. To check it, you need to carefully remove it from the contacts and shake it: if a ringing is heard inside, it means that the mechanical part or contacts are broken.
Next, you should ring the electrical circuit with a multimeter. Switch the device to resistance measurement mode (Ohm) and check the contacts on the relay and the wires suitable for them. Lack of continuity where it should be or a short circuit will indicate the need to replace the relay. This is an inexpensive part, and replacing it often solves the problem of a “silent” refrigerator.
It is also important to check the integrity of the windings of the motor itself through the terminal block. There are usually three contacts on the block: two working and one common. The resistance between them must be within certain limits, as will be discussed below. If the multimeter shows infinity (open) or zero (short), then electric motor it has burned out and requires replacement.
☑️ Electrical check
Measuring the resistance of the windings with a multimeter
The most accurate method of diagnosing the electrical part of the compressor is measuring the resistance of the windings. To do this, you will need a multimeter and access to the motor contact group. After removing the start relay, you will see three terminals that are usually labeled or color coded: common (C), start (S), and run (R). In different models Stinol the location may differ, so it is better to check the technical documentation.
The measurement process involves ringing the contacts in pairs. First measure the resistance between the common and working contacts, then between the common and starting contacts, and finally between the working and starting contacts. The obtained values must fit within certain standards. If the resistance between any contacts shows one (infinity), then the winding is broken.
A critically important parameter is checking for insulation breakdown. To do this, apply one multimeter probe to any contact, and the second to the copper tube or compressor housing (pre-clean a small area of paint for better contact). The device should show infinity. Any resistance value indicates that insulation is broken and the motor “breaks through” the housing, which is life-threatening.
| Pair of contacts | Normal resistance (Ohm) | Fault |
|---|---|---|
| General - Working | 10 - 25 Ohm | Open or short circuit |
| General - Starting | 20 - 40 Ohm | Open or short circuit |
| Working - Starting | The sum of the two is higher | Incorrect data |
| Contact - Housing | Infinity (∞) | Insulation breakdown |
Why does the resistance of the windings differ?
The starting winding always has a higher resistance, since it is made of thinner wire and is intended only for a short-term creation of a magnetic field to start the rotor. The working winding is wound with a thicker wire for long-term operation under load.
Analysis of mechanical faults and jamming
If the electrical parameters are normal, but the motor hums and does not start, there is a high probability of mechanical jamming. The piston group inside the sealed housing may have worn out or become stuck due to thickened oil or lack of lubrication. In such cases, the motor shaft cannot make the first turn, and the thermal relay emergency cuts off the power to prevent the windings from burning out.
There is a “wedging” method that sometimes helps to bring the old compressor back to life, although it does not guarantee success. The essence of the method is to apply voltage directly to the starting winding, bypassing the standard relay, which creates a powerful impulse to break the rotor from its place. However, this method is dangerous and requires special skills, since you can get an electric shock or completely finish off the unit.
Signs of mechanical failure are also:
- 🔨 Strong vibration of the housing when trying to start, turning into a dull knock.
- 🌡️ Fast and uneven heating of the motor housing in the lower part.
- 🛑 Absence of the characteristic sound of freon suction in the tubes, even if the motor is humming.
It is worth noting that modern compressors installed in new models Stinolare often maintenance-free. They use technologies that minimize friction, but if the mechanics fail, they can only be completely replaced. Attempting to repair such components is not economically feasible.
⚠️ Attention: Do not try to open the sealed compressor housing yourself. Inside there is oil and freon under pressure, and without special equipment and vacuuming it is impossible to put it back together.
Checking the pressure and integrity of the refrigeration circuit
Even an electrically and mechanically serviceable compressor will not create cold if the tightness of the system is broken. To check the pressure, you will need a pressure gauge station, which is connected to the process fitting (usually a sealed tube with a tapered end). When the compressor is running, the discharge pressure should rise, and the suction pressure should fall, creating a vacuum.
If the compressor pumps, but the pressure does not increase, this may indicate a loss of valve group performance. The piston rings may have worn out and gas is simply being bypassed inside the cylinder head without circulating through the system. In this case, the motor runs easily, without load, but there is no cold. This condition is often confused with a freon leak.
To eliminate leaks, all connections are checked with a soap solution or a special leak detector. Bubbles will indicate the location of depressurization. If there are no leaks and no pressure, then the problem lies in a clogged capillary tube or filter-drier, which creates resistance to the freon flow.
When a compressor replacement is necessary
Replacement compressor is a complex procedure that requires welding equipment for copper pipes, a vacuum pump and refrigerant charging skills. If the diagnostics showed a break in the windings, a breakdown in the housing or mechanical wear of the piston group, then replacement is the only way out. It is almost impossible to do this work independently without experience and tools.
When selecting a new unit for Stinol it is important to consider not only the installation dimensions, but also the power, type of refrigerant (R600a or R134a) and type of oil. Using an unsuitable compressor will lead to rapid failure of the entire refrigeration system. Often, experts recommend replacing the compressor with an analogue with a slightly higher performance if the original is out of production.
The replacement process includes:
- 🛠️ Dismantling the old compressor and removing residual oil from the system.
- 🔥 Soldering new tubes and installation filter-drier.
- 💨 Vacuuming the circuit to remove moisture and air.
- ❄️ Refilling with the exact amount of freon by scale.
Is it possible to replace the Stinol compressor with an analogue from another brand?
Yes, you can often install a universal compressor or an analogue from Danfoss, Embraco or Secop. The main thing is that the power matches (or exceeds it by 10-15%), the type of refrigerant and overall dimensions. However, it will be necessary to resolder the copper tubes, since the seats differ between brands.
Why did the new compressor immediately burn out after installation?
Most often this happens due to moisture getting into the system (poor vacuum) or a clogged capillary tube. Also, the cause may be improper operation of the thermostat, which causes the motor to run without stopping and overheat.
How much does it cost to replace a compressor in the service?
The cost consists of the price of the unit itself and the work of the technician. On average, replacement costs 40-60% of the cost of a new refrigerator. The exact price can only be found out after diagnostics, since flushing the system may be required.