The question of how to disassemble a compressor from a refrigerator often arises among those who are trying to independently diagnose a malfunction or find the cause of a breakdown. However, it is important to immediately understand that the standard sealed piston unit installed in most household refrigerators is not intended for disassembly at home for the purpose of subsequent repairs. Factory welding of the housing is designed for one-time use, and opening it violates the integrity of the system.
However, knowledge of the design is necessary for proper disposal, conversion of the device into a compressor for airbrushing or painting, or for in-depth diagnostics before replacement. The process requires specific tools and strict adherence to safety precautions, since there may be oil under pressure and refrigerant residues inside.
Before proceeding with any manipulations with electric motor and the mechanical part, make sure that the device is disconnected from the power supply for at least a day. This will allow the oil to drain into the crankcase and reduce the risk of aggressive liquids splashing when opened. In this article we will look at the stages of dismantling and opening the case, and also explain why complete disassembly is often impractical.
Design and principle of operation of a sealed unit
The refrigerator compressor is a complex mechanism where electric motor and the piston group are placed inside a single steel casing. This design is called hermetically sealed, since all moving parts operate in an atmosphere of inert gas and refrigerant vapor. This solution allows you to minimize freon leaks and reduce the noise level when operating household appliances.
There are three main components inside the casing: itself compressor (piston group), an electric motor and a start-protection relay. All of them are mounted on springs or rubber shock absorbers to dampen vibrations. The engine shaft is directly connected to the crank mechanism, which drives the pistons.
The oil located at the bottom of the casing splashes when the shaft rotates and lubricates the rubbing parts. The pressure inside the housing during operation can reach 15-20 atmospheres, and the temperature of the motor windings can be 110-120 degrees Celsius. That is why opening requires caution: sharp a difference in pressure or temperature can lead to injury.
⚠️ Attention: There may be residual pressure inside the compressor. Before starting work on sawing the case, you must make sure that the device has completely cooled down and is not under voltage.
Necessary tools and precautions
For high-quality and safe dismantling of the compressor from the refrigerator, as well as subsequent opening of its case, you will need a set of specialized tools. A regular set of screwdrivers will not be enough here, since the main task will be to cut the weld without damaging the internal components.
The list of necessary equipment includes:
- 🔧 Angle grinder (grinder) with a thin cutting disc for metal.
- 🔨 Hammer and chisel or a powerful flat-head screwdriver to open the seam.
- 🔌 Multimeter for checking the windings and circuit integrity.
- 🧤 Protective gloves and glasses to protect against metal shavings.
Before starting work, it is necessary to dismantle the unit itself from the frame of the refrigerator. To do this, copper tubes discharge and suction are cut. It is important to do this carefully so as not to damage the evaporator and condenser if you plan to continue using the refrigeration circuit.
You will also need to drain the old compressor oil. To do this, turn the compressor over and wait until the liquid completely flows into the prepared container. Oil can be aggressive, so use chemical-resistant containers and work in a ventilated area.
The process of removing the compressor from the refrigerator frame
Removing the unit from the frame is the first stage, which must be approached responsibly. The compressor is mounted on four legs with rubber bushings that dampen vibration. Over time, the rubber hardens, and removal may require effort.
First you need to disconnect the electrical contacts. The starting and protective relay is usually simply slipped onto the motor contacts and secured with a bracket or strip. Carefully remove the plastic casing, remember or photograph the connection diagram so that when installing a new device you do not mix up the wires.
☑️ Dismantling the unit
Then the copper tubes are cut. This should be done with wire cutters or a pipe cutter as close to the compressor housing as possible, but without damaging the housing itself. After the pipes are freed, the compressor is removed from the rubber shock absorbers. If the legs are stuck, you can carefully pry them off with a mounting spatula.
At this stage, it is already possible to carry out an initial diagnosis. Check the winding resistance with a multimeter. Normal values for household models vary between 10-30 Ohms for the starting winding and 10-15 Ohms for the working winding. If the device shows a break or short circuit, further disassembly makes sense only for disposal or use of individual parts.
Opening the sealed housing (sawing)
The most difficult and crucial moment is the violation of the tightness of the weld. The factory welding is done very well, so simply “opening” the lid will not work. It is necessary to use a grinder.
The cutting technique requires precision:
- Install the compressor firmly, fixing it with a vice or stops (without squeezing the body too much).
- Make a shallow cut along the entire perimeter of the weld connecting the upper and lower bowls.
- Do not cut right through the metal to avoid damaging the internal windings or valve plates.
- After going through the circle, gently tap the cut line with a hammer to open the joint.
An alternative method involves using a chisel. After filing the seam with a grinder in several places, a chisel is inserted into the groove, and with hammer blows they try to split the welded joint. This method is rougher and requires great physical strength.
⚠️ Attention: When sawing, a lot of metal dust and sparks are generated. It is strictly forbidden to carry out work near flammable substances, as oil and refrigerant vapors may ignite.
After successfully removing the top cover, the internal structure will open in front of you. You will see the stator windings, the motor rotor and the piston group itself, mounted on springs. Be careful: the edges of the metal case after cutting are very sharp.
Diagnostics of internal components
Open access allows you to visually assess the condition of the insides. First of all, pay attention to the color of the motor windings. If they are blackened or have traces of burning, then interturn short circuit has already happened, and such a unit cannot be repaired.
Next, check the mechanical part. The piston group in household refrigerators is often made of light alloys. When jamming (hydraulic shock), deep scuff marks may remain on the pistons and cylinders. The presence of chips at the bottom of the case also indicates serious mechanical wear.
Why can’t the seal be restored?
It is impossible to weld the case back at home. This requires argon welding in an inert gas environment, evacuation of the system and charging with refrigerant on a special stand. The cost of such work exceeds the price of a new compressor.
It is also worth inspecting the valve plates. These are thin metal blades that open and close the gas holes. If they are deformed or broken, the compressor will not produce the required pressure. Replacing valves is possible, but requires high precision and selection of plate thickness.
The table below shows typical faults and their signs during disassembly:
| Fault | Visual sign | Repairability |
|---|---|---|
| Winding break | Blackening, burning smell | No (motor replacement) |
| Jagging | Scuffing on the cylinder, broken connecting rod | No (unit replacement) |
| Wear of valves | Deformation of plates | Partially (rarely) |
| Contact burnout | Soot on the relay | Yes (relay replacement) |
Use of a dismantled compressor
Often compressors are disassembled not for refrigerator repair, but for recycling. A powerful and compact unit is perfect for creating a compressor for airbrushing, inflating tires or blowing parts. In such cases, the tightness of the housing is not required, and sometimes even interferes.
To convert it to a pneumatic tool, they usually remove the internal filling, leaving only the electric motor, or use the entire unit, connecting a receiver (tank) and a gearbox to the outlet. It is important to install an oil separator filter, since the compressor will throw out oil along with the air.
If your goal is to gain access to the copper winding for delivery to non-ferrous metal, then after opening the housing the stator is removed entirely. To do this, you often have to disassemble the stacked core plates or cut the winding wire. Copper makes up a significant portion of the weight of the device and has a high return value.
When assembling homemade installations, it is important to remember the cooling system. In the refrigerator, the compressor is cooled by freon vapor and oil washing. In open mode or during intensive work in a homemade case, it may overheat. It is recommended to install an additional fan or take breaks in operation.
Is it worth trying to put it back together?
The answer to this question is clear: it is impossible to put a sealed compressor back together at home with a guarantee of reliability. Even if you manage to weld the body, the problem of vacuuming will remain. There should be no air or moisture in the system, otherwise acid will form during operation, which will quickly damage the unit.
In addition, accurate refrigerant charging is necessary. The amount of freon is measured in grams, and a deviation of even 5-10 grams can lead to improper operation or freezing of pipelines. Specialized equipment for these purposes costs more than a new compressor.
If you discover a malfunction at the stage of diagnosing internal components, the only correct solution is to purchase a new similar unit. Modern compressors are relatively inexpensive, and replacing them takes about 30-40 minutes from an experienced technician.
Attempts to “revive” a jammed compressor by applying increased voltage or turning the shaft manually give only a temporary effect. The lifespan of such a unit is calculated in hours, after which it finally fails, often burning out along with the refrigerator wiring.
FAQ: Frequently Asked Questions
Is it possible to change the oil in a refrigerator compressor?
Theoretically, yes, but only if the compressor has already been disassembled or has a service pipe (which is rare for household models). In a standard sealed housing, changing the oil requires complete opening, flushing and subsequent evacuation, which makes it easier to replace the entire unit.
Why does the compressor hum but does not start?
Most often this indicates a jammed piston group or a faulty start relay. A break in the starting winding is also possible. Diagnostics with a multimeter and checking the free movement of the shaft are required.
Is it dangerous to open the compressor yourself?
Yes, it is dangerous. There may be pressure inside, oil vapors are toxic, and when working with an angle grinder there is a risk of injury. In addition, residual refrigerant can be flammable when mixed with air in the presence of a spark.
Which tool is best suited for opening?
The best result is obtained by using an angle grinder (grinder) with a thin disk. This allows you to make an even cut along the seam without damaging the internal parts, unlike rough knocking down with a chisel.
Is it possible to use a car compressor instead of a refrigeration one?
No, car compressors (for inflating tires) are not designed to create a vacuum and work with refrigerants. They will not be able to ensure the circulation of freon in the refrigerator circuit.