The situation when a refrigeration unit stops freezing often leaves the owner with a choice: call a technician or try to solve the problem on his own. Disassembling a compressor, which is often called an “engine” in everyday life, is a complex procedure that requires not only technical skills, but also an understanding of the principles of operation of sealed systems. Before proceeding with dismantling and opening the housing, it is necessary to clearly understand that modern units are designed as non-dismountable units, and their restoration is possible only in exceptional cases.
Interference with the internal structure piston or inverter mechanism without special equipment often leads to the final failure of the equipment. However, for enthusiasts who want to study the design of the unit or try to replace the valve group, there is a certain algorithm of actions. It is important to understand that we are talking about high pressure and electric current, so ignoring safety rules is unacceptable.
The purpose of this manual is to provide comprehensive information on how to safely remove and open the compressor without harming yourself and others. We will look at the necessary tools, preparation steps and the process of dismantling the internal components. Remember that successful disassembly is only half the battle; assembly and sealing require even higher qualifications.
Necessary tools and safety measures
Before starting any work with electrical equipment and mechanical components, it is necessary to prepare the workplace. You will need a set of plumbing tools, including pliers, screwdrivers with various blades and a hammer. Particular attention should be paid to protecting hands and eyes, since opening the case may cause metal fragments or oil splashes to fly out.
To work with a sealed casing, you will need a specialized tool, such as a grinder with a thin disk or a hacksaw. It would also be useful to have a multimeter to check the windings electric motor and a pressure gauge if you plan to further check the pressure. Without these devices, diagnostics will be incomplete.
⚠️ Attention: Before starting work, be sure to disconnect the refrigerator from the power supply and wait until the capacitors in the starting relay are completely discharged. Residual voltage can be life-threatening.
You should work in a well-ventilated area, since there may be technical oil inside the compressor, the vapors of which should not be inhaled in large concentrations. Prepare a container for draining the waste and a rag for cleaning.
- 🛠️ A set of screwdrivers and pliers for dismantling external elements.
- 🔪 A grinder or a hacksaw for cutting the body.
- ⚡ Multimeter for checking the integrity of electrical chains.
- 🧤 Protective gloves and glasses to prevent injury.
Preparation for dismantling the compressor
The first stage is to physically remove the unit from the refrigeration chamber. Typically the compressor is located at the bottom rear of the device, hidden by a protective casing. It is necessary to remove the back panel by unscrewing the mounting bolts and gain access to the black metal “tank”.
Before disconnecting the tubes, you should bleed off the refrigerant. In the factory, this is done through a Schrader valve, but at home, you often have to carefully file one of the copper tubes. This must be done carefully so that a spark from the tool does not ignite freon vapors, although modern refrigerants are less flammable.
After bleeding the gas, you need to disconnect the electrical contacts. Remove the start and safety relay by carefully releasing the retaining clips. Remember or photograph the wiring diagram so that during reassembly (if it is planned) you do not mix up the winding contacts.
Next, you should unsolder the copper tubes going to the condenser and evaporator. To do this, use a gas torch or a powerful soldering iron with solder. After disconnecting all communications, the compressor can be removed from the frame by unscrewing the four mounting nuts with rubber shock absorbers.
- 🔌 Disconnect the device from the mains and remove the back cover.
- 💨 Carefully release the refrigerant in a ventilated place.
- 🔌 Remove the starting relay and disconnect the wires.
- 🔥 Unsolder the copper tubes and remove the unit from the frame.
Opening the sealed casing
The most important and time-consuming step is breaking the seal body weld. The factory welding is done very well, so you can’t just unscrew the casing. There are two main methods: mechanical cutting and knocking out the seam.
When using a grinder, you need to make a circular cut around the perimeter of the weld. It is important not to damage the internal components, so the cutting depth is controlled visually and audibly. An alternative method is to knock out the locking joint with a hammer and chisel, which requires considerable physical strength and dexterity.
Why can’t you just unscrew the bolts?
Modern compressors are manufactured using “forever” technology. The housing halves are factory welded to ensure an absolute seal under high pressure. There are no bolted connections to eliminate the possibility of refrigerant leakage through the threads during many years of operation.
After the seam is passed or knocked down, the top cover is removed. Inside you will see a submersible motor and piston group filled with oil. Be prepared for the oil to spill out, so use a wide container.
⚠️ Attention: Use safety glasses when sawing the body. Metal shavings and sparks can get into your eyes or skin.
Removing internal components
Inside the housing there is a main mechanism consisting of a stator, rotor, crankshaft and piston group. All these elements are mounted on springs or rigid supports inside the casing. The first step is to remove the valve group, which is responsible for the injection and suction of gas.
The valves are bolted to the end of the cylinder. Their condition directly affects the performance of the compressor. If the valve petals are warped or broken, the engine will run but not produce the required system pressure. Replacing valves is one of the most common reasons for disassembly.
Removing the rotor and shaft may require a puller or careful knocking out. Pay attention to the condition of the plain bearings. If scuffs or wear are visible on them, then restoring the unit makes no sense, since it is impossible to ensure tightness and balancing at home.
- 🔩 Unscrew the bolts securing the valve group.
- 🔍 Inspect the valve petals for cracks.
- ⚙️ Check the condition of the bearings and shaft.
- 🧹 Clean the insides from carbon deposits and metal shavings.
Diagnostics of faults in the electrical part
After gaining access to the stator windings, you can carry out a detailed diagnosis of the electrical part. Often the problem lies not in mechanics, but in an interturn short circuit or open circuit. To check, use a multimeter in resistance measurement mode.
It is necessary to “ring” the three contacts coming out of the engine. The resistance between the starting and operating windings, as well as between each winding and the housing, must correspond to certain values. If the device shows zero or infinity, the winding is faulty.
It is also worth inspecting the wires for insulation melting. Overheating could occur due to jamming of the mechanism or problems with the start relay. If the windings are burned out, rewinding the motor at home is almost impossible due to the complexity of installation and balancing.
Table of common problems and solutions
To systematize data on possible malfunctions identified during disassembly, it is convenient to use a summary table. It will help determine whether it is worth continuing the repair or whether it is easier to replace the entire unit.
| Malfunction | Symptoms | Possible solution | Difficulty |
|---|---|---|---|
| Piston jamming | Humming, no startup | Wedging, oil change | High |
| Winding break | No resistance | Rewind or replacement | Critical |
| Valve wear | Weak pressure, noise | Replacement of valve group | Average |
| Bearing wear | Knock, vibration | Replacement of bushings (rarely) | High |
Analysis of the table shows that most mechanical damage requires complex intervention. The easiest way is to replace the valves, but even this operation requires precision. If the problem is in the electrical system or the geometry of the cylinders, the repair becomes economically unfeasible.
Assembling and sealing the unit
If the parts are replaced and the defects are eliminated, the assembly stage begins. This is the most critical moment, since the further operation of the refrigerator depends on the quality of sealing. The body halves must be aligned perfectly evenly so that the weld seam fits correctly.
Argon welding or a powerful gas torch with solder is used for connection. The seam must be continuous, without microcracks and pores. After welding, the compressor must be checked under nitrogen pressure for leaks.
☑️ Assembly checklist
After successful pressure testing, the system is evacuated to remove moisture and air. Only after this can you fill the unit with freon and check its operation. You cannot start the compressor without a vacuum sealer - moisture will cause corrosion and freezing in the capillary tube.
⚠️ Attention: Self-filling the refrigerator with refrigerant requires a license and special equipment. Uncontrolled release of freon is harmful to the environment.
Is the game worth the trouble?
Disassembling a refrigerator compressor is a complex engineering process, which in 90% of cases ends with a complete replacement of the unit. Sealed units are not intended for maintenance, and opening them is more of an experimental nature.
If you do not have experience in refrigeration, attempting to disassemble them can only lead to a loss of time and money. However, for those who want to study the device piston group or revive a rare model, this path is open. The main thing is to follow safety precautions and soberly assess your strength.
In modern conditions, it is easier to purchase a new compressor of similar power and install it than to try to restore the old one. This guarantees the reliability and long life of your refrigerator. Repair is justified only if the equipment is unique or it is impossible to purchase a replacement.
Is it possible to disassemble a compressor without a grinder?
Theoretically You can try to knock out the lock seam with a hammer and chisel, but this requires enormous force and risks damaging the internal parts. A grinder or grinder significantly speeds up the process and makes the cut more controlled.
What kind of oil should be poured into the compressor after disassembly?
You should only use the special refrigeration oil specified in the model specification (usually mineral or polyester). Regular motor oil is strictly prohibited, as it freezes at low temperatures and is not compatible with refrigerants.
Why does the compressor heat up after assembly?
Excessive heating may indicate improper assembly, lack of the proper amount of oil, jammed mechanism or problems with the electrical part (interturn short circuit). Also, the reason may be the lack of normal cooling of the case.
Is it realistic to make a compressor from a refrigerator for the garage?
Yes, this is a popular option for using old units. After disassembling and removing excess automation, the compressor can be used as a source of compressed air for a spray gun or inflating tires, but the pressure will be limited by the design.
What to do if, after assembly, the compressor hums, but does not pump?
Most likely, the tightness of the valve group is broken or the suction and discharge pipes. It is also possible that during welding, scale got inside and blocked the valves.