Removing a compressor from an old refrigerator often becomes a necessity, be it the desire to obtain non-ferrous metals for scrapping, the need for spare parts to repair another unit, or simply the disposal of bulky equipment. The old one refrigeration compressor is a sealed steel “pot”, inside which hides an electric motor and a piston group immersed in oil. The process of opening it or disconnecting it from the system requires not only physical effort, but also compliance with strict safety measures, since residual pressure may remain inside.
Before you grab the tools, it is important to understand that most household models, be it Atlant, Stinol or Biryusa, have a similar motor-compressor design. This simplifies the task, but the age of the equipment can play a cruel joke: rust and soured joints can turn a simple operation into a multi-hour ordeal. In this article we will analyze in detail the stages of preparation, the necessary tools and the algorithm of actions itself, which will allow you to safely dismantle and disassemble the unit.
It is worth immediately noting that complete disassembly of the compressor housing at home without specialized machine is practically impossible or extremely dangerous, since the body is welded in a circle. Therefore, “disassembly” most often means either carefully detaching the unit from the frame of the refrigerator while maintaining its integrity, or mechanical sawing of the body with a grinder to remove windings and copper tubes. The choice of path depends on your final goal.
Necessary tools and safety measures
Working with technically complex and potentially dangerous equipment requires the correct equipment. Even if you simply disconnect the motor from the frame, the risk of cutting yourself on sharp metal edges or being injured by a flying part is quite high. To perform the task efficiently, you will need a set of plumbing tools, which can be found in the garage of most men who are interested in technology.
Particular attention should be paid to protecting the organs of vision and breathing. When working with an old refrigerator, especially if you plan to saw the body, metal dust and possibly old oil vapors are generated, which are strictly not recommended to be inhaled. If your goal is repair, then the cleanliness of the workplace and tools will be the key to success, since the entry of the smallest dust into the system is fatal for freon and the mechanism.
⚠️ Attention: Before starting any work, make sure that the refrigerator is completely disconnected from the power supply for at least 2-3 hours before disassembly. This is necessary to drain the oil into the lower part of the crankcase and reduce the pressure in the system.
To perform dismantling and subsequent disassembly you will need:
- 🔧 A set of open-end and ring wrenches (sizes 8, 10, 12, 14 mm)
- 🔨 Hammer and chisel (for knocking down rust or careful opening)
- 🪚 Angle grinder (grinder) with a metal disc
- 🔩 Screwdrivers (flat and Phillips) for removing terminal boxes
- 🧤 Thick work gloves and safety glasses
If you plan to open the case to obtain copper, the angle grinder will become your main tool. In case it is necessary to keep the compressor working (for example, for conversion into a compressor for airbrush), a grinder is not needed, but pipe cutters and soldering tools will be required to carefully disconnect the lines.
Preparing equipment and removing refrigerant
The first stage of any serious work with refrigeration equipment is preparation. An old refrigerator motor is not just an electric motor, it is part of a closed system under pressure. Even when not working, gas may remain there. In today's environment of environmental responsibility, simply "releasing the freon into the atmosphere" is considered the wrong approach, although in old instructions this was often ignored.
First, you need to roll out the refrigerator to a well-ventilated area, preferably outside or in a garage with an open gate. If the unit is still at least a little cold, you cannot put a load on the compressor during disassembly. You need to find the technical pipe; it is usually located in the lower rear part of the refrigerator, next to the motor. This is a sealed copper tube.
To safely remove any remaining gas and oil that may splash out under pressure, you need to carefully file one of the copper tubes going to the compressor. This is best done with a needle file or a hacksaw, avoiding the use of open flames near possible leaks. As soon as the tightness is broken, you will hear a characteristic hissing sound.
After waiting until the pressure is equal to atmospheric pressure, you can proceed to dismantling the assembly itself. It is important here not to damage the electrical part if you plan to reuse the motor. The terminal box is usually secured with three screws or latches; it must be removed by first photographing or sketching the wire connection diagram, so as not to confuse the starting winding during future connections. data-i="84">The process of removing the engine from the frame of an old refrigerator is technically simple, but may require significant physical effort due to corrosion of the fasteners. The compressor is usually mounted on a metal frame by means of four springs or rubber shock absorbers, which dampen vibration when the motor is running. Over time, the rubber hardens and the metal rusts, which complicates the task. working and starting winding for future connection.
Removing the compressor from the refrigerator frame
The process of removing the engine from the frame of an old refrigerator is technically simple, but may require significant physical effort due to corrosion of the fasteners. The compressor is usually mounted on a metal frame by means of four springs or rubber shock absorbers, which dampen vibration when the motor is running. Over time, the rubber hardens and the metal rusts, making the task more difficult.
First, you need to unscrew all visible bolts and nuts holding the unit. If the threads are stuck, use a penetrating lubricant (such as WD-40 or its equivalent) by applying it to the joint and waiting 10-15 minutes. Sharp blows with a hammer on the fasteners will also help loosen the rust. The main thing is not to strip the threads if you plan to reuse the old bolts.
After releasing the fastening tabs, the compressor can still stay on the tubes. Copper is a soft metal, and if tugged, the tubes can burst right at the base, requiring further soldering. Therefore, be careful while supporting the weight of the motor with your other hand. In some models, such as old ZIL or Minsk, the compressor can be welded to the frame, which will require the use of a grinder to cut off the supports.
☑️ Dismantling checklist
When the compressor is in your hands, inspect it visually. The presence of deep corrosion on the body may indicate that there has been moisture inside for a long time, and it is better to immediately send such a unit for disposal. If the case is dry and intact, it can be used for further experiments or repairs.
Opening a sealed case: technologies and risks
If your goal is to obtain non-ferrous metal (copper and steel) or you want to replace the insides of a burnt out motor, you will have to open the sealed case. Factory welding is done in a circle and provides the absolute tightness required for high pressure work. Simply “unscrewing” nothing will work here.
The most common method in garage conditions is the use of an angle grinder (grinder). It is necessary to make a careful cut along the weld connecting the upper and lower bowls of the body. It is important not to damage the internal stator windings and rotor if you want to maintain their integrity. The depth of the cut must be controlled very carefully.
⚠️ Attention: When sawing the body with a grinder, be sure to use a respirator. There may be asbestos dust inside (in very old models) or toxic combustion products of varnish and oil.
There is also a less accurate but quick method - punching through the body with a chisel and hammer along the perimeter of the seam. This method is only suitable for those who want to scrap the metal, since the deformation of the bowls will be severe, and it will no longer be possible to assemble them back hermetically. For repair this option is absolutely not suitable.
In some cases, to avoid sparks and heating, craftsmen use a hand hacksaw for metal, making cuts in a circle. This is time-consuming and labor-intensive, but safe for the contents. After the seam has been passed, the top cover can be removed, gaining access to the “filling.”
Removing windings and non-ferrous metals
Inside the case you will see a stator with copper coils wound on it and a rotor located in the center. It is copper that represents the greatest value when recycled. To extract it as efficiently as possible, you need to remove unnecessary elements, such as electrical steel plates, which weigh down the structure.
The winding is usually varnished and sits tightly in the stator grooves. You can't just pull it out with your hands. There are several ways to release copper:
- 🔥 Heating: Firing the coils with a gas torch burns off the varnish and insulation, after which the copper is easily separated. However, this produces acrid smoke.
- 🪓 Mechanical: Cutting off one side of the coil with an ax and pulling out bundles of wire on the other side.
- 🧪 Chemical: Using aggressive acids to dissolve varnish (requires special care and disposal of reagents).
The rotor also contains copper (in the form of a short-circuited winding) and steel. In older engines there are more copper plates in the rotor, in modern engines there are fewer. Stator plates, if they are not damaged by rust, can also be passed as ferrous metal, having previously separated them from copper.
How much copper is in a compressor?
On average, from one standard household compressor weighing 10-12 kg you can get from 1.5 to 2.5 kg of pure copper. The exact amount depends on the year of manufacture and the power of the motor: in old Soviet models there is more copper, in modern energy-efficient ones there is less, but the content of rare earth metals in the magnets is higher (if the motor is a new type).
After removing non-ferrous metals, the remaining steel “bowl” and plates should be sorted. Remember that mixing ferrous and non-ferrous metals when handing over significantly reduces the cost of scrap, so careful sorting is economically justified.
Assembly and conversion for reuse
If your goal was not scrap, but the creation of a compressor for inflating tires, airbrushing or pneumatic tools, then the process looks different. You do not need to open the housing, but only properly preserve and connect the unit. Old refrigeration compressors do an excellent job of creating pressure up to 6-10 atmospheres.
For the conversion, you will need to install an adapter, a check valve (so that air does not flow back into the engine when stopping) and a receiver (a tank for storing air) on the compressor outlet tube. Old fire extinguishers or gas cylinders are often used as a receiver, but their preparation requires separate, very careful instructions for cleaning and testing for strength.
| Parameter | Refrigeration mode | Compressor mode (air) |
|---|---|---|
| Working pressure | up to 10-15 atm (freon) | up to 6-8 atm (air) |
| Lubricant | Oil inside the crankcase | Oil level control required |
| Cooling | Natural (body) | Forced airflow required |
| Moisture separation | Not required (dry freon) | A moisture separator is required |
When assembling a homemade compressor, it is critical to provide a cooling system, since when air is compressed, the housing will heat up much more than when working with freon. Also, a filter-moisture separator must be installed at the air outlet, otherwise the air stream will spit oil, which is unacceptable for painting work or inflating tires.
The electrical connection diagram remains standard: the starting relay and capacitor (if your model has one) must be connected correctly. Errors in connecting the starting winding can lead to humming of the motor and its rapid combustion.
Frequent errors during disassembly and their consequences
In the process of dismantling and disassembling, beginners often make mistakes that nullify all efforts or lead to injuries. One of the most common is an attempt to saw off the tubes with a hacksaw without first releasing the pressure. Residual gas can suddenly escape, spraying oil throughout the room.
Another mistake is neglecting to mark the wires. Having disconnected the terminals, many people forget where the zero was, where the phase was, and where the starting winding was. As a result, when you turn it on for the first time, the motor hums, but does not start, or the starting relay burns out. Always label the wires or take a photo before dismantling.
⚠️ Warning: Never attempt to start the compressor “directly” without a start relay or capacitor. This is guaranteed to lead to the windings burning out in the first seconds of operation.
It is also worth mentioning the error when sawing the body. If you touch the inner winding with an angle grinder, you will damage the varnish on the wires. As a result, when turned on, an interturn short circuit will occur and the motor will burn out. Therefore, if you are not confident in your tool handling skills, it is better not to take risks and limit yourself to external dismantling.
Proper disposal or second life of an old refrigerator motor is not only a saving of resources, but also an excellent practical experience. By observing safety precautions and following the instructions, you can safely disassemble the unit, obtaining valuable materials or new tools for the workshop.
FAQ: Frequently asked questions
Is it possible to hand over the entire compressor to a metal collection point?
Yes, most collection points accept entire compressors as ferrous scrap, but the price will be below. If you open the case yourself and remove the copper winding, separating it from the steel, revenue can increase 2-3 times.
Is oil from an old refrigeration compressor dangerous?
Mineral or synthetic oil from the compressor itself is not highly toxic, but it contains metal wear products and possible refrigerant impurities. You need to work with it with gloves, and it should be disposed of as used technical oil; pouring it down the drain is prohibited.
Why does the compressor hum after disassembly and reassembly?
If after alteration or connection the motor hums but does not turn, most likely the start relay is faulty, the piston is jammed due to lack of oil or is connected incorrectly windings Also, the reason may be the lack of pressure at the outlet (air flows in the opposite direction) if a check valve is not installed.
Which tool is best suited for cutting copper pipes?
The ideal tool is a special pipe cutter. It gives an even cut without burrs and does not create chips that could get inside the system. A hacksaw is acceptable, but requires careful cleaning of the edge. It is not recommended to cut tubes with a grinder due to the risk of melting the edges.