The issue of recycling old household appliances is often faces the owners of failed units, and one of the most valuable components that attracts attention is the compressor. It is electric motor inside the sealed case that it contains a significant amount of non-ferrous metals, in particular copper and steel, the cost of which at collection points may vary. The process of extracting these materials requires not only physical effort, but also an understanding of the internal structure of the unit, since structurally it is a complex unit assembled in a factory with a high degree of tightness.
It is worth immediately noting that standard disassembly while maintaining the functionality of the units is impossible here, since the goal is precisely obtaining scrap. The inner stator winding, made of copper wire, is of greatest interest to processors, but it can only be reached by destroying the outer casing. Many beginners mistakenly believe that it is enough to simply unscrew a few bolts, but the reality is that the body is most often welded or soldered, which requires the use of special tools.
Before starting any work, it is necessary to ensure safety, since residual pressure or oil may remain inside the system, and the process of metal destruction itself creates a risk of injury. Hermetic compressor is not intended to be opened by the user, so all actions are performed at your own peril and risk. In this article, we will look in detail at the dismantling steps, the necessary tools and technical features of various types of motors, so that you understand what exactly you will have to face.
Internal structure and types of compressors
Before picking up the tools, it is important to understand what exactly is inside the metal “can.” The basis of the design is electric motor, which drives the piston group that pumps the refrigerant. Most household refrigerators use piston units, where the motor and compressor part are located vertically or horizontally inside a single sealed housing filled with inert gas or oil to lubricate rubbing parts.
There is a division into linear and crank mechanisms, but from the point of view of copper mining, this difference is secondary. The main thing is the design of the stator and rotor. Stator winding wound with copper wire, which is the target resource. The rotor, in turn, is made of electrical steel plates. In some modern models, there may be inverter compressors, where the winding can be made using less copper or replaced with aluminum, which significantly reduces the final output of non-ferrous metal.
⚠️ Attention: Inside the compressor housing there is always technical oil, which is a toxic waste. When opened, it may spill, so work should be carried out on a prepared surface using absorbent materials or containers to collect liquid.
It is also worth mentioning the refrigerant. Although older refrigerators used freons, which escape when depressurized, modern models may use mixtures that require caution. Before starting disassembly, it is recommended to make sure that the system is completely depressurized and the pressure inside is equal to atmospheric pressure in order to avoid a sudden release of gases or oil at the first cut.
Required tools and safety measures
For effective and safe disassembly sealed unit you will need a set of specialized tools, since ordinary household scissors or hacksaws will be ineffective here. The main emphasis is on force and cutting metal, so the presence of protective equipment is a must. Sparks, flying chips and sharp metal edges pose a real threat to the eyes and skin.
The basic set of equipment should include:
- 🔨 A grinder (angle grinder) with metal discs is the main tool for quick opening housing.
- 🪚 Metal hacksaw - for more accurate work or if there is no access to electricity.
- 🔧 Set of wrenches and screwdrivers - for dismantling external elements, terminals and start relay.
- 🛡️ Safety glasses and gloves are a mandatory minimum for protection from chips and oil.
- 🔥 Blowtorch or gas torch - may be required to warm up coked compounds or burn off insulation (with caution).
Particular attention should be paid to electrical safety. If you plan to use a power tool in a garage or yard, make sure the wiring is in good working order and grounded. Working with grinder requires a steady hand and reliable fixation of the compressor itself, for example, in a vice or stop, to prevent it from moving at the time of cutting.
⚠️ Attention: Do not try to disassemble the compressor connected to the electrical network or immediately after work. Let it cool completely and make sure that the capacitors in the starting circuit are discharged to avoid electric shock.
In addition, the room should be well ventilated. When wire insulation heats up or oil residues burn, caustic smoke containing harmful substances may be released. Using a respirator would be a wise addition to safety glasses, especially if the process involves thermal exposure to internal components.
Stages of dismantling external elements
The process of extracting copper begins not with cutting the body, but with carefully removing the attachments. The first step is to disconnect the start and crank relays, which are usually attached to the back of the case. These elements contain their own windings and copper contacts, which are also valuable, although in a smaller volume.
To dismantle the relay you need:
- 🔌 Remove the protective plastic casing, if any.
- 🔩 Unscrew the mounting screws or carefully loosen the fixing ones clamps.
- 🧵 Disconnect the wires, having first memorized or photographed the connection diagram.
- 🧹 Clean the contacts from oxides for subsequent sorting.
Next, you should remove the copper tubes suitable for the compressor housing. They are soldered to the suction and discharge pipes. By cutting them with a pipe cutter or hacksaw, you will get additional grams of copper, and also protect yourself from possible freon residues. The tubes often have solder that can be heated with a torch for cleaner dismantling, but it is easier to simply saw them off at the very base.
It is important to remove all external fasteners, including bolts, washers and rubber shock absorbers. Rubber and plastic must be sorted and disposed of separately, since they are ballast. Clean metal is valued higher, so pre-sorting will save time at the collection point. After removing all external elements, you will be left with a “bare” metal cylinder, ready for the main stage of work.
☑️ Preparation for opening
Opening the sealed housing
The most labor-intensive and dangerous stage is the destruction of the weld or body. Factory welding ensures a tight seal, but for us it is an obstacle. There are two main approaches: a neat cut along the equator (seam) or rough cutting of the body into pieces. The first option requires more precision, the second requires less time, but more effort to remove the insides.
When using grinders it is necessary to make a cut along the perimeter of the weld separating the upper and lower hemispheres of the body. It is important not to damage the internal stator windings at this stage, although this often happens during rough disassembly. If you want to maintain the integrity of the windings for easier extraction of copper, try to guide the disc strictly along the seam, controlling the depth of the cut.
In some models, the body does not have a pronounced seam and is a solid elongated structure. In this case, you have to resort to radical measures: make several longitudinal cuts, turning the cylinder into petals, which are then bent. This allows you to gain access to the internal “filling” - the stator with the winding and the rotor.
What to do if the disk is jammed?
If the grinder disk is jammed in the metal, under no circumstances try to sharply pull the tool. Turn off the power, wait for the disk to stop completely and carefully, using a wedge or a second grinder, release the disk to avoid injury or breakage of the tool.
After opening, you will be presented with an internal structure: in the lower part there is often oil, and the engine itself is mounted on springs or rigid supports inside the casing. The entire engine must be removed. To do this, you may need to cut the supply wires inside the housing or unscrew the internal fasteners, if accessible.
Extracting copper from the stator and rotor
After the electric motor is removed from the housing, the process of obtaining the target metal begins. The stator is a package of electrical steel plates, in the grooves of which there is copper winding. You can’t just pull out the wire - it sits tightly in the grooves and is covered with varnish. There are several methods for extracting copper, each of which has its own characteristics.
The most common method is mechanical. To do this, it is necessary to cut or chop down the wires on one side of the stator (usually from the end where the frontal parts of the winding are visible). After this, bundles of copper wire can be pulled out from the opposite side. However, due to the varnish coating and dense laying, the wire often breaks, and the process takes a lot of time.
A more effective, but dirty method is thermal. The winding can be burned out by heating the stator to high temperatures. The varnish will burn off and the copper will become more malleable, making it easier to remove. However, this method leads to a loss of copper quality (it can oxidize) and emits a huge amount of toxic smoke from the combustion of insulation.
Comparison of copper extraction methods:
| Method | Labor costs | Copper quality | Environmental friendliness |
|---|---|---|---|
| Mechanical (cut) | High | High (gloss) | High |
| Thermal (burning) | Average | Medium (oxidation) | Low (smoke) |
| Chemical (solvents) | Low | High | Medium (reagents) |
The rotor, unlike the stator, contains practically no copper. It is a set of steel plates filled with aluminum (in asynchronous motors) or copper winding (in commutator motors, which is rare in refrigerators). The main mass of the rotor is electrical steel, which is sold as black scrap. Separating steel and aluminum in the rotor is usually not economically feasible due to small volumes of non-ferrous metal.
Sorting and assessing scrap output
After disassembly is complete, you will have several piles of material in front of you: copper wire, steel (housing, stator and rotor plates), aluminum (if present in the rotor or tubes) and mixed scrap. To get maximum profit, sorting must be done correctly. Scrap metal collection points strictly regulate categories, and mixing metals will result in payment at the price of the cheapest component.
Copper wire should be cleaned of any remaining insulation, varnish and solder. The purer the metal, the higher its category. “Mix” (copper with insulation) costs much less. The steel body and plates belong to the category of “black scrap” (dimensional or thin sheet), the price of which is significantly lower than for non-ferrous metals.
When weighing, it is worth considering that the actual copper yield is approximately 8-12% of the total mass of the compressor. The rest is heavy steel and oil. For example, from a compressor weighing 10 kg you can get about 1-1.2 kg of copper, the rest will be ferrous metal. These figures may vary depending on the model and year of manufacture of the refrigeration unit.
⚠️ Attention: Do not try to deceive the receivers by hiding steel or weights inside copper coils. Experienced workers at collection points can easily identify mixing, which can lead to a conflict and refusal to accept the entire batch of scrap.
It is better to store cut metal in a dry place, sorted into bags or boxes. Copper tends to oxidize, acquiring a dark coating, which can slightly reduce its value, therefore storage without protection is not recommended. It is more profitable to hand over scrap in large quantities accumulated from several refrigerators in order to compensate for the costs of tools and time.
Does the brand affect the amount of copper?
Yes, old Soviet compressors often contained more copper in the windings compared to modern Chinese counterparts, where aluminum or a smaller cross-section are often used to save money wires.
Frequently asked questions (FAQ)
How much copper can you really get from one compressor?
On average, the copper output is from 0.5 to 1.5 kg, depending on the power and engine model. Older large models can contain up to 2 kg, modern ones - less. The exact weight depends on the thickness of the wire and the number of turns laid down by the manufacturer.
Is it possible to disassemble a compressor without a grinder?
Theoretically, you can use a hacksaw and a chisel, but this will take 3-4 times longer and require significant physical effort. The grinder is the standard for such work due to the speed and efficiency of the cut.
Is the gas inside the compressor dangerous when cutting?
In old refrigerators that have been sitting for a long time, the pressure is usually equal to atmospheric pressure. However, if the unit has recently been operated or has been refilled, there may be residual pressure there. It is recommended that before cutting, you carefully drill a hole in the housing (in an inconspicuous place) to vent gases, and do this in a ventilated area.
Does it make sense to disassemble an inverter compressor?
Inverter compressors often have a different design and may contain less copper, as well as more complex electronic components. The process of disassembling them can be more complicated, and the yield of non-ferrous metal can be unpredictable. Often they are handed over entirely as a complex unit.
Where should the oil from the compressor be put?
Technical oil is a hazardous waste. It should not be poured down the drain or onto the ground. Collect it in a sealed container and hand it over to special collection points for used oils or hazardous waste collection points, if there are such in your region.