The question about the content of precious and non-ferrous metals in household appliances often arises among those who plan to recycle an old unit or are engaged in professional repairs. The refrigerator engine, or motor-compressor, does contain valuable raw materials that can be taken to scrap metal collection points. However, the exact amount of copper varies depending on the manufacturer, year of manufacture and type of compressor.
On average, one standard household compressor contains from 1.2 to 2.5 kilograms of pure copper. This figure is the sum of the stator and rotor windings and, partially, the heat exchanger tubes, if they have not been cut previously. It is important to understand that the weight of “dirty” scrap and the yield of clean metal after cutting are different indicators that affect the final profit.
You should not rely on rough estimates, since modern models can differ significantly from Soviet-made equipment in terms of material consumption. In this article we will analyze in detail the design of compressors, methods for determining the weight of copper and the factors influencing this parameter.
Motor-compressor design and sources of copper
To understand where non-ferrous metal comes from, it is necessary to consider the internal structure of the unit. The main source of copper in the compressor is electric motor windings. They are located on the stator and are made of high purity copper wire coated with varnish insulation. It is this part that is of the greatest interest to scrap buyers.
The second important element is the rotor itself, which can also contain copper components in a squirrel-cage design, although asynchronous motors of household refrigerators often use aluminum or steel in combination with copper rings. In addition, copper pipes are connected to the engine through which the refrigerant circulates.
⚠️ Warning: There is oil inside the compressor, which may be toxic. When opening the sealed case (which is strictly not recommended to do at home due to the risk of explosion or poisoning), harmful fumes are released. Hand over the units as a whole or after professional cutting.
The third source is the connecting wires and starting relay contacts, although their contribution to the total weight of copper is minimal compared to the windings. Understanding the design helps to evaluate whether it is worth spending time on cutting yourself or whether it is easier to hand over the entire assembly.
Is it possible to extract copper with a magnet?
No, copper is diamagnetic and does not magnetize. However, the presence of a magnet in a motor (in the rotor or stator of some models) does not mean that the entire motor is made of magnetic metal. The steel of the body and the core are magnetic, but the copper winding is not.
Factors influencing the weight of copper in different models
The weight of copper is not a constant and depends on several technical parameters. Firstly, this compressor power. Large capacity refrigerators designed for commercial use or families with large numbers of people are equipped with more powerful motors. Accordingly, the cross-section of the winding wire and the number of turns in them increase, which directly affects the mass of non-ferrous metal.
Secondly, the era of production of the equipment matters. Soviet refrigerators, such as ZIL, Biryusa or Minsk, were famous for their maintainability and the use of a large number of high-quality materials. They often used copper where modern manufacturers use aluminum or composites for the sake of economy.
Thirdly, the type of refrigerant and the design of the heat exchanger also play a role. Old models ran on freons, which required certain heat transfer parameters, which affected the length and thickness of the copper tubes. Modern inverter compressors may have a different winding architecture to increase energy efficiency.
It is also worth considering the condition of the unit. If the refrigerator was under repair, the technician could replace the standard copper tubes with steel or aluminum ones, which would reduce the total weight of the non-ferrous metal upon delivery.
Comparative table: copper content in popular models
For clarity, we present data based on average weighing and cutting of various types of compressors. These numbers will help you figure out what to expect from a particular device.
| Compressor type / Model | Total unit weight (kg) | Weight of copper in windings (kg) | Weight of copper tubes (kg) |
|---|---|---|---|
| Soviet (AT-100, AT-120) | 18 - 22 | 1.8 - 2.2 | 0.4 - 0.6 |
| European (Danfoss, Secop) | 10 - 14 | 1.0 - 1.4 | 0.2 - 0.3 |
| Asian (LG, Samsung) | 9 - 12 | 0.8 - 1.2 | 0.15 - 0.25 |
| Inverter (modern) | 8 - 11 | 0.6 - 0.9 | 0.1 - 0.2 |
As can be seen from tables, old Soviet units are real “treasures” for non-ferrous metal collectors, containing almost twice as much copper as modern analogues. This is due to less efficient, but more material-intensive technologies of the past.
Modern manufacturers are striving to miniaturize and reduce the weight of the structure, which leads to a reduction in the amount of copper used. However, even 0.6 kg of pure copper is a valuable resource that can be recycled.
Methods for determining the amount of copper without opening it
It is impossible to know exactly how much copper is inside a sealed compressor tank without destroying it. However, experienced craftsmen and scrap metal acceptors use indirect valuation methods. The first method is weighing. Knowing the approximate weight of the empty housing and rotor (which are usually steel), you can subtract their mass from the total weight.
The second method is marking analysis. The compressor nameplate often indicates the power in watts or horsepower. There is an empirical relationship: the higher the power, the more copper is used in the windings. For example, 1/3 HP compressors. will contain less copper than 1/2 hp models.
You can also focus on the dimensions. A visually voluminous and heavy compressor with thick copper tubes at the outlet will most likely contain more non-ferrous metal than a light and compact analogue.
Economic feasibility and scrap price
The cost of delivery of compressors depends on current quotes on non-ferrous metal exchanges and the policy of a particular collection point. Typically, compressors are accepted under the category “copper in the engine” or “motor engine”, the price for which is lower than for pure burnt copper, but higher than for black scrap.
It is important to distinguish between the concepts of “output” and “purchase price”. Receiving points can accept entire compressors, assuming a certain percentage of copper output (usually about 10-15% of the weight of the compressor itself, not counting oil and steel casing). If you decide to sell a disassembled engine, the price per kilogram will be higher.
⚠️ Attention: Non-ferrous scrap metal prices are volatile. They can change daily depending on the dollar exchange rate and demand on the world market. Before handing over the batch, check the current price list in your region.
Some collection points require the presence of oil in the compressor to confirm that this is a refrigeration unit and not an electric motor from a machine. In other cases, on the contrary, they require draining the oil. This needs to be clarified in advance.
Rules for safe preparation for delivery
If you decide to hand over a refrigerator or compressor, you must follow certain safety rules and environmental standards. First, the compressor must be disconnected from the power supply. Secondly, freon should not escape from the system into the atmosphere, since many refrigerants destroy the ozone layer.
To independently prepare for delivery, follow these steps:
- 🔌 Unplug the refrigerator and let it stand for several hours.
- ✂️ Cut the copper pipes compressor with pliers, moving 5-10 cm away from the housing (do not open the housing itself!).
- 🛢️ Drain the technical oil into an airtight container through the cut tubes (lift the compressor).
- 🧹 Wipe the outer surface from dirt and oil residues.
☑️ Preparing the compressor for delivery
It is better to remove the starting relay and capacitor separately. The relay also contains some copper, but it is mostly plastic and steel. Capacitors may contain dielectrics that are hazardous to the environment, so they are often taken separately or require special disposal.
Frequently asked questions (FAQ)
Is it possible to get copper from a compressor using a magnet?
No, copper is not magnetic. A magnet can determine the presence of a steel core in the rotor and stator, but it will not “see” the copper winding itself. If the magnet sticks strongly to the parts inside, it is steel, not copper.
How much does a refrigerator compressor weigh without oil?
The weight of a dry compressor varies from 9 to 22 kg depending on the model. Oil makes up a small part of the weight (about 200-400 grams), so its absence has a slight effect on the overall weight, but is important for the scrap collection category.
Why is there less copper in modern refrigerators?
This is due to the rise in cost of raw materials and the development of technology. Manufacturers are optimizing designs, using thinner wire, new alloys and aluminum where this allows them to maintain operating efficiency but reduce costs.
Is it dangerous to open a compressor with an angle grinder at home?
Yes, it is dangerous. Pressure, oil and refrigerant vapor may remain inside. When cutting, sparks can ignite oil vapors. In addition, you risk damaging the tool on the hardened steel of the case.
Are compressors with welded tubes accepted?
Most collection points will accept compressors with tubes, but the price for them will be lower, since the buyer will have to spend time and resources to remove them. It is better to hand over the tubes separately as pure copper.