The question of how much copper is contained in a refrigerator compressor often arises among those who recycle old household appliances or professionally collect non-ferrous metals. Many people mistakenly believe that the entire heavy electric motor consists of pure non-ferrous metal, which makes its delivery extremely profitable. However, the reality is that copper makes up only part of the internal volume, and the rest is made up of steel, aluminum and various technical oils.
The exact weight depends on the model, year of manufacture and manufacturer compressor. Soviet units, known for their massiveness, contain significantly more metal than modern lightweight models. Understanding the design of the motor allows you to assess in advance the economic feasibility of disassembly and understand exactly what volume of non-ferrous metal can be extracted in the end.
In this article we will analyze in detail the design of sealed blocks, provide average data on scrap yield and explain why the numbers on the forums can vary greatly. You will learn how to correctly identify the type of winding and whether it is worth spending time on mechanically removing the wire or whether it is easier to hand over the entire assembly.
Compressor design and distribution of metals
To understand where copper comes from, you need to look inside sealed casing. A refrigerator compressor is a complex mechanical device where electrical energy is converted into the movement of pistons. The main mass here is occupied steel: housing, shaft, piston group and electric motor plates. Copper is used exclusively to create an electromagnetic field in the stator.
Inside there are two main coils: starting and working windings. They are wound from copper wire. However, depending on the price category of the refrigerator and the year of its manufacture, manufacturers may use aluminum wire lacquer coating, which is visually difficult to distinguish from copper without inspection. The weight of the stator also includes packages of transformer steel, which constitute up to 70% of the mass of the electric motor itself.
⚠️ Attention: Inside the compressor there is technical oil, which may contain wear products and chemical impurities. When opening the case, be careful not to pour the liquid into the soil or sewer.
The difference in weight between copper and aluminum windings is significant, since the density of copper is almost three times higher. If you plan to hand over scrap, preliminary diagnosis of the type of metal will help avoid unpleasant surprises upon acceptance. Often, unscrupulous assemblers try to pass off aluminum as copper, but experienced inspectors can easily determine this by weight or magnet (although the magnet does not act on non-ferrous metal, it shows the steel in the structure).
Average weight of copper in different models of refrigerators
The amount of non-ferrous metal directly correlates with the dimensions of the refrigeration unit and the power of its engine. Small single-chamber models of the last century were equipped with less powerful motors, but with more “honest” winding. Modern two-chamber units with the No Frost system require more efficient compressors, however, optimization of production has led to a reduction in wire cross-section and sometimes replacement of materials.
If we consider the average indicators, then in a standard household compressor the yield of pure copper ranges from 100 to 250 grams. This seems like a small amount, but when processing dozens of pieces of equipment, the amount becomes noticeable. It is important to consider that scrap yield is never 100% due to the impossibility of completely clearing the wire of varnish and solder.
Below is a table showing the dependence of the amount of copper on the type and size of the compressor. The data is approximate, since technologies change, and manufacturers do not always indicate the exact weight of the windings in the specifications.
| Compressor type | Approximate compressor weight | Stator weight (with steel) | Copper yield (gram) |
|---|---|---|---|
| Low-power (single-chamber) | 9 - 11 kg | 2.5 - 3.0 kg | 80 - 120 g |
| Medium power (classic) | 11 - 14 kg | 3.5 - 4.5 kg | 130 - 190 g |
| Powerful (No Frost, large) | 14 - 17 kg | 4.5 - 5.5 kg | 180 - 260 g |
| Industrial/Soviet | 18 - 25 kg | 6.0 - 8.0 kg | 300 - 450 g |
As can be seen from the table, even in the heaviest household version, the copper content rarely exceeds half a kilogram. The bulk is made up of ferrous metal, which also has value, but is much cheaper. Therefore, when collecting equipment, it is important to take into account logistics: carrying one compressor for the sake of 200 grams of copper is not economically feasible.
Copper or aluminum: how to determine the winding material
One of the most critical moments for a scrap appraiser is the identification of the winding metal. Visually, especially if the wire is hidden inside the stator slots and is visible only at the point where the contacts exit, it can be difficult to distinguish them. Aluminum windings are often coated with copper-colored paint or alloys that imitate yellow metal are used. However, there are proven diagnostic methods.
The easiest way is weight assessment. Copper wire is much heavier. If you hold the removed stator in your hands and it seems suspiciously light for its size, most likely the inside aluminium. You can also use a magnet: although neither copper nor aluminum is magnetic, the force of attraction to the steel core through the winding layer can indirectly indicate the thickness of the insulation and the winding density, but this is a method for experts.
- 🔍 Wire cut: if you have access to the end, make a small cut. Copper has a characteristic pinkish-red color over the entire cross-sectional area, aluminum is silver-gray.
- 🔥 Thermal sample: when heated, aluminum quickly oxidizes and turns white, copper turns black, but retains a metallic luster after stripping.
- ⚖️ Density: a piece of copper weighing 10 grams will be visually three times smaller than a piece of aluminum of the same weight.
It is worth noting that the presence of aluminum winding does not mean the low quality of the refrigerator itself. Many modern manufacturers successfully use aluminum, increasing the cross-section of the wire to compensate for its lower electrical conductivity. However, for a scrap metal collection point, these are two different goods with different prices.
⚠️ Warning: Do not attempt to identify metal by drilling into a running or plugged-in compressor. This is deadly and can lead to a short circuit.
Technology for extracting copper from the stator
The process of extracting copper from a compressor requires a certain set of tools and physical strength. It is not possible to simply shake out the winding, since it is tightly pressed into the stator slots and filled with varnish. There are two main methods: mechanical (knocking out) and thermal (burning out).
The mechanical method involves the use of a chisel, hammer and grinder. First, the frontal parts of the winding are cut off on one side of the stator. Then the stator is placed on a hard surface and the remaining wires are knocked out from the opposite side. This method allows you to keep the metal clean, but requires a lot of time and effort.
☑️ Tools for disassembly
The thermal method involves heating the stator to high temperatures to burn off the varnish and insulation. After this, the wire becomes soft and can be easily removed. However, this method has a serious drawback: when the varnish and insulation burn, the copper is covered with an oxide film, which reduces its grade upon delivery. In addition, the process is accompanied by the release of acrid smoke.
Although it may have been safe in older models, modern freons can be flammable or toxic. Before cutting the case, it is necessary to drill holes in the copper tubes and allow the gas to completely escape in a well-ventilated area.
Economic feasibility of disassembly
Is the game worth the candle? To answer this question, you need to carry out simple mathematical calculations. Let’s say the price of copper at the receiving point is approximately 600 rubles per kg, and ferrous metal - 20 rubles per kg. From one compressor weighing 12 kg we will get about 0.2 kg of copper (120 rubles) and 11.8 kg of steel (236 rubles). Total: 356 rubles.
If you hand over the entire compressor as scrap (which many points do without requiring disassembly), you will receive about 240 rubles. A difference of 116 rubles may seem significant if you have 100 compressors. But if you spend 30 minutes disassembling one motor, your hourly rate will be extremely low.
Hidden costs of disassembly
Don't forget to take into account the cost of grinder wheels, electricity, tool depreciation and, most importantly, your time. It is often more profitable to hand over the entire unit.
The most rational approach is to accumulate a large amount of equipment. It makes sense to disassemble one compressor at a time only for the sake of training or if you already have free time and equipment. For professionals with cutting machines and large volumes, this becomes a full-fledged business process.
The influence of the year of manufacture on the content of precious metals
Although the main interest is copper, compressors can also contain precious metals, albeit in microscopic quantities. Relay contacts and some solders and platings may contain silver, palladium, or gold. In Soviet technology (before 1990), the content of non-ferrous and precious metals was higher due to other production standards.
Modern compressors, especially inverter ones, have more complex electronic components, but the motor itself has become lighter and “more economical” in resource consumption. Manufacturers strive to minimize the weight of the product to reduce transportation costs and the cost of delivery to the end consumer.
- 📅 Before 1990: High copper content, thick windings, often brass elements.
- 📅 1990-2000: Transitional period, both copper and aluminum are found, weight reduction.
- 📅 2000+ years: Optimization, use of composites, aluminum and rare alloys.
If you find an old Soviet refrigerator, the likelihood of finding a high-quality heavy compressor with a high copper yield is very high. Such models are valued by assemblers higher than modern Chinese or European analogues of a similar size.
Frequently asked questions (FAQ)
Is it possible to hand over the entire compressor, without disassembling it?
Yes, most scrap metal collection points accept entire compressors. However, they will classify it as an “electric motor” or “ferrous scrap containing non-ferrous metal” and will pay at a reduced price, since they assume independent processing.
How much does an empty compressor housing weigh after removing the copper?
After removing the stator, piston group and oil, the empty sealed casing weighs little. The bulk of the weight (about 80-90%) is lost when the internal components are removed. All that remains is a thin-walled steel can.
Is it harmful to burn insulation from a copper wire?
Yes, it is harmful. When varnish, enamel and plastic insulators burn, toxic substances are released. This can only be done in special ovens with a smoke filtration system, and not on an open fire in the yard.
Is there gold in the refrigerator compressor?
There is no gold in the electric motor itself. It may be contained in microscopic quantities in the contacts of the starting relay or electronic control unit (if it is built-in), but its quantity is so small that refining will not cover the cost of reagents.
What to do with oil from a compressor?
Technical oil is a waste of hazard class 3-4. It should not be poured into the ground or sewer. Take it along with the work to special collection points or service stations.