Question about content Precious and non-ferrous metals in household appliances often arises not only among inquisitive craftsmen, but also among those who are engaged in professional recycling or scrap sales. Refrigerator compressor is a sealed unit, inside which the electric motor winding, made mainly of copper, is hidden. It is this metal that constitutes the main value of the unit during recycling, but its exact weight depends on many factors, including the year of manufacture, motor power and manufacturer.
The average user rarely thinks about the internal filling while the equipment is working properly, but when it breaks down or is disposed of, this parameter becomes critical for assessing the profitability of restoration or scrap metal. Depending on the model, the amount of pure metal can vary from 300 grams to 1.5 kilograms, which makes a significant difference in the final cost. It is important to understand that sealed housing hides not only the winding, but also steel plates, oil and refrigerant, which must be taken into account in the calculations.
In this article we will analyze in detail the design of modern and old compressors so that you can accurately determine the potential yield of non-ferrous metal. You will find out which models are considered the most “rich” in copper, and which ones are dominated by aluminum or steel. The maximum copper yield (up to 1.2 kg) is observed in heavy Soviet compressors of the FK series and early Atlant models with a power of over 200 W. Analysis of these nuances will help to avoid mistakes when assessing scrap.
Compressor design and arrangement of copper elements
To understand where copper comes from, you need to look inside sealed casing. The compressor consists of two main parts: an electric motor that drives the piston group, and the compression mechanism itself. Copper is located exclusively in the stator of the electric motor, forming windings that create an electromagnetic field. The stator is made of thin plates of electrical steel, between which turns of wire are laid.
The amount of copper directly depends on the power of the engine and its energy efficiency. In older models, which did not use energy-saving technologies, the wire cross-section and number of turns were much larger, which made them heavier. Modern inverter compressors may contain less copper due to optimization of the magnetic circuit and the use of rare earth magnets, but this is not always the case - some high-efficiency motors remain very “copper-intensive”.
In addition to the stator winding, small amounts of copper can be found in connecting tubes and contact groups, however their weight is negligible compared to the main winding. The main volume is precisely the coils, filled with varnish and tightly packed in the grooves of the iron. When scrapping, it is important to take into account that it is almost impossible to extract copper without compromising the integrity of the stator, so the price is often formed based on the weight of the entire assembly with a coefficient for the metal content.
- 🔌 Stator winding: the main source of copper, constituting up to 90% of all non-ferrous metal in the assembly.
- ⚙️ Rotor: usually made of steel and copper (in the form of a short-circuited cage), but the proportion of copper here is minimal.
- 🔗 Contact group: the starting relay and terminals contain small copper elements.
⚠️ Attention: The internal pressure in the system and the presence of residual refrigerant make Cutting the body yourself is dangerous. Use only specialized tools and follow safety precautions when opening.
Why can’t you just weigh the compressor?
The weight of the compressor is not only made up of copper. Steel occupies up to 85-90% of the total mass of the unit. The oil inside also adds weight (about 300-500 grams), but has no value when delivered to non-ferrous metal. Therefore, the formula “compressor weight multiplied by 0.3” often gives an error.
Factors affecting the weight of copper winding
There is no single figure for all refrigerators, since manufacturers use different technologies and materials. The first and main factor is compressor power. The higher the power (measured in watts or horsepower), the thicker the wire and the longer it is. For example, compressors for large two-chamber refrigerators will contain more copper than the motors of compact single-chamber models.
The second important aspect is the year of production and country of origin. Soviet and early post-Soviet technology was famous for its “indestructibility” and excessive use of non-ferrous metals. At that time, saving resources was not a priority, so the windings were made with a large margin of safety. Modern Chinese and European models are often optimized for weight and cost, which can lead to the use of thinner wires or even partial replacement of copper with aluminum in some elements (although in high-quality motors the winding remains copper).
It is also worth considering the type of refrigerant and operating pressure. Compressors operating with R600a (isobutane)often have a smaller displacement and can be more compact than their R134a counterparts, which indirectly affects the size of the engine. However, the difference in the weight of copper here is not always linear, since the efficiency of modern motors is achieved due to the quality of steel and assembly precision, and not only due to the mass of the winding.
Comparative table: copper yield in popular models
For ease of assessment, we present averaged data obtained as a result of disassembling various types of compressors. These numbers will help you figure out what to expect from a particular unit. Please remember that the values may vary depending on the specific modification and year of manufacture.
| Compressor type / model | Total weight (kg) | Copper weight (grams) | Output percentage |
|---|---|---|---|
| Soviet (FK-140, HKU) | 10 - 12 | 900 - 1200 | ~10% |
| Atlant (series 80, 120) | 9 - 11 | 700 - 900 | ~8% |
| Donbass, Pozis, Biryusa | 8 - 10 | 600 - 800 | ~7-8% |
| Imported (Danfoss, Secop) | 7 - 9 | 400 - 600 | ~5-6% |
| Modern inverters (LG, Samsung) | 6 - 8 | 300 - 500 | ~4-5% |
As can be seen from the table, old Soviet models are real “storehouses” of non-ferrous metal. Their heavy body and massive engine contain record amounts of copper. Modern units have become lighter and more compact, which reduces the yield of useful raw materials. At the same time inverter models, despite the complexity of the design, they often lose in copper weight to classical asynchronous motors due to the use of powerful neodymium magnets in the rotor, which are not of interest for scrapping as non-ferrous metal.
⚠️ Attention: The data in the table are averaged. The actual metal yield depends on the condition of the winding (whether it is burnt out) and the specific series of the engine. Always allow for wear and tear.
Methods for determining copper content without opening
Opening a compressor to test a hypothesis is a labor-intensive and dangerous task. There are several indirect methods that allow you to approximately estimate the amount of copper without resorting to grinder or a hacksaw. The first method is weighing. Knowing the average percentage of copper content for a certain era and manufacturer, you can get an approximate value by multiplying the total weight by a coefficient.
The second method is visual inspection through technological holes. If you remove the plastic casing (plastic box) on the back wall of the refrigerator, you can sometimes see the color of the winding through the ventilation slots of the compressor itself. Bright red or orange tint indicates copper. If silver or white metal is visible, there is a high probability of using aluminum, which significantly reduces the value of the unit.
The third method is to analyze the documentation or markings. The compressor nameplate often indicates the power rating in watts (W) or horsepower (HP). By comparing this data with manufacturers' catalogs (for example, Secop or Embraco), you can find technical specifications, which sometimes indicate the weight of active materials, including the mass of the winding.
- ⚖️ Weighing: the simplest way. A heavy compressor (more than 10 kg) is almost guaranteed to contain a lot of copper.
- 👁️ Visual inspection: search for the characteristic copper luster through the housing holes.
- 📄 Marking: decoding model codes to find technical characteristics in networks.
Safe disassembly technology for metal extraction
If you are determined to extract copper yourself, you will need a serious tool and compliance with safety measures. The process begins by removing all external components: the protective casing, start relay and capacitor. Then you need to drain the oil, which can be aggressive and toxic. To do this, turn the compressor over and wait until the liquid has completely drained into the prepared container.
The most effective way to get to the winding is to mechanically open the housing. Using grinders with a metal disc allows you to carefully cut off the top of the “pot”. It is important not to damage the internal filling, especially if you plan to sell the copper as whole coils rather than shavings. After removing the cover, you will see a stator with wound coils.
Extracting copper from the stator is a labor-intensive process. The coils sit tightly in the grooves and are filled with varnish. They are cut out with a chisel or burned (which is not recommended due to the toxicity of the smoke). The cleanest result is obtained by carefully biting out one side of the coils and pulling the wire out from the other side. This allows you to get long pieces of wire, which are valued higher than a tangled mass.
☑️ Tools for disassembly
⚠️ Attention: When sawing the body, metal dust and sparks are formed. Work in a respirator and away from flammable objects. Remaining oil in the compressor may ignite upon contact with a spark.
Economic feasibility and disposal
Is the game worth the candle? To answer this question, you need to compare labor costs and the market value of scrap. At the moment, the price of insulated copper wire is lower than that of pure “burnt” or “shine”. If you spend several hours dismantling a single compressor to extract 500 grams of copper, the economic benefit tends to be zero unless you are recycling dozens of units.
In addition, you need to consider the cost of tools, electricity and equipment depreciation. For a private individual who has one old refrigerator, it is more profitable to hand over the entire compressor to a collection point for ferrous and non-ferrous metals, where the appraiser himself will determine the conversion factor. Professional recyclers use crushing complexes and separators, which allows them to process large volumes at minimal cost.
However, knowing what how many grams of copper is contained in the unit helps you avoid becoming a victim of deception when delivering scrap in bulk. If you are offered a price for “electric motor scrap” for a compressor that is 30% pure copper, this is a reason to bargain. Proper sorting and preliminary preparation (removing plastic, draining oil) can also increase the final cost of the batch.
Is it possible to determine the presence of copper with a magnet?
Yes, this is a simple method of primary diagnosis. Copper is not magnetic. If you bring a powerful neodymium magnet to the accessible parts of the winding through the ventilation holes and feel a strong attraction, this means that there is a lot of iron (steel stator plates) there. However, the wire itself cannot be checked with a magnet. Strong attraction of the compressor housing is normal, since it is made of steel. This method is more suitable for distinguishing aluminum from copper in cables, but in a compressor it is not very informative due to the dominance of steel.
Is it harmful to burn insulation from a copper wire?
It is strictly not recommended to burn insulation at home. When the varnish impregnated with the winding and the plastic insulation burn, toxic substances are released, including dioxins. In addition, burnt copper loses its properties, becomes brittle and is accepted by receivers at a lower price (“burnt” versus “shine”). It is better to hand over the wire in insulation or carefully strip it mechanically.
Is there gold or silver in the refrigerator compressor?
In the compressor (motor) itself there are no precious metals in quantities significant for mining. Relay contacts can be coated with silver, but its amount is measured in fractions of a gram. The main content of precious metals in refrigerators is concentrated in electronic control boards (if they are present in older models) or in the electronics itself, and not in the mechanical part of the compressor.