The question about the content of non-ferrous metals in household appliances often arises among those who plan to recycle an old unit or are trying to independently restore a broken one compressor. Many people mistakenly believe that the name “motor” implies the presence of a huge amount of pure copper, but the actual design of the electric motor is much more complex and interesting from the point of view of materials science.
In fact, the exact weight non-ferrous metal depends on the specific model, year of manufacture and manufacturer of the unit. Old Soviet refrigerators used motors with a large margin of safety and thick windings, while modern inverter models may contain less metal, but more complex alloys. Understanding these differences is critical to assessing the profitability of dismantling.
It is worth immediately noting that extracting copper for the sale of scrap is rarely economically justified for the average user when considering labor costs. However, for those who deal repair shop or disposing of equipment professionally, knowing the exact yield of metal allows you to competently plan warehouse stocks and waste removal logistics.
Compressor design and distribution of metals
Sealed compressor, which we are used to seeing on the back panel of the refrigerator, is a complex unit where the electric motor and pump part are enclosed in a single steel housing. Inside this “glass” there is a stator with a winding, a rotor and a shaft. It is the stator winding that is of interest as a source non-ferrous metal.
It is important to understand that there is not only copper inside. A significant part of the weight is made up of steel (body, core plates) and cast iron. The mass ratio is approximately the following: about 85-90% of the weight is occupied by ferrous metal and only 10-15% is accounted for by non-ferrous metals. This makes the process of manual cutting quite labor-intensive.
Modern manufacturers sometimes reduce the cost of construction by using aluminum instead of copper in windings, especially in low-power budget models. It is difficult to determine the winding material visually, but aluminum has less weight and a lower cost when delivered to a collection point collection point.
⚠️ Attention: When trying to open the compressor housing with a grinder or a hacksaw, there is a high risk of damaging the winding or getting injured from flying metal fragments. In the factory, the housing is welded in an inert gas environment, and its integrity is broken only with a special tool.
How much copper is in different models of refrigerators
Weight copper winding directly depends on the power of the electric motor, which, in turn, correlates with the volume of the fridge compartment. The larger the refrigerator, the more powerful the motor is needed to pump the refrigerant, and the thicker the wire is used in winding.
For clarity, it is worth considering the dependence of the volume of the chamber on the amount of metal. In large two-chamber models, the output non-ferrous metal can be two to three times higher than in compact single-chamber "tablets".
| Refrigerator type | Motor power (approx.) data-i="75">Weight of copper (gram) | Copper weight (grams) | Weight of ferrous metal (kg) |
|---|---|---|---|
| Small (single-chamber) | 100-120 W | 100-150 g | 4-5 kg |
| Medium (two-chamber) | 140-180 W | 180-250 g | 6-8 kg |
| Large (Side-by-Side) | 200-250 W | 300-400 g | 9-11 kg |
| Industrial | 300+ W | 500+ g | 12+ kg |
The data in the table are averaged, since winding design may differ. For example, motors of the SK (Soviet) series often contained more copper due to the use of high quality conductors, while Chinese counterparts may have a lower weight of useful metal.
Copper or aluminum: how to determine the winding material
Before starting disassembly, it is useful to determine which one non-ferrous metal is located inside. This will save time if it turns out that the engine is aluminum and converting it to copper is impossible. There are several simple ways to identify a material without deep chemical analysis.
The first method is visual and tactile. If there is access to the wire (for example, through a technological hole or during partial disassembly), pay attention to the color. Pure copper has a characteristic reddish-golden hue, while aluminum is silvery-white. However, the winding is often varnished, which makes inspection difficult.
The second method is checking with a magnet. Copper and aluminum themselves are not magnetic, but the stator core is made of electrical steel. If the magnet sticks to the winding wire, it is steel (which happens in very cheap models or indicates a diagnostic error). If it is not magnetic, it is either copper or aluminum.
Chemical test for aluminum
If you drop a solution of copper sulfate onto a stripped wire, a dark spot or reaction will appear on the aluminum after a few seconds, since aluminum is more active than copper. There will be no reaction on pure copper.>
The third sign is weight. An aluminum motor will be noticeably lighter than a copper counterpart of the same power. If you hold a motor from a large refrigerator in your hands, and it seems suspiciously light, most likely there is an aluminum winding inside aluminum winding.
Technology for extracting copper from the compressor
Extraction process non-ferrous metal requires special tools and compliance with safety regulations. Simple sawing of the body often leads to copper becoming contaminated with steel shavings, which reduces its cost when delivering non-ferrous metal to a collection point. First, you need to bleed off the refrigerant. Although the amount in old refrigerators is minimal, modern gases can be fire hazards or harmful to the environment. After this, the upper part of the body (“cap”) is cut off. collection point.
First you need to bleed off the refrigerant. Although the amount in old refrigerators is minimal, modern gases can be fire hazards or harmful to the environment. After this, the upper part of the body (“cap”) is cut off.
☑️ Tools for cutting
Next comes the most labor-intensive stage - knocking out the stator plate package from the housing or drilling out the rivets. Only after gaining access to the coils can you begin to remove them. Often the winding has to be burned or cut out, which requires caution.
⚠️ Attention: When burning the winding (burning varnish), caustic toxic fumes are released. This procedure can only be carried out outdoors or indoors with a powerful industrial hood. The use of a respirator is mandatory.
Economic feasibility and prices for scrap
Is the game worth the candle? If we consider the extraction of copper from one motor, the economic effect will be minimal. The cost of non-ferrous metal fluctuates (fluctuates), but even at high prices per kilogram, the output from one engine is pennies compared to the time spent.
However, if you have accumulated a batch of 10-20 old refrigerators, the situation changes. The total weight copper wire can be several kilograms, which is already noticeable when selling in bulk. In addition, the steel body also has value as black scrap.
There are categories of scrap on the market: “Copper mix”, “Lump copper”, “Winding”. A clean winding without varnish or burnt marks is more highly valued, but achieving such cleanliness in artisanal conditions is difficult. Most often they are sold as “Copper 2” or “Mix”, the price of which is lower.
Recycling of old compressors
Instead of scrapping, a serviceable or partially working one compressor can find a second life. DIYers often use them to create compressors for airbrushing, inflating tires, or even for vacuum pumps.
To do this, the engine is removed, cleaned of rust and equipped with a receiver (usually from an old gas cylinder or fire extinguisher). Such a system allows you to obtain a source of compressed air with a pressure of up to 6-8 atmospheres, which is sufficient for most domestic needs.
If the motor burns out, its stator can be used for rewinding. Knowing the number of turns and the diameter of the wire, you can restore the functionality of the unit. This is true for rare models where spare parts are no longer produced or are unreasonably expensive.
In conclusion, it is worth saying that the exact amount of copper in the motor is a variable value, depending on many factors. From Soviet reliability to modern material savings, each unit is unique. But in any case, competent disposal or reasonable reuse is preferable to simply throwing the equipment into a landfill.
Frequently asked questions (FAQ)
Is it possible to return the entire compressor without disassembling it?
Yes, most metal collection points accept entire compressors. However, in this case they will be assessed as “scrap of electric motors” or “ferrous scrap containing non-ferrous metal,” which is much cheaper than pure cut copper.
Is it dangerous to open the compressor due to freon residues?
Yes, it is dangerous. Even when the refrigerator is turned off, pressure remains in the system. When sawing the body, a sudden release of gas is possible, which can cause frostbite or fire (if a sparking tool is used). It is necessary to pre-drill a hole in the tubes or housing to relieve pressure.
How much does a typical refrigerator compressor weigh?
The weight of the assembled compressor (without the refrigerator housing) usually varies from 10 to 25 kilograms, depending on the power and dimensions. The motor “glass” itself weighs less, but together with the starting relay and capacitor, the weight increases.
Does it make sense to look for palladium in a compressor?
No, in ordinary household refrigerator compressors, precious metals like palladium or platinum are practically not used. The main contacts can be silvered, but their number is negligible for industrial production.