Disassembling the compressor from an old refrigerator on copper: a detailed guide

Old Soviet refrigerators are a real storehouse of non-ferrous metals, and their compressors contain a significant amount of copper. If you have an unnecessary unit lying around ZIL, Biryusa or Minsk 70-90s, disassembling the compressor can bring not only material benefits, but also experience working with refrigeration equipment. However, the process requires care: inside the sealed case, refrigerant and oil are under pressure, and incorrect actions can lead to injury or freon leakage.

In this article you you will find step-by-step instructions with photo guidelines, a list of necessary tools and safety precautionsadapted for old-style compressors (type DXM-3, DXM-5, FGK). We will figure out how to drain the oil, bleed off residual freon, open the housing and remove the copper winding without damage. Special attention is paid to nuances that are not covered in general manuals - for example, working with stuck bolts or identifying compressors with aluminum parts (disassembling them is unprofitable!).

Before you begin, evaluate the feasibility: in some models (for example, Saratov-2 or Orsk) copper may be of low quality or in small quantities. In order not to waste time, in the first section we will tell you how to visually identify a “copper” compressor even before disassembly.

How to distinguish a compressor with copper winding: 5 visual signs

Not All old compressors are equally valuable. Here key markersby which you can determine that there is copper inside the case, and not aluminum or alloys:

• 🔍 Markings on the body: look for inscriptions DXM (for refrigerators ZIL, Minsk), FGK (for Biryusy) or PK (semi-hermetic compressors). data-i="79">Minsk AK or AD.
• 🎨 Case color: compressors with copper winding are usually painted dark gray or black. Light gray and silver cases are often aluminum.
• ⚖️ Weight: lift the compressor - copper models weigh 15-25 kg (due to heavy winding), aluminum ones are 30-40% lighter.
• 🔌 Power terminals: copper compressors have massive terminals, with thick bolts (∅8-10 mm). Aluminum ones have thin ones, often with plastic bushings.
• 📅 Year of manufacture of the refrigerator: compressors before 1985 are almost always copper, after 1990 - high probability of aluminum. Exception: industrial models (Whirlwind, Atlant older series).

If at least 3 out of 5 signs coincide, disassembly is justified. For accurate identification, you can use magnet test: copper is not magnetic, and neither is aluminum, but the compressor housing made of cast iron or steel will be attracted. If the magnet sticks to the housing, but not to the terminals, there is most likely copper inside.

Preparing for disassembly: tools and safety precautions

Disassembling a compressor is a dirty and potentially dangerous process. You will need:

• 🔧 Tools:
  • Pipe cutter or hacksaw for metal. (for cutting tubes).
  • Set of open-end wrenches (10-22 mm) and ratchet heads.
  • Slotted and Phillips screwdrivers (for removing the relay casing).
  • Pliers, wire cutters, hammer.
  • Drill with drill ∅3-4 mm (for draining oil).
• 🛡️ Protective equipment:
  • Respirator (when cutting the tubes there will be metal dust).
  • Safety glasses (required! oil may splash when opened).
  • Thick rubber gloves (the refrigerant will freeze the skin).
  • An apron or old clothes (oil from the compressor cannot be washed off).
• 🧹 Additionally:
  • Rags, cardboard or film for collecting oil.
  • Container for draining oil (a 5-liter canister is suitable).
  • WD-40 or kerosene (for unscrewing stuck bolts).
  • Marker and electrical tape (for marking pipes).

Important: the compressor must stand for at room temperature for at least 12 hours before disassembling. This is necessary so that the oil and refrigerant are evenly distributed inside the system. If you start work immediately after turning off the refrigerator, when cutting the tubes, oil under pressure may shoot out with a force of up to 5-7 atmospheres. hydraulic shock - oil under pressure will shoot out with a force of up to 5-7 atmospheres.

⚠️ Attention: even when the compressor is turned off, up to 300-500 grams of freon (R12 or R22) remain. These refrigerants are non-toxic, but if inhaled in large quantities they cause dizziness. Work in a ventilated room or outdoors! data-i="128">Attention

Step 1: Draining the oil and bleeding the refrigerant

First stage - removing workers liquids. Let's start with the oil:

1. Turn the compressor over upside down (terminals down). This is necessary so that the oil flows to the drain hole.

2. Locate it on the housing oil plug is a bolt with a hex head (usually ∅14-17 mm), located in the lower part. It can be hidden under a layer of dirt - clean the surface with a metal brush.

3. Place the container and carefully unscrew the plug with a key. - do not rush the process! Old-style compressors use up to 1.5 liters of mineral oil HF-12 or HF-22, which may contain refrigerant impurities.

4. If the oil does not flow, take a drill and drill a ∅3 mm hole next to the plug. This will help relieve the pressure.

Now let's bleed the refrigerant:

1. Find suction and discharge tubes (thin and thick copper tubes coming out of the compressor). The thick one is discharge (high pressure), the thin one is suction (low pressure).

2. Put on glasses and gloves! Take a pipe cutter and make a cut on thin tube (suction) - the residual will come out with a hiss. freon. Do not cut the thick tube first —there can be a residual pressure of up to 10 atmospheres!

3. Wait 10-15 minutes until the gas is completely released. Then you can. cut off the thick tube as well.

⚠️ Attention: if white smoke or frost appears when cutting the tubes, this means that liquid freon remains in the system. Immediately stop working and let the compressor warm up for 2-3 hours at room temperature!

Step 2: Removing the start relay and electrical part

Before opening the case, you need to remove starting relay and disconnect the windings. In old-style compressors, the relay is attached to the housing with two bolts (∅8 mm) and is covered with a plastic or metal casing.

Action algorithm:

1. Unscrew the bolts securing the relay and remove the casing. Under it you will see contact group with three terminals:

   • C (common) - common contact;
   • S (start) - starting winding;
   • R (run) - working winding.

Disconnect the wires by first photographing or marking their location. In old compressors, the wires can be soldered - in this case, use a soldering iron with a power of 60-100 W.

Under the contact group is thermal protection disk (if there is one). Carefully pry it with a screwdriver and remove it - it does not contain copper and is of no value.

After removing the relay, you will have access to top compressor cover, which is secured with 4-6 bolts. These bolts often stick - before unscrewing, water them generously WD-40 and let them sit for 10-15 minutes. If the bolt does not budge, try lightly tapping it with a hammer through a wooden spacer.

Step 3: Opening the housing and removing the rotor with winding

Now we move on to the most important stage - opening the sealed housing. In old-style compressors (DKhM-3, FGK-1.5), the housing consists of two parts, connected welded seam or bolts around the perimeter.

Instructions for opening:

1. If the case is bolted:

   • Unscrew all the bolts around the perimeter (usually 6-8 pieces, ∅10-12 mm).
   • Pry up the top cover with a screwdriver - it should budge.
   • If the cover does not budge, tap it in a circle with a rubber hammer.

If the body is welded:

• Take an angle grinder (grinder) with a cutting disc for metal.
• Carefully cut the seam around the perimeter, not going deeper than 2-3 mm.
• After cutting, pry the lid with a pry bar.

Inside you will see:

• Rotor with copper winding —this is the main value.
• Stator (some models also contain copper).
• Piston group —it can be sold as cast iron/steel scrap.
• Valves and springs —usually not of value.

To remove the rotor:

1. Unscrew the central bolt (∅14-17 mm) holding the rotor to the shaft.
2. Carefully pull out the rotor along with the winding. Be careful - the winding wires are fragile!
3. Unsolder or cut the winding leads from the terminals with wire cutters.

What to do if the rotor is stuck to the shaft?

If the rotor does not come off after unscrewing the bolt, try the following methods:

1. Heat the compressor housing around the shaft with a heat gun to 100-150°C (not higher, so as not to damage the winding!).

2. Tap the end of the shaft through the wooden spacer.

3. Use a bearing puller (if available).

4. As a last resort, cut the rotor with a grinder, but this will damage the winding and reduce its value.

Step 4: Cleaning and preparing copper for delivery

The removed winding will be covered with a layer of varnish, oil and dirt. In order for it to be accepted at the collection point, the copper must be cleaned until it shines. To do this:

1. Rinse the winding in kerosene or solvent (for example, 646). This will remove oil and varnish.

2. Use a wire brush or sandpaper (120-180 grit) to clean the wires from carbon deposits.

3. If the winding is heavily oxidized (green coating), use acetic acid:

   • Immerse the winding in 9% vinegar for 10-15 minutes.
   • Rub with a brush and rinse with water.
   • Dry in air or with a hairdryer.

Divide the copper by grade:

• M1 —pure copper without impurities (winding wires).
• M2 —copper with small inclusions (terminals, contacts).
• M3 — scrap with solder (if completely unsuccessful clear).

The price of copper at receiving points depends on purity and current market quotes. At the time of writing, the approximate prices are as follows:

Copper grade	Price per 1 kg (rub.)	Notes
M1 (pure)	700-900	Winding wires without insulation
M2 (with impurities)	500-700	Terminals, contacts with solder residues
M3 (scrap)	300-500	Winding with insulation or strong oxides

⚠️ Attention: some items receptionists do not accept copper from compressors without a certificate of demercurization (mercury removal). Although there is no mercury in refrigeration compressors, check this point in advance!

Common mistakes and how to avoid them

Even experienced craftsmen sometimes make mistakes during disassembly. Here are the most common:

• 🔥 An attempt to cut the pipes with an angle grinder without bleeding out the freon → risk of explosion or gas poisoning. Always bleed off the refrigerant through a thin tube first!
• 🔧 Using too much force when unscrewing the bolts → the thread is broken or the key is broken. Stuck bolts need to be soaked in WD-40 or kerosene.
• ⚡ Work without grounding tools → there is a risk of electric shock from the residual charge in the capacitors. Before starting work, short the compressor terminals with a piece of wire.
• 🧲 Confusion with copper grades → lowering the price upon delivery. Always separate pure copper (wires) from alloys (terminals).
• 🚫 Throwing away the piston group → loss of additional income. Cast iron pistons are accepted as scrap for 15-20 rubles/kg.

Another typical problem is incomplete removal of oil. If there is oil left in the winding, it may not be accepted at the collection point due to the risk of fire during remelting. To avoid this, after washing in kerosene, dry the winding in the oven at 100°C for 30 minutes.

FAQ: Answers to frequently asked questions

How much copper can be obtained from one compressor?

Old model compressors (DXM-3, FGK-1.5) contain:

• 1.2-1.8 kg of pure copper (rotor winding);
• 0.3-0.5 kg of copper with impurities (terminals, contacts);
• up to 0.2 kg of aluminum (relay housing, if it is aluminum).

Total: up to 2.5 kg of non-ferrous metal from one compressor. In industrial models (for example, Vikhr-PK) the amount of copper can reach 3-4 kg.

Is it possible to disassemble a compressor without a grinder?

Yes, if the housing is bolted. To do this:

1. Unscrew all the bolts around the perimeter.
2. Heat the case with a hair dryer (temperature 150-200°C) - this will help destroy the sealant.
3. Pry up the cover with a pry bar or a wide screwdriver.

If the body is welded, you can’t do without an angle grinder. An alternative is a hacksaw, but it will take 3-4 times longer.

What to do with the remaining oil from the compressor?

Oil from old compressors (HF-12, HF-22) you can:

• Use as wood lubricant (impregnation for wooden fences, sheds).
• Add to recycling for further disposal.
• Deliver as oil-containing waste (there are collection points paying 5-10 rubles/liter).

Do not pour oil on the ground - it is toxic to the soil!

Which compressor is more profitable to disassemble: from a refrigerator or an air conditioner?

Comparison of copper yield:

Parameter	Refrigerator (DXM-3)	Air conditioner (split system)
Copper mass, kg	1.2-1.8	0.8-1.2
Disassembly difficulty	Average	High (requires a freon pressure gauge)
Additional scrap	Cast iron, steel (piston group)	Aluminum (radiators)
Profitability	⭐⭐⭐⭐	⭐⭐

Conclusion: compressors from old-style refrigerators are more profitable in terms of cost and copper yield.

Is it possible to use copper from a compressor for homemade projects?

Yes, but with reservations:

• ✅ Suitable for:
  • Making inductor coils (after cleaning from varnish).
  • Soldering thick wires (section 4-6 mm²).
  • Decorative elements (for example, plates, if copper is polished).
• ❌ Not suitable for:
  • Powering sensitive electronics (copper may contain micro-inclusions of solder).
  • Making cookware (oil and refrigerant residues are toxic).
  • Stranded wires (copper is too hard).

Before use, check the copper with a multimeter resistance —it should not exceed 0.018 Ohm mm²/m (standard for pure copper).