Which cable to use to bring electricity into an apartment: a complete guide

The issue of choosing a cable for introducing electricity into an apartment is one of the most critical when repairing or replacing wiring. An error at this stage may result in overheating of wiring, short circuit or even fires, and the correction will cost many times more than correct installation the first time. At the same time, the norms PUE (7th edition, 2026) and the requirements of energy supply organizations are constantly becoming more stringent - what was acceptable 5 years ago may not pass muster today.

Many people mistakenly believe that it is enough to take something “thicker and more expensive”, but in practice it is important core material, insulation type, cross-section, number of cores and even cable brand, approved in the technical specifications (TU) of your region. For example, in Moscow and St. Petersburg, energy supervision may prohibit the use PVS for input, while in the regions it is still sometimes used. Let's figure out which cable guaranteed to pass inspection in 2026, how to calculate the cross-section and avoid typical installation errors.

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1. Regulatory requirements for the input cable in 2026

From January 1, 2023, the updated Rules for electrical installations (PUE 7.1.34), which have tightened the requirements for input cables in residential premises. Main changes:

• 🔌 Ban on aluminum cables with a cross section of less than 16 mm² - even if they were previously installed. When replacing wiring, replacement with copper is required.
• 🔥 Increased requirements for fire resistance: The cable must be marked ng-LS (non-flammable, low smoke and gas emissions).
• 📏 Minimum section for single-phase input - 6 mm² (previously 4 mm² was allowed at a load of up to 7 kW).
• 🛡️ Mandatory protection from mechanical damage: corrugation, metal hose or hidden gasket in the wall.

In addition to the PUE, there are local regulations of energy supply organizations (for example, Mosenergosbyt or Lenenergo). They may have additional requirements:

• 📝 Technical conditions (TU) often specify specific brands of cables (for example, only VVGng-LS or NYM).
• 🔄 Ban on twists and soldering - only crimping with sleeves or terminal connectors like Wago 222.
• 🔌 Required availability input machine with a rating of no higher than 32 A for apartments (even if the cable cross-section allows more).

⚠️ Attention: If you are changing the input cable in an old house (for example, Khrushchev), energy inspection may require complete replacement of the riser from the driveway to the apartment - even if the problem is only in your area. This is due to the fact that aluminum risers from the 60s and 70s cannot withstand modern loads.

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2. Copper vs aluminum: what to choose for entering an apartment

Until the 2000s, aluminum cables (AVVG, Automatic reclosing) were actively used for inputs due to their low cost. Today they are used in apartments prohibited by PUE 7.1.34, with the exception of rare cases (for example, entry into a private house from a power line support). Why copper became mandatory:

Parameter	Copper cable	Aluminum cable
Conductivity	1.7 times higher	Lower, requires a larger section
Oxidation	Minimal, contacts last for decades	Fast, requires regular checking of connections
Flexibility	Easy to bend, convenient for installation	Breaks when bent repeatedly
Cost	2-3 times more expensive	Cheaper, but prohibited for apartments

The only case where aluminum can still be found is input from the power line support to the house (for example, SIP-4 16 mm²). But it is not allowed inside the apartment. If your house still has an aluminum riser, it necessarily needs to be replaced at the first repair - this is a safety issue.

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3. Optimal brands of cables for entry into the apartment

There are dozens of cable brands on the market, but only a few are suitable for entering an apartment in 2026. They match GOST 31996-2012 and have fire safety certificates. Let's look at the top 3 options:

• 🔹 VVGng-LS 3×6 (or 3×10) - the most common choice. Has three-layer insulation (PVC + non-flammable composition), suitable for hidden and open installation. Price: from 80 rub/m (6 mm²).
• 🔹 NYM 3×6 - German standard, similar VVGng, but with an additional layer of rubber insulation. It bends better, but is more expensive (from 120 rubles/m). Be sure to check the certificate - there are many fakes on the market.
• 🔹 VVGng-FRLS 3×6 — premium option with increased fire resistance (withstands open flame for 180 minutes). Required for luxury new buildings or objects with increased requirements (for example, apartments over 100 m²).

❌ What NOT to use:

• 🚫 PVS — flexible, but not intended for fixed wiring (only for carrying).
• 🚫 SHVVP - thin insulation, cannot withstand the load of the input cable.
• 🚫 KG — the cable is flexible, but has no markings ng-LS.

⚠️ Attention: If you buy a cable from a hardware store, ask certificate of conformity GOST R 53769-2010. In 2023, Rospotrebnadzor revealed that 30% of cable VVGng-LS on the market there are fakes with regular PVC, which burns and releases toxins.

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4. How to calculate the cross-section of the input cable

The cable cross-section depends on maximum load and network type (single-phase or three-phase). For most apartments, a single-phase input (220 V) is sufficient, but in new buildings or apartments with electric stoves, three-phase (380 V) may be required.

Calculation formula:

Cross section (mm²) = (Power of all devices × 1.2) / (Voltage × cosφ)

Where:

• 1.2 — safety factor.
• cosφ — power factor (for household appliances ≈ 0.95).

Example for a typical apartment (7 kW, 220 V):

(7000 × 1.2) / (220 × 0.95) ≈ 33.5 A → cross-section 6 mm² (withstands 40 A).

Load (kW)	Section (mm²), copper	Machine rating (A)
Up to 5.5	4	25
5.5–7.5	6	32
7.5–10	10	40
10–15 (three-phase input)	6 (per phase)	25 (per phase)

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5. Hidden or open gasket: which is better?

The way the input cable is laid affects its durability and safety. In 2026, the following rules apply:

• 🏠 Hidden gasket (in a groove or under plaster):
• ✅ Aesthetically pleasing, protected from damage.
• ❌ Requires corrugated or metal hose (PUE 7.1.38).
• ❌ Cannot be used VVGng without protection - only VVGng-LS or NYM.
• 🔌 Open gasket (in a cable channel or on clips):
• ✅Easy to replace or modify.
• ✅ Can be used VVGng without corrugation (but not VVG!).
• ❌ Spoils the interior, susceptible to mechanical damage.

⚠️ Attention: If the cable passes through fireproof structures (concrete, brick), laying without corrugation is allowed, but with gasket made of asbestos or mineralite (PUE 2.1.36). In wooden houses a metal corrugation or pipe is required - even for VVGng-LS.

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Check the requirements in the energy supervision specifications|Select a cable with a cross-sectional reserve of +20%|Lay a route without sharp corners (bending radius ≥ 5 cable diameters)|Use only certified connectors (not twists!)|Provide access to junction boxes-->

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6. Typical mistakes when installing the input cable

Even experienced electricians sometimes make mistakes that later lead to problems. Here are the most dangerous:

1. 🔌 Wrong section - for example, 4 mm² instead of 6 mm². Consequences: cable heating during peak loads (for example, turning on a heater and a washing machine at the same time).
2. 🔄 Direct connection of copper and aluminum without adapter terminals. Leads to electrochemical corrosion and loss of contact.
3. 🔥 No corrugation in combustible structures (for example, in a wooden house or plasterboard partitions).
4. 📏 Cable is too long with a reserve “for the future”, rolled into a bay. This creates inductive reactance and can cause false alarms of the RCD.
5. ⚡ Lack of grounding (PE conductor) or its incorrect connection (for example, to a heating battery).

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What happens if you neglect the corrugation in a wooden house?

During a short circuit, the temperature in the cable reaches 1500°C. Without metal protection (corrugations or pipes), wood ignites in 10–15 seconds. Even the cable VVGng-LS will not save - it will only slow down the spread of fire, but will not prevent fire.

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7. How to coordinate the replacement of the input cable with energy supervision

Replacing the input cable yourself without approval is administrative offense (Article 7.19 of the Code of Administrative Offenses of the Russian Federation, fine up to 2,000 rubles). To do everything legally, follow the algorithm:

1. 📄 Get technical specifications in an energy supply organization (for example, Mosenergosbyt). They will indicate:
• Acceptable cable brands.
• Section and number of cores.
• Requirements for machines (for example, S25 or S32).

🔍 Project verification (if required). For apartments up to 100 m², a sketch is usually sufficient.

🛠️ Installation a certified team (they must have a license to work up to 1000 V).

✅ Acceptance representative of energy supervision with drawing up a report.

⚠️ Attention: If you live in a home older than 1990, energy inspections may require replacement of the entire riser from the driveway to the apartment. This is due to the fact that old aluminum risers are not designed for modern loads. The cost of such a replacement is from 15,000 rubles. (shared between neighbors on the riser).

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FAQ: Frequently asked questions about the input cable to the apartment

❓ Can I use a 4 mm² cable for input if I have a 5 kW load?

Technically VVGng-LS 3×4 withstands 5.5 kW, but in 2026 energy supervision in most regions requires minimum 6 mm² - even for loads up to 7 kW. This is due to the provision for future appliances (for example, charging an electric car). If the specifications indicate 4 mm², you can use it, but it is better to take it with a reserve.

❓ What is the difference between VVGng and VVGng-LS?

VVGng — cable with non-flammable insulation (does not spread fire when laid alone). VVGng-LS - improved version with low smoke and gas emissions (LS - Low Smoke). To enter the apartment in 2026 the LS version is required, since it is safer in case of fire.

❓ Do I need to change the input cable if I am only replacing the internal wiring?

If the old input cable:

• ✅ Aluminum - be sure to replace to copper (PUE 7.1.34).
• ✅ With a cross-section of less than 6 mm² - it is better to replace it, as modern devices create a large load.
• ✅ Has damage to the insulation - replace without options.
• ❌ Copper, cross-section 6–10 mm², in good condition - you can leave it, but check the connections.

❓ Is it possible to lay the input cable along the floor under the screed?

Yes, but with mandatory conditions:

• 🛡️ The cable must be in metal corrugation or pipe (PUE 2.1.4).
• 📏 Laying depth - at least 30 mm from the surface of the screed.
• 🚫 Do not lay under doorways or in places where loads are possible (for example, under furniture).

It is better to avoid this option - in the event of flooding or repairs, there will be no access to the cable.

❓ Which brand of cable should I choose for three-phase input (380 V)?

For three-phase input (for example, into an apartment with an electric stove) the following are suitable:

• VVGng-LS 5×6 — 5 cores (3 phases + neutral + ground), cross-section 6 mm².
• NYM 5×6 - analogue with improved insulation.

Important: three-phase input requires three-pole machine (for example, S25) and uniform load distribution by phase (otherwise there will be “phase imbalance”).