Connecting a hob is a task that requires not only accuracy, but also precise calculations. Error in choice wire cross-section may cause cable overheating, short circuit or even fire. It is especially important to consider that modern induction and electric stoves consume from 3 to 10 kW - this is several times more than that of a regular outlet.

Many car owners, when setting up a garage or workshop with a kitchen area, are faced with the need to connect the hob to a 220V or 380V network. But how not to make a mistake with the wire? Do I need to draw a separate line from the shield? And why is copper cable always preferable to aluminum? The answers are in this guide, with calculations, tables and warnings from professional electricians.

We will analyze not only the theory, but also practical nuances: from choosing a machine to the connection features in the garage, where the electrical network is often weaker than in the apartment. And you will also find out what errors most often made during installation - and how to avoid them.

1. Why is the wire cross-section critical for a hob?

A hob is not a refrigerator or a microwave. Her peak power can reach 7–10 kW, which is comparable to the simultaneous operation of several household appliances. If the wire is too thin, it will begin to heat up and the insulation will melt. Consequences:

  • 🔥 Fire due to overheating of the cable in the wall or junction box.
  • ⚡ Short circuitif the insulation melts and exposes the conductors.
  • 💡 Voltage drop - the panel will work unstable or turn off.

At the same time aluminum wires (which are still found in old garages) heat up more than copper ones at the same load. Therefore, for hobs they use copper cable only with the correct section.

Key rule: wire cross-section must withstand maximum current, which the panel consumes, with a margin of at least 20%. For example, if the panel takes 32 A, the cable must be rated for 38–40 A (taking into account possible voltage surges).

📊 Which hob are you planning to connect?
Induction (power 7+ kW)
Electric (3–5 kW)
Gas with electric ignition (up to 1 kW)
I haven't decided yet

2. How to calculate wire cross-section: formulas and tables

To calculate the cable cross-section you need to know:

  1. Hob power (P, in watts).
  2. Mains voltage (U: 220V for single-phase, 380V for three-phase).
  3. Wire material (copper or aluminum).

Formula for finding maximum current (I): 

I = P / U

For example, for a panel with a power 7 kW (7000 W) on a 220V network: 

I = 7000 / 220 ≈ 31.8 A

Now, using the table, we select the cross-section of the copper wire that can withstand not less than 32 A:

Wire cross-section, mm² Max. current for copper, A (hidden wiring) Max. power at 220V, kW Max. power at 380V, kW
2.5194.211.0
4.0275.915.7
6.0347.520.1
10.05011.029.0

The table shows that it is suitable for 7 kW cable 6 mm² (withstands up to 34 A). But if the panel is more powerful (for example, Bosch PUE611BF1E at 7.4 kW), it’s better to take 10 mm² for stock.

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If the hob is connected in a garage, where voltage fluctuations are possible, take the cross-section one step higher. For example, for 7 kW - not 6 mm², but 10 mm².

Features of three-phase connection (380V)

In workshops or garages, a three-phase network is often used. Here the current is distributed over three wires, so the cross-section can be taken smaller. For example, for the same 7 kW panel: 

I = 7000 / (380 × √3) ≈ 10.9 A

Enough cable 2.5 mm² (withstands 19 A). But! In a three-phase network A 4-wire cable is required (3 phases + neutral) or 5-wire (3 phases + neutral + earth).

3. Which cable to choose: brand and design

Not all copper cables are created equal for the hob. Optimal options:

  • 🔌 VVGng-LS 3×6 - non-flammable, low smoke emission. Suitable for hidden wiring in a wall or cable duct.
  • 🔌 NYM 3×6 — imported analogue of VVG, with additional insulation. Convenient for installation in the garage.
  • 🔌 PVS 3×6 - flexible multi-core cable. Used to connect the panel to an outlet (not for fixed wiring!).

It is prohibited to use:

  • ❌ Aluminum wires (for example, AVVG).
  • ❌ Single insulated cables (e.g. PUNP).
  • ❌ Wires with a cross-section of less than 4 mm² for a single-phase network.
⚠️ Attention: If your garage already has aluminum cable installed, do not connect the hob directly to it. It's better to run a new copper line from the shield or use terminal blocks to connect aluminum to copper (but this is a temporary solution!).

Check the power of the hob in the passport|Choose copper, not aluminum|Consider the type of network: 220V or 380V|Buy a cable with a reserve cross-section (1–2 mm² more than the calculated one)|For hidden wiring, take non-flammable brands (VVGng-LS, NYM)-->

4. Connecting the hob: diagram and machines

Even a correctly selected cable does not guarantee safety if it is chosen incorrectly. circuit breaker and RCD. Here's what to consider:

For single-phase network (220V):

  • 🔋 Automatic: at 32 A for panels up to 7 kW, at 40 A for 7–10 kW.
  • 🔌 RCD: at 40 A with a leakage current of 30 mA (required!).
  • 🔌 Socket: special power supply for 32–40 A (for example, Legrand 416071).

For three-phase network (380V):

  • 🔋 Automatic: 16 A (up to 10 kW) or 25 A (10–15 kW).
  • 🔌 RCD: 25 A, 30 mA.
  • 🔌 Socket: three-phase 16–25 A (for example, ABB 416RS6).
⚠️ Attention: Never connect the hob through a regular 16 A socket! Even if the panel is low-power (3–4 kW), the socket contacts are not designed for long-term load and will heat up.

Connection diagram (for single-phase network):

  1. We lay the cable from the shield VVGng-LS 3×6 to the panel installation location.
  2. We install a 32 A automatic circuit breaker and a 40 A/30 mA RCD.
  3. We connect the power outlet or terminal block (if the panel does not have a plug).
  4. We connect phase (L), neutral (N) and ground (PE) according to the diagram in the instructions for the panel.
What happens if you connect a panel without an RCD?

Without an RCD (residual current device), if the insulation on the panel body breaks down or there is a current leak, you risk getting an electric shock. For example, if a phase wire touches a metal case and you touch the panel, current will flow through your body. The RCD will turn off the power in a split second, saving lives.

5. Typical mistakes when choosing and installing wires

Even experienced electricians make mistakes sometimes. Here are the most common mistakes:

1. Saving on cross-section

“Why not take a 4 mm² cable instead of a 6 mm² cable? What if he can stand it? - Many people think so. But a 4 mm² wire with a load of 7 kW will heat up to 60–70°C, which reduces the service life of the insulation by 2–3 times.

2. Use of aluminum

Aluminum wires are common in older garages. They absolutely cannot be used for hobs, because:

  • Aluminum oxidizes and loses conductivity.
  • When heated, aluminum “flows,” which worsens the contact in the terminals.
  • According to the PUE (clause 7.1.34), for new electrical wiring in residential and domestic premises aluminum is prohibited.

3. Incorrect wire connection

Twists, even well insulated, are a ticking time bomb. To connect cables use:

  • 🔧 Terminal blocks (for example, Wago 222).
  • 🔧 Crimping with sleeves (for multi-core wires).
  • 🔧 Welding or soldering (the most reliable method).

4. Ignoring the RCD

Many people think that an automatic rifle is enough. But the machine only protects against short circuit and overload, and the RCD protects against leakage current, which can kill a person.

5. Cable laying without protection

If the wire runs along a flammable surface (for example, a wooden wall in a garage), it must be placed in:

  • 🔥 Metalsleeve.
  • 🔥 Non-flammable PVC corrugation.
  • 🔥 Cable channel with fire safety certificate.
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The most dangerous mistake is connecting the hob through an extension cord. Even a “powerful” 16 A extension cord is not designed for a continuous load of 7 kW and can catch fire.

6. Features of connection in a garage or workshop

In a garage or auto repair shop, connecting a hob has nuances:

  • 🚗 Weak network: In garages, you often find old wiring that is not designed for high loads. Before connecting the panel, check whether the input cable and the circuit breaker in the panel can withstand it.
  • 🚗 Humidity and dust: Use sockets and circuit breakers with protection class IP44 (dust- and moisture-proof).
  • 🚗 Lack of grounding: Old garages often do not have a ground loop. In this case necessarily install an RCD with a leakage current of 10 mA (more sensitive than the usual 30 mA).

If the garage has a three-phase network (380V), you can save on the cable cross-section (as calculated above). But remember:

  • Three-phase panels require uniform load distribution by phases. If one phase is overloaded, the machine may trigger falsely.
  • For three-phase connection you need special cable with 4–5 cores (3 phases + neutral + earth).
⚠️ Attention: If there is a homemade electrical panel or circuit breakers from an unknown manufacturer in the garage, before connecting the panel necessarily replace them with certified ones (for example, ABB S200 or Legrand TX3). Cheap Chinese machines may not work if overloaded!

7. How to check whether the section is selected correctly

If you have already connected the panel, but are in doubt about the correct cable choice, do the following:

  1. Turn all burners on maximum power.
  2. After 10–15 minutes, check the cable temperature in several places (by hand or pyrometer).
  3. If the wire warm (up to 40°C) - everything is fine.
  4. If hot (above 50°C) or smells like melted insulation - turn off the panel immediately and replace the cable with a thicker one.

Also pay attention to:

  • 🔌 Automatic: if it periodically knocks out for no apparent reason, the cable cross-section may be insufficient.
  • 🔌 Socket: If it gets hot or melts, the problem is in the contacts or the wire is too thin.
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For an accurate check, use current clamps (for example, Fluke 323). Measure the actual load current and compare it to the maximum allowed for your cable.

FAQ: Frequently asked questions about the hob cable

Is it possible to connect a 3.5 kW hob through a regular outlet?

Technically possible, but highly not recommended. A regular 16A outlet is rated for maximum power 3.5 kW, but only under short-term load. If the panel is left running for hours, the outlet and wiring will overheat. It is better to extend a separate line with a 4 mm² cable and a 25 A circuit breaker.

What wire is needed for a 7.2 kW induction panel?

For a single-phase network (220V) - copper cable 6 mm² (for example, VVGng-LS 3×6), automatic 32 A and RCD 40 A/30 mA. For a three-phase network (380V) - a 4 mm² cable (5 cores), a 16 A circuit breaker and a 25 A/30 mA RCD.

What to do if there is aluminum wiring in the garage?

The best option is to replace it with copper from the shield to the panel. If this is not possible:

  1. Use terminal blocks for connecting aluminum to copper (for example, Wago 2273 with pasta).
  2. Take a cable with a spare cross-section (for example, 10 mm² instead of 6 mm²).
  3. Install an RCD with leakage current 10 mA (for extra protection).

But remember: this connection is a temporary solution. Aluminum will oxidize in any case, and contact will deteriorate over time.

Do I need to ground my garage cooktop?

Yes, definitely! Without grounding, if the insulation breaks down on the housing, the panel will become deadly. If your garage does not have a ground loop:

  • Do local grounding (a metal pin driven into the ground next to the garage).
  • Use RCD 10 mA - it will work even with minimal leakage.

Do not connect the ground to heating or water pipes - this is dangerous!

Is it possible to use the PVS wire for a permanent connection?

No. PVS - this is a flexible connecting wire, it is designed to connect devices to an outlet (for example, extension cords). For stationary wiring in a wall or cable duct you need rigid cable (VVGng-LS or NYM). Over time, PVA can break at the bending points, which will lead to a short circuit.