Will your induction hob run on your existing circuit, or do you need Perilex and three-phase power? Short answer: it depends on the connected load printed on your hob. A hob up to around 3600 watts runs on a normal circuit of 16 amps (230V), because 16A x 230V is 3680 watts at most. Many modern induction hobs even have a power limiter that lets you set them low enough to fit on a single 16A circuit anyway. If your hob is above that limit, you need a heavier connection: a Perilex socket (5-pin) on two or three phases. From 7400 watts you almost always have to connect to 3 phases (400V).
In this article I explain exactly which connection goes with which load, what Perilex is, which cable size belongs to it, how the bridges on the terminal block work, and where the line lies between doing it yourself and calling an electrician. Down to earth, with real values, no guesswork.
First things first: check the rating plate
Before you unscrew anything: grab the manual or look at the rating plate on your hob. It shows the connected load in watts or kilowatts, and often a diagram of the connection options (1N, 2N or 3N). That number decides everything. Never rely on what is “usually” needed, because with induction the power varies quite a lot.
Roughly, you see three types:
- Small hob (2 zones), up to ~3600W: often fits on a normal circuit.
- Standard induction hob (4 zones), 7000 to 7400W: Perilex, 2 phases.
- Wide or heavy hob (e.g. 90 cm, or an induction range cooker), 7400W and up:
The connected load printed on the hob decides the connection you need. Perilex, 3 phases, 400V.
The connections in one table
Here is the core in a single table. The power figures come straight from the sum: amps x volts = watts.
| Connection | Voltage | Fuse | Max. power | For what |
|---|---|---|---|---|
| 1 phase (normal circuit) | 230V | 1x 16A | ~3680W | Small hob or hob with power limiting |
| 2 phases (cooker circuit) | 230V | 2x 16A | ~7360W | Most induction hobs |
| 3 phases (three-phase power) | 400V | 3x 16A | ~11,000W | Wide hobs, induction range cookers |
A domestic Perilex is rated as standard at 16A per phase. There are also heavier Perilex connections at 25A (mostly industrial), but in the home 16A per phase is the norm.
What exactly is a Perilex socket?
A Perilex is the stronger sibling of your normal socket. Where a normal socket has 3 contacts (live, neutral, earth), a Perilex is 5-pin: three phases (L1, L2, L3), a neutral (N) and an earth (PE). That lets far more power pass through without everything heating up.
You usually recognise the domestic version (16A) by the flat, horizontal earth pin. The industrial 25A version has a vertical earth pin and will not simply fit a domestic plug. Handy to know if you buy a loose Perilex plug: get the 16A version that matches your socket.
Note: with a new induction hob, the box often contains no ready-made lead with a Perilex plug. You have to buy a suitable connection lead yourself and fit it to the hob’s terminal block. That is exactly the point where things go wrong if you are not careful.
Why many induction hobs still run on 1x16A
This is the gap that many articles skip. A modern induction hob almost always has a power limiter (depending on the brand it is called Power Manager, power limit or power management, with Bosch, Siemens, Smeg, AEG and others). With it you set the maximum power of the whole hob in the manual’s menus, for example to 3500W.
What happens then? The hob never lets through more than that total power and distributes it cleverly across the zones that are on. Cook on one ring and the full power goes there. Switch on four rings and the hob shares the power out; not every zone reaches its maximum at the same time. In practice you rarely notice, because you almost never cook on four zones at once at the highest setting.
So: only have a normal circuit, but a hob with power limiting? Then you can often connect it to a single 16A circuit by setting the limiter to ~3600W. Always check the manual to see whether your specific model supports this and which value to set. If it cannot, or you are unsure, then a cooker circuit is the safe choice.
The bridges on the terminal block
Another underexposed bit. On the back of your hob sits a terminal block with terminals and a number of metal bridges (linking plates). Those bridges decide whether the hob runs on 1, 2 or 3 phases.
- On delivery the bridges are often in the single-phase position (all phase contacts linked together).
- If you connect to 2 or 3 phases, you have to remove or reposition certain bridges according to the diagram on the hob or in the manual.
- Set the bridges wrong and one phase can be overloaded, or the hob will not work.
Every brand has its own connection diagram (1N~ / 2N~ / 3N~). Follow that diagram exactly. This is the part where even handy DIYers often bring in the electrician, and that is wise.
Cable size: which cable for which fuse?
The cable has to be thick enough for the current running through it. Too thin means overheating and fire risk. In practice, these cross-sections are widely used in homes:
| Fuse | Cable size (practice) |
|---|---|
| 16A | 2.5 mm² per core |
| 25A | 6 mm² per core |
So for a Perilex cooker circuit at 16A per phase you use a 5-core cable of 2.5 mm² (often labelled 5G2.5). The exact choice, under IEC 60364 (BS 7671 in the UK), also depends on cable length, installation method and voltage drop. The basic rule of the standard is that the fuse must never let through more than the cable can safely handle. Not sure which size is right in your situation? Have an electrician work it out. Guessing here is exactly what you should not do.
Can I reuse my old single-phase cooker circuit?
Did you previously have an electric cooker or ceramic hob on a dedicated circuit? Then a suitable cable may already be in place. Two things to check:
- Is there a Perilex socket or a separate cooker circuit? Sometimes the cable is present but no Perilex is fitted yet.
- What is the size of the existing cable, and which fuse is it on? An old single-phase cooker circuit is sometimes connected to just one phase. For a hob that needs 2 or 3 phases, that is not enough.
You can often reuse an existing cooker circuit perfectly well, provided the size and fuse are right. But extending from 1 to more phases, or upgrading the connection, is work at the consumer unit and therefore electrician’s work.
Multi-phase connection: do you even have 3 phases in the house?
Many older homes still have a single-phase supply from the grid operator. A hob that needs 3 phases (400V) cannot simply be connected then, because those phases physically are not there.
You then have two options:
- Choose a hob you can connect to 1 or 2 phases (with power limiting or a 2-phase cooker circuit). This is usually the cheapest route.
- Have your supply upgraded to 3 phases through your grid operator. That is a separate application, costs money and time, and is only needed if you really want a heavy hob or range cooker.
So know before you buy a hob what your consumer unit can handle. That saves you an expensive surprise.
Step by step: connecting an induction hob
For the situation where a suitable Perilex socket or cooker circuit is already in place and you fit the lead yourself:
- Read the rating plate and the manual. Determine the connected load and the correct diagram (1N, 2N or 3N).
- Switch off the power. Turn off the relevant circuit and the main switch. Check with a voltage tester that there really is no voltage left.
- Set the bridges correctly. Follow the connection diagram on the hob for your number of phases.
- Connect the cores to the terminal block: phases, neutral and earth to the right terminals. Tighten the terminals firmly.
- Fit the Perilex plug to the other end of the lead, if it is not already on. Phases, neutral and earth to the right pins.
- Set the power limiter if needed, if you are connecting to a single 16A circuit.
- Check everything once more, plug it in, switch the power on and test each zone.
Get to step 3, 4 or 5 and start to doubt? Stop and call a registered electrician. There is no shame in it.
DIY or electrician: where is the line?
Honest talk. Work at the consumer unit (adding a new circuit or Perilex connection, upgrading the supply) you leave to a registered electrician. There is high current involved, an RCD of 30mA has to be fitted, and a mistake is life-threatening or a fire hazard.
What a handy DIYer can often do themselves: fit a lead with a Perilex plug to the hob and plug the hob into an existing, correct Perilex socket, provided the power is off and you work to the diagram. But know your limit.
And think of your insurance. If a fire starts because of an incompetently installed electrical connection, your insurer can refuse the claim and you are liable. The saving from doing it yourself then does not outweigh the risk. When in doubt: outsource.
What does it cost? For installing a new circuit or Perilex connection, reckon on a range of roughly 100 to 250 euros in electrician’s fees, depending on your consumer unit and the distance. If your supply has to be upgraded to 3 phases via the grid operator, separate costs come on top that can run up considerably. Always ask for a quote up front.
Frequently asked questions
Can I connect an induction hob to a normal socket?
Only if the connected load stays under around 3600W, or if you set the hob’s power limiter so it stays within 16A (3680W). Larger hobs need Perilex.
What is the difference between connecting to 230V and 400V?
230V is one phase (or two phases with a cooker circuit). 400V is three phases together, that is three-phase power, letting you deliver far more power. From 7400W, 3 phases (400V) are almost always required.
Do I always need Perilex for induction?
No. A small hob or a hob with power limiting runs on a normal 16A circuit. Most standard 4-zone hobs do need Perilex, though, because they sit around 7000 to 7400W.
Is a lead with a Perilex plug included with my hob?
Usually not. You often have to buy and fit the connection lead and the Perilex plug yourself. Choose the 16A domestic version that matches your socket.
What are those bridges on the terminal block?
Metal plates that link the phase contacts. They decide whether the hob runs on 1, 2 or 3 phases. You reposition or remove them according to the diagram on the hob. The wrong way round means overload or a hob that will not work.
Am I allowed to connect it myself for my insurance?
Fitting the plug and plugging into an existing Perilex socket is often something you may do yourself. Work at the consumer unit you leave to a registered electrician. In case of fire due to incompetent work, your insurer can refuse to pay out.
From gas to induction: think of the bigger picture
Connecting an induction hob is often part of a bigger step: from gas to fully electric cooking. That is not just a matter of a plug, but of dealing more smartly with energy across your whole home. Want to know how to make that switch as cheaply as possible and where else you can save on your energy bill? Then have a look at Energie Verpulveraar. There we help you electrify your home step by step, without surprises.
Cooking on induction is wonderfully fast and economical. Just make sure the connection is right, because that is where safe cooking pleasure begins.