Short answer
Three-phase power is 400 volts across three phases, and you need it for heavy equipment: a workshop machine, a large cooking installation, a compressor or a 22 kW EV charger. In a home with a three-phase connection, installing a power circuit is work in the meter cupboard. If you only have single-phase, the connection must first be upgraded, and that takes weeks.
Who this article is for Anyone getting a heavy machine or installation. The installation is work for an installer; I do the application together with you.
What three-phase power is
With an ordinary circuit you have a live and a neutral: 230 volts. With three-phase power you use three phases at once, giving you 400 volts between the phases. For the same power that means less current per conductor, and heavy motors are built for that.
When you need it
- a machine with a 400 volt motor: saw, lathe, compressor
- a 22 kW EV charger
- a large cooking installation or a commercial kitchen
- a heavier type of heat pump
- sometimes a sauna or a large water heater
If in doubt, look at the rating plate of the appliance. If it says 3N or 400 V, it is three-phase.
Do you already have three-phase
You can see that in the meter cupboard: with three-phase there are three fuses or a three-pole main switch, and the cable from the street has more conductors. If in doubt, send a photo of the cupboard and I will see it straight away.
This is the first question, because the difference is half a day or half a season.
If you have three-phase, installing a power circuit is half a day to a day's work: a circuit in the consumer unit, a cable to the location and a CEE socket or a fixed connection.
If you only have single-phase, the connection must first be upgraded by the grid operator. That is an application with a waiting time of weeks to months, and sometimes digging in the pavement. See upgrading the connection.
The socket
For separate machines you use a CEE socket, recognisable by its red colour. The common versions:
| Version | What for |
|---|---|
| 16 amps, 5-pin | most workshop machines |
| 32 amps, 5-pin | heavier machines, charging point |
| 63 amps | commercial use, generators |
Permanently connected equipment does not get a plug but a visible isolator switch, so something can be switched off during maintenance.
What it costs
The work in the meter cupboard and the cable account for most of it. The price for installing three-phase power is on the prices page; what comes on top in your case depends on the distance and the position of the socket.
If an upgrade is needed, the grid operator's costs come on top. I never pass those on: that invoice comes directly to you.
From my own work
In a workshop in Geleen a pillar drill with a 400 volt motor was coming in. The home had three-phase, so nothing needed to be applied for. A power circuit with a CEE socket in the workshop, and half a day later the machine was running. If there had only been single-phase, the same small job would have waited six weeks for the grid operator.
When to call an electrician
- A machine or appliance with a 400 volt connection is coming
- You do not know whether your home has three-phase
- A CEE socket is needed in the garage or workshop
I first look in the meter cupboard at what you have, because that decides whether it will be half a day or six weeks. Request a quote.
Frequently asked questions
How can I tell whether I have three-phase power?
In the meter cupboard: with three-phase there are three fuses or a three-pole main switch. A photo of the cupboard is enough to judge it.
How long does upgrading to three-phase take?
The application to the grid operator usually takes weeks to months, depending on how busy they are and whether digging is needed.
Can I run a 400 volt machine on 230 volts?
Sometimes a motor can be switched over, but usually not, and then it gives less power or causes damage. Check the machine's manual.
Further reading
What does an electrician cost in 2026? Hourly rate and call-out charge explained
Hourly rate, call-out charge, material margin and VAT, without beating about the bush. Including what I charge myself and why a fixed call-out charge is fairer.
Electrics in the bathroom: what is allowed where
The bathroom is divided into zones. For each zone the standard sets what may be installed and how well it must be protected.
Electrics in a new kitchen: which circuits and where
A modern kitchen easily has four to six circuits. Induction almost always needs its own power circuit.
Questions and comments
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