Three-Phase Power at Home: Do You Need It?

A single-phase supply has one live conductor and a neutral, delivering 230V. Most homes have a main fuse of 60A, 80A or 100A, which limits how much power the house can draw at once – roughly 14kW, 18kW or 23kW.

A three-phase supply has three live conductors, each at 230V to neutral and 400V between phases. It can deliver around three times the power of a single phase with the same fuse rating. Factories, farms and commercial buildings use it routinely. Homes rarely need it, but as more households electrify, it's becoming more common.

Often, a load management device or an upgrade from a 60A to a 100A single-phase fuse solves the problem more cheaply. See upgrading your main fuse and 7kW vs 22kW EV chargers.

Three-phase supplies are provided by your Distribution Network Operator (DNO) – the company that owns the cables in your area, not your energy supplier. You apply to the DNO with details of your planned loads. They'll assess whether the local network can support it, then quote for the work. In some streets the cables already carry three phases and the upgrade is relatively simple; in others it means new cables from the substation.

Once the new supply is in place, an electrician installs a three-phase meter tails arrangement, a suitable consumer unit and any new circuits. Your energy supplier may need to fit a new meter. See who to call: supplier, network or electrician.

Timescales vary from a few weeks to several months. Speak to an electrician first – they can calculate your maximum demand and tell you whether three-phase is genuinely needed.