Three-phase charger: do you need load balancing?

A three-phase home has three conductors of 230 volts each. A charger that uses all three can deliver much more power than on one phase. On one phase the maximum is around 7.4 kW. On three phases 11 kW is common, which comes to about 16 amps per phase. 22 kW needs about 32 amps per phase.

How fast your car really charges is up to the car itself. When charging at home, the charger inside the car sets the limit. Many electric cars charge at home at 11 kW at most, quite a few at 7.4 kW. That is why 11 kW is the sensible maximum for almost everyone; the trade-off is in 11 or 22 kW charger.

A charger gets its own circuit in the fuse box, separate from your other appliances. For 11 kW that is a 3x16 amp circuit. It fits most three-phase homes without upgrading the supply itself.

For 22 kW you need a 3x32 amp circuit, and that almost never fits without a heavier connection. Upgrading is possible, but you pay the grid operator a one-off connection fee and a higher fixed tariff after that. In areas with grid congestion it can also take longer before a heavier connection is in place. Installing the circuit falls under the Dutch installation standard NEN 1010 and is a job for an installer.

The hard part is not the charger's power, but what your home draws at the same time. Not every appliance runs at once, but a charger and a heat pump can both draw full power for hours. How to estimate that is in our explanation of the diversity factor.

If you mainly charge on solar power, the charger follows your solar surplus. That is almost always less than 11 kW, so you do not need three phases for it. How that works is in charging on solar power.

With a 3x25A connection and an 11 kW charger, about 6 kW is left for your home. With a heat pump or induction cooking that is tight, so you need load balancing. With 3x35A there is more room and it is usually not needed.

A dedicated 3x16 amp circuit. It fits most three-phase homes. A 22 kW charger needs 3x32 amps, and that almost never works without an upgrade.

Whether your charger can also run on one phase is in its specifications. On one phase the maximum is about 7.4 kW. For most drivers that is plenty with a night to charge.

For 11 kW usually not, if your home already has three phases. For 22 kW almost always. Upgrading costs a one-off connection fee and then a higher fixed tariff at the grid operator, so only do it if your car really uses that power.

A charger gets its own circuit in the fuse box and that work falls under the NEN 1010 installation standard. So have it done by an installer. During the survey we also check straight away whether you need load balancing. Ask your question or see our charger page.