Single-Phase and Three-Phase AC Charging
Single-phase and three-phase AC charging describe how many alternating-current supply phases feed the EVSE and the vehicle's onboard charger. The number of phases can materially affect available charging power, but it does not determine power alone.
How phase count affects charging
In a single-phase connection, power is approximately voltage multiplied by current and power factor. In a balanced three-phase connection, power is approximately √3 multiplied by the line-to-line voltage, current, and power factor. A typical European 230 V, 16 A single-phase connection is therefore about 3.7 kW, while a 400 V, 16 A three-phase connection is about 11 kW before losses and other limits.
The car must be able to use the phases offered. A three-phase charge point does not make a single-phase onboard charger charge on all three phases, and some vehicles use only one or two phases under particular market configurations. The vehicle, EVSE, cable, circuit, building supply, and local load management can each impose a lower current or power limit.
Phase configuration is also separate from connector type. A Type 2 interface can support single-phase or three-phase AC, while the actual installation and vehicle determine what is used. DC fast charging does not feed grid AC directly into the vehicle's onboard charger; conversion occurs in the off-board charger instead.
For circuit sizing, fixed cables, socketed wallboxes, load balancing, and the difference between supply capacity and vehicle charging limits, see Home EV Charging.