Information
Definition
Power supply refers to the electrical supply arrangement feeding a charger or group of chargers. It is normally assessed alongside phase availability, circuit capacity, protective devices, cable sizing and DNO/site constraints.
Why it matters
It determines charger capacity, protection, earthing, cable sizing, DNO considerations and whether load management is needed. For UK users, it affects installation cost, available charging power, protective device selection and how easily a site can be expanded.
References
Standards and regulations
BS 7671
BS 7671 is the UK national standard for electrical installations, covering the design, erection, inspection, testing and verification of low-voltage electrical systems. Section 722 contains specific requirements for supplies to electric vehicles.
ENA EREC G100
ENA EREC G100 is the UK Engineering Recommendation for customer export and import limitation schemes used to control power flow at a grid connection point. In EV charging it is relevant to load management, constrained connections, V2G export control and maximum import limitation.