Information
Definition
Derating is the reduction of charger output or performance under certain conditions, such as high temperature, supply limits or component protection. It is normally assessed alongside phase availability, circuit capacity, protective devices, cable sizing and DNO/site constraints.
Why it matters
It affects real-world charging speed and helps protect equipment from overheating or operating outside safe limits. For UK users, it affects installation cost, available charging power, protective device selection and how easily a site can be expanded.