EV Charging Load

Electric vehicle charging represents a significant and growing load on electrical installations. Mode 2 charging from a domestic socket draws 2.3–3.7 kW, Mode 3 uses a dedicated EVSE with ratings from 7 kW (32A single-phase) to 22 kW (32A three-phase), and Mode 4 DC fast charging ranges from 50 kW to over 350 kW. EV charging is classified as a continuous load because vehicles may charge for hours at rated current — this means cables and protective devices must be rated for 100% of the charger demand without derating for intermittent duty. For multiple charger installations, diversity factors can be applied based on usage patterns: domestic overnight charging rarely sees all chargers at maximum simultaneously, allowing a diversity factor of 0.5–0.8 depending on the number of chargers. Load management systems can actively limit total demand by distributing available capacity among connected vehicles. BS 7671 Regulation 722 provides specific requirements for EV charging installations, including RCD types (Type A minimum, Type B for DC charging), cable sizing for continuous duty, and PME earthing considerations.