EV Charger RCD Selection in Europe: Type A-EV vs Type B
Quick answer: The correct RCD depends on the charger’s built-in DC leakage detection, the national wiring rules and the manufacturer’s instructions. A standard Type A alone may be unsuitable where smooth DC residual current can blind the device.
Why EV charging is different
Vehicle power electronics can produce AC, pulsating DC and smooth DC residual currents. Protection must disconnect dangerous earth leakage without becoming insensitive. The charger data sheet should state whether 6 mA DC detection is integrated.
Type A-EV and Type B
A Type A-EV solution is commonly built from Type A residual-current protection combined with verified 6 mA DC detection. Type B is designed to detect AC, pulsating DC and smooth DC residual currents over a wider frequency range. It is often chosen when the EVSE has no suitable built-in DC detection or when the project specification requires it.
Selection workflow
- Read the EVSE installation manual and declaration of conformity.
- Confirm single-phase or three-phase supply and maximum charge current.
- Check the local implementation of IEC 60364-7-722 and utility rules.
- Coordinate RCD rating with the circuit breaker and cable.
- Confirm earthing arrangement and any PEN-fault protection requirement.
- Test tripping and record results at commissioning.
Nuisance tripping and selectivity
Do not simply increase the trip rating. Investigate accumulated leakage, long cable runs, EMC filters and upstream/downstream coordination. Each charging point may require its own protection so a fault on one vehicle does not remove the entire car park.
Installer checklist
- Dedicated circuit and correct conductor size
- Overcurrent and residual-current protection
- Surge protection assessment
- Mechanical impact and IP rating
- Functional test under load
- Labels, test certificate and user handover
This is design guidance, not a substitute for national regulations or a qualified electrician.
