RCD – Residual Current Device

An RCD is a safety device that automatically disconnects the electrical supply if it detects current leaking to earth (indicating a fault or electric shock hazard), required on all campsite hook-up supplies.

RCDs are mandatory for campsite hook-up connections in most European countries. They trip within 30 milliseconds of detecting a 30mA fault. Many motorhome mains systems include a built-in RCD in the hook-up socket.