RCCB : Are used in all system up to 240/415 V AC, Devices of type AC trip in the event of sinusoidal AC residual currents, type A also trips in the event of pulsating DC residual currents. RCBO : Are combination of an RCCB and miniature circuit breaker in a compact design for personnel, fire and line protection. For personnel protection and fire protection, the residual current part of the type AC trips in the event of sinusoidal AC residual currents, type A also trip in the event of pulsating DC residual currents.