Short for Residual Current Breaker with Over-Current, an RCBO can detect when electric current exceeds a safe threshold or a short circuit occurs. It can swiftly disconnect the circuit when a fault current happens and prevent wiring damage. In this article, we explain what an RCBO is and how it. A residual-current device (RCD), residual-current circuit breaker (RCCB) or ground fault circuit interrupter (GFCI) is an electrical safety device, more specifically a form of Earth-leakage circuit breaker, that interrupts an electrical circuit when the current passing through line and neutral. ABB offers a total ev charging solution from compact, high quality AC wall boxes, reliable DC fast charging stations with robust connectivity, to innovative on-demand electric bus charging systems, we deploy infrastructure that meet the needs of the next generation of smarter mobility. Working Principle: RCCBs operate based on Kirchhoff's current law, detecting imbalances in the live and neutral wires and. The residual current device (RCD) or residual current circuit breaker (RCCB) enables the rapid disconnection of electricity, thereby avoiding prolonged and potentially serious shocks. But, in electrical terminology, what is RCCB? An RCCB measures any difference in the current.