Residual Current Circuit Breaker (RCCB) is an electrical safety device that quickly disconnects a circuit that leaks current to earth. It is designed to protect equipment and reduce the risk of serious injury from sustained electrical shock. RCCBs work on the principle of residual current, which is current flowing through ground or other unintended paths due to insulation failure or other reasons. The RCCB detects this current and breaks the circuit to prevent electrical accidents.