An RCD (Residual Current Device) breaker, also known as an RCCB (Residual Current Circuit Breaker) or GFCI (Ground Fault Circuit Interrupter) in some regions, is a safety device designed to protect people from electric shocks and prevent electrical fires caused by leakage currents. It works by detecting imbalances between the live and neutral wires and disconnecting the power supply if a leakage is detected.