An RCBO is a residual-current device (RCD) and a miniature circuit breaker (MCB) in one. The RCBO is designed to break an electrical circuit when the electrical current between the feed and return is not balanced. The RCBO will also protect against overload, the 'O' in RCBO standing for overcurrent protection. At C & W Berry we can supply a wide range of RCBO's from leading suppliers like Europa, Wylex and Contactum.