The new residual current circuit breaker with self-diagnosis is designed to increase safety and provide an uninterrupted power supply to the electrical system. It was created to overcome the most frequently occurring problems in electrical systems: reliable circuit breakers and untimely tripping. Thanks to its innovative control logic and extremely sophisticated resetting mechanism it automatically carries out a weekly test on the release relay in the circuit breaker without turning off the power supply. In the event the circuit breaker trips, the device restores the power supply quickly, but only after it has carried out a thorough check on the state of insulation of the system. Thanks to LED indicators and the remote control contact, the user always knows that the device and the electrical system are working efficiently. If there is a problem with the circuit breaker or the electrical system, it is possible to intervene immediately and restore the required degree of safety.