20120069484 | RESIDUAL-CURRENT CIRCUIT BREAKER - A residual-current circuit breaker includes at least one summation current transformer through which are guided at least one first conductor and one second conductor of an electric network to be protected. At least one secondary winding is arranged on the summation current transformer and connected in terms of circuitry to a trip element. A test circuit connects the first conductor with the second conductor and includes at least one first test resistor, a second test resistor arranged serially in relation to the first test resistor in terms of circuitry, and a test button. The second test resistor is bridged by a shunt line which is guided through the summation current transformer. Arranged in the shunt line in terms of circuitry is at least one first voltage-dependent resistor. | 03-22-2012 |