... ,5SM1 residual current circuit breaker ,Siemens type(ELCB,RCCB,RCD) Like Siemens Circuit Breaker, Residual current circuit breaker,RCCB,ELCB,RCD,RCBO,MCB,DPNLE(DZ30LE ... the right amp, if not ,the products cannt protect the circuit.b. TEST button should be tested four times one month ... current, if not, the product havenot overload current and short circuit protection functions