Siemens ground fault circuit 1 pole n 5su1 series tripping characteristic c siemens 5su1356 7kk13 the siemens 5su1356 7kk13 is a residual current operated circuit breaker rccb of characteristic type c this 13a circuit breaker is suitable for use in three phase current systems before input circuits with rectifiers type c is for the general device protection in control circuitsapplications include frequency converters medical devices and ups systems siemens 5su1356 7kk13 ground fault