Siemens 3VA2612-5HL32-0AA0 circuit breaker 3VA2 IEC frame 1250 breaking capacity class M Icu=55kA @ 415 V 3-pole, line protection ETU320, LI, In=1250A overload protection Ir=500A ...1250A short circuit protection Ii=1,5...10 x In nut keeper kit