circuit breaker 3VA2 IEC Frame 1250 breaking capacity class M Icu=55 kA @ 415 V 3-pole, line protection ETU320, LI, In=1250 A overload protection Ir=500 A ...1250 A short-circuit protection Ii=1.5...10 x In nut keeper kit undervoltage release 24 V DC 4 auxiliary switches HQ