Circuit-breaker IZMX16 ( Air circuit-breakers/switch-disconnectors), 3 pole, Current Range: Up to 4000 A, Rated current = rated uninterrupted current( In = Iu): 1000 A, up to 440 V 50/60 Hz( Icu): 42 kA, up to 440 V 50/60 Hz( Ics): 42 kA, Overload release, min.( Ir): 500 A, Overload release, max.( Ir): 1000 A, Installation type: Withdrawable, Standard/Approval: IEC, Protective function: Selective operation