Siemens 5SY4232-7CV MCB, 15kA Icu 400V 2P C32

The Siemens 5SY4232-7CV is a 2-pole miniature circuit breaker from the SENTRON 5SY4 series, rated for a breaking capacity of 15 kA at 400 V AC. That 15 kA Icu (ultimate short-circuit breaking capacity) means it can safely interrupt a fault current up to 15,000 amps at 400 V without welding its contacts or failing catastrophically — critical for panel coordination when the upstream transformer can deliver that kind of energy. The C32 curve (C characteristic, 32 A rated current) trips magnetically at 5 to 10 times rated current, so it handles motor inrush and transformer energization without nuisance tripping while still clearing a hard short fast.