What this breaker is and what the ratings mean
The Siemens 3VA1332-5EE32-0AA0-ZD00 is a 3-pole IEC frame 400 molded-case circuit breaker from the 3VA1 series, built for line protection with a thermal-magnetic trip unit (TM220, ATFM). Its headline rating is a 55 kA breaking capacity at 415 V (class M), which means it can safely interrupt a fault current up to that level without upstream devices needing to clear it — critical for selectivity in a distribution panel where you want the faulted branch to trip, not the main. The continuous current rating In is 320 A, with overload protection adjustable from 224 A to 320 A (Ir range) and a fixed short-circuit pickup Ii of 10 × In (3200 A). That fixed Ii suits motor or feeder circuits where a high inrush won't nuisance-trip, but the 320 A frame also means the breaker is sized for a 320 A bus, not a derated tap.