What this breaker is and what it does
The Siemens 3VA1220-5GE42-0AA0-ZD00 is a 4-pole molded case circuit breaker on the 3VA1 IEC frame 250 platform, rated In=200A with a TM220 thermal-magnetic trip unit (ATFM). Its Icu=55kA at 415V places it in breaking capacity class M — the mid-range tier for this frame, meaning it handles high-fault industrial feeds without needing a current-limiting upstream device in most 415V distribution panels. The overload protection band Ir=140A...200A gives you a 30% adjustment range below the fixed rating, and the short-circuit pickup is fixed at Ii=10 x In (2000A). The N conductor is protected at 100%.
What the key ratings mean for your panel
The 55kA Icu at 415V is the ultimate breaking capacity — the breaker can safely interrupt one fault at that level and still be functional afterward (though you'd replace it after a fault near that magnitude). For coordination studies, the service breaking capacity Ics is typically 50% of Icu on this class M frame, so expect 27.5kA for routine fault clearing without replacement. The TM220 trip unit is thermal-magnetic: the thermal element handles overloads (Ir adjustable 140-200A) with an inverse-time curve, and the magnetic element handles short-circuits at a fixed 10x In. The 100% N protection means the neutral pole is fully rated and trips with the phase poles — important for 4-wire systems where you can't allow an open neutral.