What this breaker is and why it matters
The Siemens 3VA1110-5EF42-0AA0-ZD00 is a 4-pole IEC frame 160 circuit breaker with a 55 kA interrupting capacity at 415 V — that's the 'class M' breaking capacity, meaning it'll safely clear a fault up to that level without the arc flashing over to the bus. The thermal-magnetic TM240 trip unit gives you adjustable overload protection from 70 A to 100 A (Ir), and short-circuit pickup (Ii) from 5 to 10 times the rated In of 100 A. That adjustability means you can dial it in for a specific motor or feeder load without swapping the breaker body.
What the ratings mean for your panel
The 55 kA Icu at 415 V is the maximum short-circuit current the breaker can interrupt once and still be serviceable (Ics is typically 100% of Icu on this series, but check the coordination study). The TM240 trip curve is thermal-magnetic — the thermal element handles overloads with a time delay, the magnetic element trips instantaneously on short circuits. Setting Ir between 70 and 100 A lets you match the breaker to a 100 A feeder or a motor with a lower FLA, and the Ii adjustment of 5-10x In gives you selectivity headroom against downstream branch breakers. The N conductor is unprotected on this variant, so it's meant for a 3-phase + N system where the neutral is not overloaded (typical for line-to-line loads only).