What you're looking at
The Siemens 3VA2110-5HN42-0KH0 is a 4-pole IEC frame 160 molded-case circuit breaker with a 55 kA breaking capacity at 415 V — that's class M, meaning it handles moderate fault levels common in industrial distribution without needing a current-limiting upstream device. The ETU350 electronic trip unit gives you LSI protection (long-time, short-time, instantaneous) plus adjustable neutral protection (OFF, 50%, or 100% of phase setting). Rated In is 100 A, with overload Ir adjustable from 40 A to 100 A and short-time pickup Isd from 1.5 to 10 × Ir.
What the ratings mean for fit
The 55 kA Icu at 415 V is the ultimate breaking capacity — the breaker can safely interrupt a fault of that magnitude once and still be functional afterward. For most industrial panel applications, that's enough to coordinate with a downstream transformer or a 400 V motor control center without cascading. The ETU350's LSI curve lets you set short-time delay (Isd) to ride through motor inrush or downstream breaker coordination, then clear hard faults fast. The adjustable neutral is a nice touch for 3-phase + N panels where you need to protect the neutral conductor at a lower rating than the phase conductors — common in harmonic-rich loads like VFD banks or UPS inputs.
Panel integration notes
Mounts on a standard DIN rail or directly to a backplate via the frame's mounting holes. The nut keeper kit is included, which saves time when you're torqueing down lugs in a tight enclosure — no dropped hardware. The shunt trip wiring lands on the left-side terminals; keep the control circuit separate from the power conductors to avoid induced pickup on the trip signal. The auxiliary switch and trip alarm switch are pre-wired to a common terminal block on the front face, so you can land your PLC inputs without opening the breaker cover.