100 A MCCB with ETU350 — what the ratings mean
The Siemens SENTRON 3VA2110-8HN36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated 100 A continuously across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling. That 100 A is the uninterrupted current (Iu) the breaker carries in normal service, not a trip threshold; the ETU350 electronic trip unit handles overcurrent protection with adjustable settings. The headline number here is the breaking capacity: 440 kA at 240 V, 330 kA at 415 V and 440 V, 220 kA at 500 V, and still 52.5 kA at 690 V.
This is a line-protection MCCB — it sits on the incoming feeder or a large subfeed, not on a motor branch. The 3-pole form factor and 105 mm width mean it occupies one standard MCCB slot in a Siemens SENTRON panelboard or a separate enclosure. Front IP40 is typical for a dead-front panel installation; not rated for washdown, so keep it inside the enclosure.