What it is and what the ratings mean
The Siemens SENTRON 3VA2010-5HN32-0AC0 is a 3-pole molded case circuit breaker rated for 100 A continuous current, fitted with an ETU350 electronic trip unit for line protection. The 187 kA breaking capacity at 240 V means this breaker can safely interrupt a fault current up to that level without welding contacts or cascading failure upstream — critical for high-fault installations like transformer secondaries or large motor control centers. At 415/440 V it still holds 121 kA, and at 690 V it drops to 3.4 kA, so the voltage class of your distribution determines the available fault current it can handle.
Thermal derating and panel fit
The breaker carries its full 100 A rating from 40 °C up to 50 °C, then derates to 96.25 A at 55 °C, 92.5 A at 60 °C, 88.75 A at 65 °C, and 85 A at 70 °C. If your panel ambient runs above 50 °C, you need to account for that reduction in the load schedule. The 105 mm width and 86 mm depth fit standard SENTRON panel footprints, and the front IP40 protection handles typical enclosure interior conditions.