What it is and what it handles
The Siemens SENTRON 3VA1110-5EF36-0CC0 is a 3-pole molded case circuit breaker (MCCB) rated 100 A continuous at 40 °C, designed for line protection in distribution panels. Its interrupting capacity scales with system voltage: 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V — meaning it clears high-fault currents on the secondary side of a step-down transformer or in a 480 V industrial feeder without cascading upstream.
Thermal derating and panel integration
The breaker holds its full 100 A rating up to 50 °C ambient; above that it derates linearly to 91 A at 70 °C. That matters when the breaker shares a DIN-rail enclosure with other heat sources — the 70 mm depth and 76.2 mm width (3-inch footprint) fit standard panel-mount cutouts, but you need to account for the 27.5 W power loss at full load when sizing ventilation.