The Siemens SENTRON 3VA1110-5EF32-0CH0 is a 3-pole molded case circuit breaker (MCCB) rated for 100 A continuous at 40 °C, using a TM240 thermal-magnetic release for line protection.
At 240 V this breaker can interrupt 187 kA — that's well above what most commercial panels see, so you're covered even on high-capacity transformer feeds. At 440 V it still clears 75.6 kA, and at 500 V or 690 V it holds at 17 kA. Those numbers mean the breaker can safely open under a dead short without welding contacts or blowing apart, which is what UL 489 and IEC 60947-2 certify for MCCBs. The thermal-magnetic TM240 release gives you fixed thermal pickup and magnetic trip settings tuned for cable and busbar protection — no field-adjustable dials to fumble with.
Thermal derating and real-world loading
At 55 °C it derates to 98 A, at 60 °C to 96 A, and at 65 °C to 94 A. At the max operating temp of 70 °C you're at 91 A. That's a gentle slope — you can push it near full rating in a warm panel without oversizing. Power loss at full load runs 27.5 W, so heat buildup is manageable in a standard enclosure with moderate airflow.