The Siemens SENTRON 3VA2010-5HL42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 100 A continuous current across its entire operating temperature range — from 40 °C through 70 °C, the current rating holds flat at 100 A, no derating needed in a warm enclosure. Breaking capacity is the real story here: 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 3 kA at 690 V. This is a straightforward feeder or main breaker for a distribution panel.
Keep it inside the panel, not on the door.
Power loss and thermal considerations
Maximum power loss is 13.5 W. In a densely packed panel, that heat adds up — account for it in the enclosure's thermal budget.