The Siemens SENTRON 3VA2110-6HK32-0AA0 is a 3-pole molded case circuit breaker rated for 100 A continuous at 40 °C, with the same rating holding flat all the way up to 70 °C — no derating needed in a warm cabinet. Breaking capacity hits 242 kA at 240 V, 187 kA at 415 V, and still holds 121 kA at 500 V; at 690 V it drops to 3.7 kA, so on a 690 V system you'd want to verify the available fault current stays under that.
Power loss runs 10 W max at full load, which is manageable for thermal budgeting in a dense enclosure.
