SENTRON 3VA1110-6MH32-0AF0 — 100 A MCCB with 220 kA interrupting capacity
The Siemens SENTRON 3VA1110-6MH32-0AF0 is a 3-pole molded case circuit breaker (MCCB) rated for 100 A continuous at 40 °C, with a TM120M thermal-magnetic overcurrent release. Its interrupting capacity hits 220 kA at 240 V — that's the short-circuit current it can safely clear without welding contacts or venting plasma into the panel. At 415 V it still holds 154 kA, dropping to 121 kA at 440 V and 7.5 kA at both 500 V and 690 V. The design is explicitly for starter protection, meaning it's sized to sit ahead of a motor contactor and handle the high inrush without nuisance tripping, while still protecting the branch circuit under fault. The breaker carries a built-in auxiliary switch configuration: one auxiliary switch plus one trip alarm switch (HQ type), so you get a separate signal for the breaker's open/closed state and a dedicated contact that closes only on a trip event. That trip alarm is useful for remote fault annunciation — it stays closed after a trip until manually reset, which a standard aux contact won't do. The supplied basic switch is order code 3VA11106MH320AA0, meaning the internal mechanism is a separate line item if you ever need to replace just the switch block without swapping the whole breaker.
Thermal derating and panel fit
The 100 A rating holds flat from 40 °C through 50 °C — no derating needed in a warm enclosure. At 55 °C it drops to 98 A, then 96 A at 60 °C, 94 A at 65 °C, and 91 A at 70 °C. If your panel ambient sits above 50 °C, size the load side for the derated value, not the nameplate 100 A. The breaker measures 76.2 mm wide, 130 mm high, and 70 mm deep — standard 3-pole MCCB footprint for a 100 A frame, so it drops into most existing panel layouts without re-drilling the mounting plate. Maximum power loss is 25 W at rated current. That's the heat the breaker dumps into the enclosure — for a single unit in a ventilated panel it's fine, but stack several in a sealed box and you'll need to account for the cumulative thermal load. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The insulation voltage is rated at 800 V, so the breaker's internal clearances are designed for 690 V systems with margin.