What this MCCB is and what it does
The Siemens SENTRON 3VA1110-4EF32-0AF0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 100 A. It uses a TM240 thermal-magnetic overcurrent release — a fixed, non-adjustable trip unit that responds to both overload (thermal) and short-circuit (magnetic) events. The 100 A rating holds flat from 40 °C up to 50 °C; above that it derates to 96 A at 55 °C, 94 A at 60 °C, 92 A at 65 °C, and 90 A at 70 °C, so a panel running warm near the top of its operating range loses about 10 % of the continuous rating. Breaking capacity is what decides whether this breaker clears a fault without welding or rupturing. At 240 V it interrupts 121 kA; at 415 V it handles 75.6 kA; at 440 V it drops to 52.5 kA; and at 690 V it still holds 11.9 kA. That means it can sit downstream of a large transformer or generator bus without needing a current-limiting fuse ahead of it — the SCCR of the panel can be built around these numbers. The auxiliary contact block is factory-fitted as 1 auxiliary switch plus 1 trip alarm switch (HQ version), so the panel gets both a status mirror and a separate alarm signal on trip without adding a side-mount module. No undervoltage release, no shunt trip, no communication module — this is a straight line-protection breaker with no add-on accessories.
Where it fits and how it mounts
The 3VA1110-4EF32-0AF0 mounts on a DIN rail or directly to a backplate; the 70 mm depth, 76.2 mm width, and 130 mm height match the standard 3VA frame footprint. Front IP40 means it is protected against tools and wires >1 mm but not against water — keep it inside a closed panel or enclosure. The operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C.