What it is and what the ratings mean
The Siemens SENTRON 3VA1110-4EF36-0AC0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection — meaning it sits upstream protecting a feeder or distribution bus, not a specific motor or load with its own overload relay. Rated 100 A continuous at 40 °C, it carries the full 100 A up to 50 °C before it starts to derate: 98 A at 55 °C, 96 A at 60 °C, 94 A at 65 °C, and 91 A at 70 °C. If your panel ambient runs hot, that derating curve is what governs the real ampacity — not the 100 A label. Breaking capacity is where this breaker earns its keep: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. Those numbers tell you it can safely interrupt a fault up to those levels without welding contacts or venting arc — critical when the available fault current at the panel is high. The TM240 thermal-magnetic release handles the overload and short-circuit trip curve; no undervoltage release or shunt trip is fitted as standard. Rated insulation voltage is 800 V, so it's comfortable on 690 V systems with margin. Power loss runs 25 W maximum at rated current — that's heat that stays inside the enclosure, so factor it into your thermal budget if the panel is densely packed.
Physical fit and auxiliary configuration
Footprint is 76.2 mm wide by 130 mm tall by 70 mm deep — that's 3 inches wide, 5.12 inches tall, 2.76 inches deep. It mounts on a DIN rail or direct-panel bolted; the 3-pole width matches standard MCCB panel cutouts for that frame size. The breaker ships with two auxiliary switches (HQ type) fitted, so you get remote status indication without buying add-on modules. No communication module, no ground-fault monitoring, no trip indicator flag, and no undervoltage release on this variant. If you need any of those, the 3VA1110 family has other order codes that carry them — this one is the straight line-protection version with aux switches only.