What this MCCB is and what it does
The Siemens 3VA1110-3FE46-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection — the go-to for feeding downstream distribution or a single heavy load in a panel. Rated at 50 A continuous, it's a fixed-current breaker; no adjustment dial on the TM220 trip unit. That means you spec it for a known load and leave it. Four poles give you three-phase + neutral protection, which matters when you're feeding a 3-phase panel with a solid neutral that can't share a common trip. The interrupting ratings climb with voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That's enough headroom for most industrial services — the 415 V figure covers common European 400 V systems with margin.
Thermal derating and panel integration
This breaker holds 100 A through 50 °C ambient — no derating needed in a typical ventilated enclosure. Above that it steps down: 98 A at 55 °C, 96 A at 60 °C, 94 A at 65 °C, and 91 A at 70 °C. If your panel runs hot (sunlit roof, next to a drive cabinet), the 70 °C figure is the one to plan around. Dimensions are 130 mm high, 101.6 mm wide, 70 mm deep — a compact footprint for a 4-pole 50 A MCCB. IP40 on the front means it's protected against tools and wires >1 mm, but not against water; keep it inside a closed panel. The 25 W max power loss is manageable but worth adding to your enclosure heat budget if you're stacking several breakers.