MCCB for high-fault panel positions
The Siemens 3VA1112-6FD46-0AA0 is a 4-pole SENTRON molded case circuit breaker rated 125 A continuous (Iu) with a TM210 thermal-magnetic release — fixed thermal, magnetic adjustable from 5× to 10× In (li max 1250 A). Its interrupting ratings are what earn it a spot at the main or large-feeder position: 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, and still 17 kA at 690 V. That 220 kA at 240 V means it can sit ahead of a transformer or service entrance where fault current is high — no need for a current-limiting fuse upstream to protect the breaker.
Thermal derating and panel fit
Full 125 A rating holds through 50 °C ambient; above that it derates linearly to 114 A at 70 °C. Dimensions are 101.6 mm wide × 130 mm high × 70 mm deep — a 4-pole frame that fits standard SENTRON mounting plates and busbar systems. IP40 on the front is typical for panelboard installation; the enclosure provides the rest of the seal.