The Siemens SENTRON 3VA1225-6EF42-0AB0 is a 4-pole molded case circuit breaker rated 250 A at 40 °C with a TM240 thermal-magnetic overcurrent release, designed for line protection in distribution panels. Breaking capacity hits 220 kA at 240 V, 154 kA at 415 V, and still clears 17 kA at 690 V — this is a high-interrupting MCCB for fault levels common on large transformer secondaries or industrial busways. Rated insulation voltage is 800 V, so it handles 690 V line-to-line with margin on the insulation coordination.
Sizing and derating
Full 250 A rating holds up to 50 °C; above that it derates to 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C — factor the panel ambient before committing the BOM line. Power loss maxes at 57 W — that's the heat to vent in a sealed enclosure. Dimensions are 140 mm wide, 158 mm high, 70 mm deep — standard SENTRON 3VA form factor for 4-pole frames; fits existing DIN-rail or screw-mount patterns in a 400 V switchboard.
Lifecycle and sourcing
Listed as current production — no LTB or phase-out notice on this order code. The TM240 release is a fixed thermal-magnetic curve; no electronic trip unit, no communication function, no ground-fault monitoring — it's a straight line-protection breaker for standard feeder duty.