SENTRON 3VA1225-4GF42-0KC0 — 250 A MCCB for Line Protection
The Siemens 3VA1225-4GF42-0KC0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current at 40 °C, with a TM240 thermal-magnetic release and four poles. It is designated for line protection — meaning it sits upstream in a distribution panel, not as a motor-protective device. The 250 A rating holds flat through 50 °C (–), then derates to 223 A at 70 °C, so in a warm enclosure you still have headroom for a full 250 A feeder if ambient stays under 55 °C.
Breaking Capacity — What the Ratings Mean for Selectivity
This MCCB delivers 121 kA at 240 V, 75.6 kA at 415 V, 25 kA at 440 V, and 11.9 kA at 690 V. Those are the interrupting ratings at the respective system voltages — the number that governs whether the breaker clears a fault without upstream devices needing to open. For a 480 V panel (common in North America), the 25 kA at 440 V is the closest published figure; for a 400 V IEC installation, the 75.6 kA at 415 V gives substantial SCCR headroom for most industrial service entrances. The rated insulation voltage is 800 V, so it is rated for 690 V line-to-line applications.
Panel Fit and Auxiliary Wiring
Footprint is 140 mm wide × 158 mm high × 70 mm deep — a standard 4-pole MCCB envelope that fits most DIN-rail or panel-mount SENTRON bases. The front face carries IP40 protection, so it is suited for enclosed distribution boards; no washdown rating, so keep it behind a gland plate. It ships with 2 auxiliary switches HQ and a shunt trip (STL) auxiliary release, whose integrated trip coil order code is 3VA9688-0BL33. That shunt trip allows remote tripping from a PLC or emergency-stop circuit — useful for a curing-press line where you need to drop the feeder on a safety demand.