MCCB with ETU850 — 250 A, 187 kA interrupting capacity
The Siemens SENTRON 3VA2225-5KP32-0JH0 is a 3-pole molded case circuit breaker rated for 250 A continuous current at 40 °C, carrying a full 250 A through 50 °C before derating begins at 55 °C (238 A) and stepping down to 200 A at 70 °C. That 250 A frame holds across a wide ambient range — useful in a warm panel where a standard 250 A breaker would already be derated. The ETU850 electronic trip unit provides adjustable overload and short-circuit protection with communication capability, plus a shunt trip (STL) for remote opening. Interrupting capacity hits 187 kA at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 5.1 kA at 690 V — so it handles high-fault utility feeds downstream of a transformer without cascading upstream. Rated insulation voltage is 800 V, and the breaker includes a voltage trigger and trip indicator as standard. The auxiliary contact configuration is 2 auxiliary switches plus 1 trip alarm switch (HQ designation). Max power loss is 48 W, and latching endurance is rated at 20 000 operations. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Panel integration and footprint
The breaker measures 105 mm wide × 181 mm high × 86 mm deep — a standard SENTRON 3VA2 frame size. It mounts directly onto a DIN rail or can be screw-fixed to a backplate. The 86 mm depth is shallow enough to clear a 200 mm deep enclosure with room for wiring gutters. The ETU850 trip unit is front-accessible for setting adjustments without removing the breaker from the panel.