What this MCCB carries — and what it doesn't
The Siemens 3VA1125-5EF36-0JC0 is a SENTRON molded case circuit breaker built for line protection — 3-pole, rated 25 A at 40 °C, with an interrupting capacity that hits 187 kA at 240 V and still holds 121 kA at 415 V. That kind of short-circuit rating means it can sit on the main feeder of a panel with high available fault current and still clear a bolted fault without the arc flashing upstream. The 800 V rated insulation voltage backs it for 480 V and 600 V class systems too. This variant comes factory-fitted with a shunt trip (STL) release and two HQ auxiliary switches — so you can electrically trip it from a remote pushbutton or a safety relay and get status feedback on the state of the breaker contacts. No undervoltage release, no ground-fault module, no communication stack. If your BOM calls for a plain line-protection MCCB with a shunt trip and aux contacts, this is a clean match. The frame measures 76.2 mm wide, 130 mm tall, 70 mm deep — a 3-pole MCCB that fits a standard distribution panel footprint. Power loss runs 8.5 W at full load, so panel heat rise is manageable even in a tightly packed enclosure.
Thermal derating and ambient range
The breaker holds its full 25 A rating from 40 °C up through 50 °C. At 55 °C it derates to 24 A, and at 70 °C it's still carrying 23 A. If your panel sits in a hot machine room or near a furnace line, the 3VA1 holds up better than a lot of thermal-magnetic breakers that start dropping current at 40 °C. Operating range spans -25 °C to 70 °C; storage from -40 °C to 80 °C.