What it is and where it fits
The Siemens SENTRON 3VA1125-3EF32-0JC0 is a 3-pole molded case circuit breaker (MCCB) rated 25 A continuous at 40 °C, designed for line protection in distribution panels and industrial switchboards. It carries a rated insulation voltage of 800 V and delivers a breaking capacity of 75.6 kA at 240 V, 52.5 kA at 415 V, and 32 kA at 440 V — numbers that tell you it handles high-fault-current scenarios common in industrial mains and sub-distribution. The 70 mm depth and 76.2 mm width mean it fits standard SENTRON mounting bases and panel cutouts without rework.
Thermal performance and real-world current
The 25 A rating holds flat from 40 °C up to 50 °C. At 55 °C it derates to 24 A, at 65 °C to 23 A, and at 70 °C to 23 A — still usable in warm enclosures. The maximum power loss is 8.5 W, which matters when calculating heat rise in a sealed panel. Operating range is -25 °C to 70 °C, storage from -40 °C to 80 °C.
Built-in accessories and wiring
This variant ships with two auxiliary switches (HQ design) and a shunt trip (STL) release factory-fitted — no field kit to order separately. The auxiliary switches give remote status for the breaker position (open/closed/tripped), and the shunt trip lets a control system or E-stop pushbutton force the breaker open. No undervoltage release, no ground-fault monitoring, no communication module on this version. The basic switch assembly is order code 3VA11253EF320AA0 if you ever need the core mechanism alone.