What the interrupting ratings mean for panel coordination
The Siemens SENTRON 3VA1125-4EF32-0HA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying 25 A continuous current (Iu) with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity climbs to 121 kA at 240 V, then steps down to 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V — these are the fault currents it can safely clear at each voltage level without welding contacts or rupturing the arc chamber. For a 415 V distribution board, that 75.6 kA SCCR gives headroom above typical utility fault levels, so it coordinates downstream without forcing an upstream breaker to take the full hit.
Thermal derating and enclosure fit
The breaker holds its full 25 A rating from 40 °C through 50 °C ambient. At 55 °C it steps to 24 A, then drops gradually to 22.5 A at 70 °C. If this MCCB lives inside a sealed, uncooled panel near other heat sources, use the 55 °C or 60 °C column for your continuous-load calculation. Dimensions are 70 mm deep, 76.2 mm wide, 130 mm tall — a standard MCCB footprint that fits most SENTRON distribution blocks and busbar systems without adapters. Front protection is IP40, so it's fine for a clean indoor panel but not for washdown zones.
Integrated shunt trip and auxiliary release
This version ships with a shunt trip (STL) auxiliary release designed for remote tripping — energize the release coil and the breaker opens regardless of load current. The integrated auxiliary trip is specified as order code 3VA9688-0BL30, so if you're replacing an existing unit, verify that the same release module is fitted or order the matching spare. There is no undervoltage release, no auxiliary contact block, and no communication module on this variant; those are separate add-ons if the application requires them.