MCCB for line protection with high interrupting capacity
The Siemens 3VA1125-5EF32-0HA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection in three-phase distribution. Its 25 A continuous rating (Iu) holds across the 40–50 °C band without derating, then steps down to 22.5 A at 70 °C — useful to know when the breaker shares a crowded enclosure with other heat sources. The interrupting ratings are the headline: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. That 187 kA figure at 240 V places it well above typical utility fault levels in North American 120/240 V split-phase or 240 V delta services — useful where the available fault current exceeds 100 kA (large transformer banks, industrial substations). At 415 V the 121 kA covers most European industrial mains without needing a current-limiting upstream fuse. The TM240 thermal-magnetic release provides fixed thermal and magnetic trip thresholds. The shunt trip (STL) integrated as the auxiliary release allows remote tripping from an emergency-stop circuit or a PLC digital output — wired to the 3VA9688-0BL30 accessory trip unit listed in the spec.
Panel fit and mounting
Three-pole construction in a 76.2 mm wide (roughly 3-inch) footprint, 130 mm tall, 70 mm deep. The IP40 front face suits enclosed panel mounting where the door or cover provides the environmental seal. No auxiliary contacts are factory-fitted — the auxiliary contact version is listed as 'without', so any add-on signaling requires a field-installed accessory.