What this MCCB is and what the ratings mean
The Siemens 3VA1125-4EF32-0AC0 is a SENTRON molded case circuit breaker (MCCB) sized for line protection in distribution panels — 3-pole, rated continuous current Iu of 25 A, with a TM240 thermal-magnetic release that provides fixed thermal and magnetic trip settings. The 25 A rating holds flat from 40 °C up to 50 °C; above that it derates to 24 A at 55 °C, 23.5 A at 60 °C, 23 A at 65 °C, and 22.5 A at 70 °C, so for a panel that runs warm the continuous load needs to stay under the derated curve, not the nameplate value. The interrupting ratings are the headline: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. For a 415 V industrial service the 75.6 kA SCCR means this breaker can safely clear a fault up to that level without welding contacts or cascading upstream — critical for selectivity coordination studies. The rated insulation voltage is 800 V, so it's comfortable on 690 V line-to-line systems. It carries two built-in auxiliary switches (HQ type) for remote status indication — no separate auxiliary module needed for basic open/closed signalling. There is no trip indicator, no undervoltage release, no ground-fault monitoring, and no communication function; this is a straightforward line-protection MCCB without add-on accessories. Front protection is IP40, suitable for enclosed panel mounting.
Panel fit and integration
The breaker measures 76.2 mm wide, 130 mm tall, and 70 mm deep — a standard 3-pole MCCB footprint that fits a 3-pole SENTRON mounting base or direct panel-mount. No special cutout or adapter plate required for a typical distribution panel. The TM240 release is factory-set; no field adjustment of the thermal curve, so the trip coordination is fixed once the breaker is sized to the downstream load.