The Schneider Electric C12B3TM125B is a ComPacT NSXm moulded-case circuit breaker (MCCB) rated 125 A at 40 °C, with a 25 kA interrupting capacity at 415 V AC — performance level B per IEC 60947-2. The TM-D trip unit is thermal-magnetic, so it provides both overload (thermal) and short-circuit (magnetic) protection in one device, set at the factory to the 125 A rating.
Dimensions are 81 mm wide by 137 mm high by 80 mm deep — a compact footprint for a 125 A MCCB, fitting standard 35 mm DIN-spaced busbar systems (pitch 35 mm with spreaders, 27 mm without). Front connections top and bottom accept compression lugs or busbars, so panel wiring is straightforward with no rear-access requirement. IP40 enclosure protection keeps out tools and small particles; IK07 impact rating means it survives a 2 J hammer blow typical of switchgear handling.
This is a standard catalogue item from the ComPacT NSXm family, widely specified in distribution boards across Europe and Asia. For volume or project-level pricing, submit an RFQ with target quantity and delivery window.
Operating altitude is 2000 m without derating, 5000 m with derating — relevant for high-altitude sites where air density affects arc extinction. Relative humidity range 0–95 % non-condensing. Electrical durability is 20,000 cycles at 440 V at rated current, 10,000 cycles at twice rated current; mechanical durability matches at 20,000 cycles.