What this MCCB carries — and where it sits in a panel
The Siemens 3VA1225-5EF42-0CC0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current across a 40 °C to 50 °C ambient range, with a TM240 thermal-magnetic release and an undervoltage release (UVR) integrated. It's a 4-pole unit configured for line protection — meaning it sits on the incoming feeder, not on a motor branch or a downstream subfeed. The interrupting ratings climb to 187 kA at 240 V and 121 kA at 415 V, so it's sized for high-fault panels where the upstream transformer or utility tie can dump serious energy into a bolted fault. The 250 A rating holds flat through 50 °C — no derating needed in a typical 40 °C panel ambient — then drops to 243.3 A at 55 °C and 223 A at 70 °C. That thermal curve is the one to check if the breaker lives near a heat source or in a sealed enclosure with limited airflow.
Lifecycle and sourcing reality
This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.
Physical fit and panel integration
The 3VA1225-5EF42-0CC0 measures 158 mm high, 140 mm wide, and 70 mm deep. That's a standard 4-pole MCCB footprint for the 250 A frame — it mounts on a DIN rail or directly to a backplate via the screw terminals. The IP40 rating on the front means it's protected against tools and wires >1 mm, but not against dust ingress; it belongs inside a panel, not in a washdown zone. The integrated auxiliary contacts (2 auxiliary switches HQ) and the undervoltage release are wired separately — the UVR coil needs its own control voltage to keep the breaker closed. If the control voltage drops, the breaker trips. That's a common scheme for emergency-stop circuits or undervoltage protection on a feeder.