What it is and what it does
The Siemens SENTRON 3VA1225-5GF42-0AD0 is a 4-pole molded case circuit breaker (MCCB) rated for 250 A continuous, built for line protection in industrial distribution panels. Its TM240 thermal-magnetic release handles overloads and short-circuits without external power — the thermal element tracks heating from sustained overcurrent, the magnetic element trips instantaneously on high fault current. The 187 kA interrupting rating at 240 V means it can safely clear a fault up to that level without rupturing or cascading damage upstream — critical for high-available-fault-current panels near transformers.
Breaking capacity across voltages
Interrupting capacity drops as voltage rises: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V. That 17 kA at 690 V suits it for 690 V industrial networks common in mining and heavy manufacturing — verify your system's prospective fault current against that figure.
Thermal derating and panel fit
Rated 250 A from 40 °C through 50 °C ambient, then derates linearly to 223 A at 70 °C — the operating limit. Panel footprint: 140 mm wide, 158 mm tall, 70 mm deep — standard for this frame size in the SENTRON 3VA family.