What this MCCB carries — and what it means for your panel
The Siemens 3VA1225-5GF42-0CH0 is a SENTRON molded case circuit breaker rated at a solid 250 A continuous, non-derated from 40 °C through 50 °C — at 55 °C it still holds 243 A, and at 70 °C it's still good for 223 A. That means in a warm enclosure you're not losing headroom until the ambient climbs past 50 °C. Interrupting capacity is the headline: 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 187 kA figure at 240 V tells you this breaker is built for high-fault service-entrance or large-distribution positions where the available fault current is serious — not a branch-circuit afterthought. Four poles, line-protection design, and it ships with an undervoltage release (UVR) integrated — so it drops the load on loss of control voltage without an external relay. The auxiliary switch complement is 2 aux switches plus 1 trip alarm switch HQ, which gives you both status and alarm feedback to a PLC or annunciator.
Footprint and panel fit
Dimensions are 140 mm wide × 158 mm tall × 70 mm deep — a standard SENTRON 3VA frame size. It mounts on a DIN rail or direct panel plate; the 70 mm depth keeps it clear of shallow enclosure back-panels. No communication function onboard, so no comms wiring to route — just power and the UVR coil circuit.
What the ratings mean for the buyer's decision
The 250 A rating is the maximum continuous current the breaker carries without tripping under normal load. The interrupting capacities at each voltage level tell you the worst-case fault this breaker can safely clear. Insulation voltage rated at 800 V — so it's suitable for 690 V systems with margin. The UVR is factory-fitted, not a field-add kit, which saves installation time and avoids wiring errors on the control circuit.