What this 250 A MCCB is and where it lands
The Siemens 3VA1225-4GF42-0BC0 is a SENTRON molded case circuit breaker (MCCB) rated at a fixed 250 A, 4-pole, designed for line protection in distribution panels. It carries an interrupting capacity of 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, 17 kA at 500 V, and 11.9 kA at 690 V — so the available fault current at the panel bus determines which voltage column governs the install. The 250 A rating holds flat from 40 °C through 50 °C, then derates to 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C; if the enclosure ambient runs above 50 °C, the continuous load must be trimmed accordingly.
Fit and panel integration
The breaker measures 70 mm deep, 140 mm wide, and 158 mm high — a 4-pole frame that occupies roughly the same footprint as other SENTRON 3VA fixed-thermal units. It ships with an undervoltage release (UVR) and two HQ auxiliary switches pre-installed, so the control wiring for the shunt trip and status feedback is already accounted for in the panel layout. The 59.5 W maximum power loss at full load means the enclosure ventilation should be sized for that heat rejection, especially if multiple breakers are ganged.