What this 250 A MCCB carries — and where it fits
The Siemens 3VA2225-6HN42-0BH0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A maximum continuous current, with a 4-pole configuration and an interrupting capacity of 242 kA at 240 V. That interrupting rating drops to 187 kA at 415 V and 440 V, then to 121 kA at 500 V, and to 4.5 kA at 690 V — so the available fault current at your service voltage determines whether this frame is adequate. The ETU350 electronic trip unit handles the overcurrent protection curve, and the breaker includes an undervoltage release (UVR) plus two auxiliary switches and one trip alarm switch HQ.
Thermal derating — the real current you can run
At 40 °C, 45 °C, and 50 °C the breaker holds its full 250 A rating. At 55 °C it derates to 241 A, at 60 °C to 232 A, at 65 °C to 222 A, and at 70 °C to 213 A. If your panel ambient runs above 50 °C, the continuous load must be sized against the derated figure, not the nameplate 250 A.
Physical footprint and panel fit
Dimensions are 86 mm deep, 140 mm wide, and 181 mm high. The 140 mm width across four poles is the key panel-space constraint — standard for a 4-pole MCCB in this frame size. The 86 mm depth fits most distribution board enclosures without gland-plate interference.