What this MCCB carries and where it fits
The Siemens 3VA2225-7KP32-0DH0 is a SENTRON molded case circuit breaker rated for 250 A continuous at 40 °C through 50 °C, with a 3-pole line-protection design. Its interrupting capacity reaches 330 kA at 240 VAC and 242 kA at 415/440 VAC — enough for high-fault utility feeds or transformer secondaries where SCCR headroom matters. The breaker includes an undervoltage release (UVR) and a communication function, plus a configurable auxiliary switch block — 2 auxiliary switches plus a separate trip alarm switch (HQ design). That means the panel builder gets both remote status and a dedicated alarm contact without adding an external module.
Derating and thermal limits
Rated 250 A from 40 °C to 50 °C ambient, the breaker derates to 238 A at 55 °C, 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C. If your panel internal ambient runs above 50 °C, size the load accordingly — the 250 A nameplate holds only up to that point. Maximum power loss is 50.5 W. In a sealed enclosure with multiple breakers, that heat adds up — factor it into your thermal budget rather than assuming the nameplate current is usable everywhere.
Footprint and panel integration
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep. That 86 mm depth is the key dimension for shallow backpanel enclosures — verify gland-plate clearance before committing the layout. Mounts on a standard DIN rail or direct-panel via the SENTRON base plate. The 3-pole block occupies three module widths (105 mm total), so it fits the same grid as other 3VA frame sizes.