What the interrupting ratings mean for your panel
The Siemens SENTRON 3VA2225-5JQ42-0DH0 is a 4-pole molded case circuit breaker rated 250 A, designed for line protection in distribution panels. Its interrupting capacity hits 187 kA at 240 V and 121 kA at 415 V and 440 V — that's the fault current it can safely clear without welding contacts or venting plasma into the enclosure. At 500 V it still holds 75.6 kA, and at 690 V it drops to 4.5 kA, so the voltage class of your system determines the available fault current it can handle. The breaker carries a trip indicator and an undervoltage release (UVR) built in, plus two auxiliary switches and one trip alarm switch (HQ configuration). Thermal derating matters here: the breaker carries a full 250 A up to 50 °C ambient. At 55 °C it derates to 238 A, at 60 °C to 225 A, at 65 °C to 213 A, and at 70 °C to 200 A. If your panel runs hot — say a packed enclosure near a furnace line — size the continuous load against the derated value, not the nameplate 250 A. The 3VA2225-5JQ42-0DH0 includes a communication function, which means it can integrate with a higher-level monitoring system for remote trip indication and load management. Power loss at full load is 50.5 W maximum — factor that into your enclosure thermal budget if you're stacking several breakers in a confined space.
Panel fit and mounting
Dimensions are 181 mm high, 140 mm wide, 86 mm deep. It mounts on a DIN rail or can be screw-fixed to a backplate in a standard distribution panel. The 4-pole form factor means it occupies four module widths — plan your enclosure fill accordingly. The undervoltage release (UVR) is factory-fitted, so no field wiring of a separate shunt trip is needed for safety circuits that drop the breaker on loss of control voltage.