What this MCCB carries and where it fits
The Siemens 3VA2225-5KP42-0KD0 is a SENTRON molded case circuit breaker (MCCB) rated 250 A at 40 °C, in a 4-pole configuration with an ETU850 electronic trip unit. The 187 kA breaking capacity at 240 V means it can safely interrupt very high fault currents without cascading upstream — essential for main feeders in industrial switchboards where the available fault current is high. At 415 V the rating holds at 121 kA, and it still manages 75.6 kA at 500 V, so it covers most low-voltage distribution panels in North American and European installations. The ETU850 trip unit gives you adjustable overload and short-circuit protection curves, plus communication capability for power monitoring and remote trip indication. The three HQ auxiliary switches let you wire status feedback to a PLC or SCADA without extra contact blocks. Rated insulation voltage is 800 V, so it's comfortable on 480 V and 600 V class systems.
Thermal derating and panel integration
The 250 A rating holds flat from 40 °C through 50 °C — no derating needed in most ventilated enclosures. At 55 °C it drops to 238 A, at 60 °C to 225 A, and at 70 °C to 200 A. If your panel ambient runs hot, size the downstream bus and cable for the derated figure, not the nameplate. The 86 mm depth and 140 mm width fit standard MCCB mounting footprints in distribution panels; front IP40 protection handles typical switchgear environments.