250 A MCCB with ETU550 — what the ratings mean for your panel
The Siemens 3VA2225-5JP32-0DC0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current (Iu) in a 3-pole configuration, fitted with the ETU550 electronic trip unit. This is the line protection version — meaning it's configured for cable and busbar protection, not motor or generator protection, so the trip curve and accessories are selected accordingly. The 250 A rating holds at ambient temperatures up to 50 °C without derating — at 55 °C it's 238 A, at 60 °C it's 225 A, at 65 °C it's 213 A, and at 70 °C it's 200 A. If your panel runs hot (say, above 50 °C), you need to account for that reduction when sizing the downstream conductor. Breaking capacity is 187 kA at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 5.1 kA at 690 V. That 121 kA at 415 V gives serious fault-current headroom for most industrial distribution boards — you're not bumping up against the SCCR limit on a typical 415 V supply.
Trip unit, auxiliaries, and communication
The ETU550 is an electronic trip unit with communication capability (the order code suffix 0DC0 signals this). It includes an undervoltage release (UVR) as the auxiliary release design, and ships with 2 HQ auxiliary switches. The integrated auxiliary trip is order code 3VA9608-0BB25. The basic switch supplied is 3VA2225-5JP32-0AA0. Power loss is 50.5 W maximum at rated current — that's the heat you need to vent in a closed enclosure. The mechanical endurance is 20,000 operations (latching).
Physical fit and environment
Dimensions: 105 mm wide, 181 mm high, 86 mm deep. That 105 mm width is the standard 3-pole MCCB footprint for this SENTRON frame size — it mounts on a DIN rail or directly to a backplate. The depth of 86 mm means it clears most standard enclosure depths, but check gland-plate clearance if you're mounting it near the back wall. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Rated insulation voltage (Ui) is 800 V. No trip indicator, no voltage trigger, no phase failure detection, and no ground fault monitoring on this variant.