What it is and what it does
The Siemens SENTRON 3VA2225-5HN32-0DC0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 250 A and a breaking capacity of 187 kA at 240 V AC. That 187 kA figure means it can safely interrupt a fault current up to that level without welding contacts or cascading upstream — critical for high-fault installations like transformer secondaries or large motor control centers. The ETU350 electronic trip unit gives adjustable overload and short-circuit protection curves, so you can coordinate selectivity with downstream breakers.
Key ratings and what they mean for fit
Rated continuous current holds at 250 A from 40 °C through 50 °C ambient, then derates to 241 A at 55 °C and 213 A at 70 °C — no headroom loss in a typical 40 °C panel, but if your enclosure runs hot, check the derating curve. Breaking capacity drops with voltage: 121 kA at 415 V and 440 V, 79 kA at 500 V, and 5.1 kA at 690 V. At 690 V the 5.1 kA figure is the limiting factor; verify your available fault current at that voltage before specifying. Rated insulation voltage Ui is 800 V, so the breaker is insulated for 690 V systems with margin.
Integrated accessories and panel fit
This variant ships with an undervoltage release (UVR) as the auxiliary release — part number 3VA9608-0BB25 — and two auxiliary switches (HQ type). The UVR trips the breaker when control voltage drops, standard for emergency-stop or undervoltage protection schemes. No communication module, no ground-fault monitoring, no voltage trigger. Dimensions are 105 mm wide, 181 mm high, 86 mm deep — standard SENTRON 3VA frame size for 250 A, mounts on a DIN rail or panel-mount plate in a distribution board or MCC bucket.