What this MCCB is and what it does
The Siemens SENTRON 3VA2225-5HN32-0CL0 is a 3-pole molded case circuit breaker (MCCB) rated for a continuous current Iu of 250 A, fitted with an ETU350 electronic trip unit for line protection. It carries a 187 kA interrupting rating at 240 V, 121 kA at 415 V and 440 V, 79 kA at 500 V, and 5.1 kA at 690 V — so the short-circuit rating drops sharply above 500 V, which matters when you're coordinating with upstream gear on a 690 V bus. The ETU350 is an electronic, not thermal-magnetic, trip unit — it gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves, which is what you want for selective coordination on a distribution panel feeding motor control centers or downstream sub-distribution.
Key ratings and what they mean for fit
Rated continuous current Iu of 250 A is the breaker's thermal capacity at 40 °C ambient; it holds 250 A up to 50 °C, then derates to 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. If your panel ambient runs above 50 °C, you need to account for that derating in your load schedule. Rated insulation voltage Ui is 800 V, so the breaker is rated for use on 690 V systems — the interrupting rating at 690 V is 5.1 kA, which is low enough that you'll want to verify the available fault current at that voltage level. The auxiliary contact configuration includes 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ type) — that gives you status feedback for PLC inputs, remote annunciation, and energy management systems without needing an external auxiliary contact block. It ships with an undervoltage release (UVR) as the auxiliary release design — the UVR is a separate order code (3VA9608-0BB24) that mounts inside the breaker. The basic switch variant is 3VA2225-5HN32-0AA0.
Where it goes in the panel
Dimensions are 86 mm deep, 105 mm wide, 181 mm tall — it mounts on a DIN rail or can be screw-fixed to a backplate. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss is 50.5 W — that's heat that has to be dissipated inside the enclosure, so factor it into your thermal calculation if the panel is densely packed.