What the ratings mean for fit
The Siemens SENTRON 3VA2225-8HM32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current of 250 A at 40 °C through 50 °C. That 250 A holds flat across the first 10 °C of ambient rise — useful in a crowded panel where the internal temperature sits around 50 °C. Above that, the thermal derating curve kicks in: 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. If your enclosure runs hot, size the load to the 70 °C figure, not the nameplate 250 A. The interrupting rating is where this breaker earns its panel space. It clears 440 kA at 240 V, 330 kA at 415 V and 440 V, 220 kA at 500 V, and still holds 52.5 kA at 690 V. That 440 kA at 240 V means it can sit on the secondary side of a large distribution transformer without needing a current-limiting fuse upstream — the breaker itself handles the full available fault current. At 690 V the 52.5 kA rating still covers most industrial motor-drive feeds. The adjustable thermal-magnetic trip is set with a full-scale of 250 A and an initial value of 50 A. No undervoltage release, no voltage trigger, no communication module — this is a straight line-protection breaker. The ground-fault monitoring uses summation current formation on the L-conductor, so it detects leakage without a separate CT block. No trip indicator on the front; you'll know it tripped when the line goes dark.
Panel fit and environment
Mounts on a DIN rail or direct panel. Dimensions: 105 mm wide, 181 mm tall, 86 mm deep. That 86 mm depth is the body only — leave clearance for the arc chute exhaust and outgoing cable bends. Operating range is -25 °C to 70 °C; storage from -40 °C to 80 °C. Max power loss at rated load is 48 W — factor that into your enclosure thermal budget if you're stacking several breakers in a row.