What this MCCB carries — and what it doesn't
The Siemens SENTRON 3VA2225-6HL32-0CA0 is a 3-pole molded case circuit breaker rated for line protection at 250 A continuous current (Iu). Its ETU320 electronic trip unit handles overload and short-circuit curves without a communication module or phase-failure detection — this is a straight line-protection breaker, not a power-monitoring device. The 242 kA breaking capacity at 240 V (187 kA at 415 V, 121 kA at 500 V, 6 kA at 690 V) gives serious fault-current headroom for distribution panels downstream of large transformers. An integrated undervoltage release (UVR) is built in; auxiliary contacts are not included on this variant.
Thermal derating — the real-world current limit
At 40 °C, 45 °C, and 50 °C the breaker holds its full 250 A rating. Above that it steps down: 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 60 °C, you're sizing for 232 A continuous, not 250. The maximum power loss is 50.5 W — that heat has to leave the enclosure, so factor it into your thermal calculation for the gland plate and fan sizing.
Dimensions and panel fit
The breaker measures 105 mm wide × 181 mm high × 86 mm deep. That 86 mm depth is the body only — add clearance for the arc chute and wiring channels. It mounts on a standard DIN rail or panel-mount plate; the 3-pole footprint matches the SENTRON 3VA2 frame family, so if you're swapping into an existing panel that held a 3VA2-series MCCB, the cutout and busbar spacing should carry over.
Environmental limits
Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage limit governs handling and warehousing, not running conditions. Rated insulation voltage is 800 V, which covers 480 V and 600 V class systems with margin.