What the ratings mean for fit
The Siemens 3VA2025-6HN36-0AA0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for a continuous current Iu of 25 A across the full ambient temperature range from 40 °C to 70 °C — no derating curve to chase, which simplifies panel schedules in warm enclosures. The ETU350 electronic trip unit provides adjustable overload and short-circuit protection, and the 242 kA breaking capacity at 240 V AC means it can interrupt a fault of that magnitude without cascading upstream — critical for high-fault locations like transformer secondaries or large motor control centers. Insulation voltage is rated 800 V, and the operating voltage goes to 690 V AC, so it holds the unit on the grid in 480 V or 600 V class systems without a voltage-rating penalty.
Breaking capacity across voltage classes
The interrupting rating drops predictably as voltage rises: 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 3 kA at 690 V. For a 480 V distribution panel, the 187 kA figure at 440 V is the applicable benchmark — well above typical available fault currents in most industrial switchboards, provided the upstream transformer impedance is within normal ranges. The steep drop to 3 kA at 690 V means this frame is not intended for high-fault 690 V applications; that would require a larger frame or a current-limiting fuse ahead of it.
Panel integration and environment
The 3VA2025-6HN36-0AA0 measures 105 mm wide, 181 mm high, and 86 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without gland-plate surprises. Front protection is IP40, meaning tools and fingers stay out, but the body is not sealed against washdown; keep it in a dry cabinet or behind a sealed door. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C, so it handles unheated warehouses and outdoor cabinets in temperate climates as long as condensation is managed. Power loss is 0.84 W maximum — negligible for thermal budgeting inside a crowded panel.