What it is — and what the ratings mean for fit
The Siemens SENTRON 3VA2025-7HM36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 25 A continuous at 40 °C through 70 °C — no derating needed across that band. The interrupting capacity hits 330 kA at 240 V, 242 kA at 415 V, and still delivers 187 kA at 500 V, dropping to 3 kA at 690 V. That 330 kA figure at 240 V means it can safely clear a fault on a high-capacity transformer secondary without the arc re-striking or the case rupturing — critical for main feeders in large distribution panels. The ETU330 electronic trip unit handles the overcurrent protection curve. This is the line-protection version (not motor-protection), so the trip characteristics are set for cable and busbar protection rather than motor inrush. The ground-fault monitoring uses summation current formation on the L-conductor — it sums the phase currents and trips if the vector sum exceeds the threshold, which catches arcing faults to ground without needing a separate neutral CT. Dimensions are 105 mm wide, 181 mm tall, 86 mm deep — a standard SENTRON 3VA fixed-breaker footprint that fits the existing panel cutouts and busbar risers. The front face carries an IP40 protection class, so it's protected against tools and wires >1 mm but not against water ingress; keep it inside a sealed enclosure for washdown areas.
Panel integration notes
Mounts on a standard DIN rail or directly to the panel backplate via the four screw holes in the base. The 105 mm width occupies three 35 mm DIN modules. Power loss is rated at 0.5 W maximum — negligible for thermal budgeting inside a sealed enclosure, but the IP40 front means the breaker itself is not sealed; the enclosure must provide the overall IP rating. The breaker accepts optional motor drive (: Yes), so remote tripping or re-closing can be added without changing the frame. No undervoltage release (: No) and no communication function (: No) on this variant — those are separate order codes if needed.