What this SENTRON MCCB carries
The Siemens 3VA2025-7KP46-0AA0 is a SENTRON molded case circuit breaker, 4-pole, rated 25 A continuous with an ETU850 electronic trip unit. It's a line-protection design with communication function, so it can talk to a BMS or PLC for remote monitoring and trip indication — no separate aux contact needed for basic status. Breaking capacity is 330 kA at 240 V AC, dropping to 242 kA at 415 V and 440 V, 187 kA at 500 V, and 3 kA at 690 V. That 330 kA at 240 V is a high-interrupting rating — it handles faults on the secondary side of a large transformer or a high-capacity bus without needing a current-limiting fuse upstream. Rated insulation voltage is 800 V, so it's suitable for 480/277 V and 600 V systems with margin. The front IP40 protection keeps dust out of the trip-unit face; the rest of the breaker is enclosed inside the panel.
Sizing and derating
Continuous current holds at 25 A from 40 °C all the way up to 70 °C ambient — no derating curve to worry about in a warm enclosure. That's unusual; most MCCBs start stepping down above 40 °C. The ETU850 release is adjustable between 38 A and 300 A (the minimum and maximum settings), so this breaker can be dialed to protect a feeder or a downstream panel, not just a fixed load. Power loss is 0.5 W maximum — negligible for thermal budget inside a packed panel.
Mounting and footprint
Dimensions are 86 mm deep, 140 mm wide, 181 mm tall. That's a 4-pole frame in the 3VA2 compact footprint — fits standard panel-mount cutouts for this class. No DIN-rail clip; it bolts to a mounting plate. The 140 mm width is the same across several 3VA2 4-pole variants, so a panel laid out for a 3VA2125-8KQ42-0AA0 will accept this one without re-drilling.