The Siemens SENTRON 3VA2125-7KP42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 25 A continuous current, built around the ETU850 electronic trip unit. It is a current-production part designed for line protection in distribution panels.
What the ratings mean for fit
The 25 A continuous rating is the breaker's thermal current. The ETU850 electronic trip unit lets you set the long-time pickup anywhere from 38 A to 300 A. Rated insulation voltage is 800 V, so it's suitable for 480/277 V and 600 V systems with margin. The IP40 protection on the front means it's protected against solid objects over 1 mm — fine for a dry indoor panel, but not for washdown areas. Operating temperature range is -25 °C to 70 °C, with no derating needed across that span — the 25 A rating holds at every temperature from 40 °C through 70 °C (–).
Panel fit and dimensions
The breaker measures 140 mm wide, 181 mm high, and 86 mm deep. That 86 mm depth is the can depth — it fits standard MCCB mounting footprints in switchboards and panelboards. Four poles means it needs four line-side and four load-side lug connections; the neutral pole is switched, so it's a full 4-pole disconnect for three-phase-plus-neutral systems.