The Siemens 3VA2025-6HN42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 25 A continuous current across a 4-pole configuration. It uses the ETU350 electronic trip unit, which gives you adjustable long-time, short-time, and instantaneous protection curves — useful for coordinating downstream feeders in a distribution panel. The interrupting capacity hits 242 kA at 240 V, so it handles high-fault-current scenarios without cascading upstream.
What the ratings mean for fit
The 25 A continuous rating holds flat from 40 °C through 70 °C ambient — no derating needed in a warm enclosure, which simplifies panel design. The 242 kA interrupting capacity at 240 V is the headline number; at 415 V it still delivers 187 kA, and at 690 V it drops to 3 kA. For a 480 V system (common in North American industrial plants), the 121 kA at 500 V gives you a realistic SCCR benchmark for coordination studies. The ETU350 trip unit is a line-protection design — no ground-fault monitoring, no communication module, no undervoltage release built in. That keeps the BOM simple for a feeder breaker, but if you need those functions, you'd step up to a 3VA2 with a different option code. The IP40 front protection means it's fine for a clean indoor panel; not rated for washdown or outdoor exposure.
Panel integration
The 3VA2025-6HN42-0AA0 measures 181 mm high, 140 mm wide, and 86 mm deep. It mounts on a DIN rail or directly to a backplate with the standard screw-mount kit. The 4-pole footprint fits a 70 mm wide cutout in a typical panel layout — check your gland plate clearance for the line and load lugs. The ETU350 is powered internally from the line-side current, so no auxiliary supply needed.