What this MCCB is and what it does
The Siemens 3VA2025-8HN42-0AA0 is a 4-pole SENTRON molded case circuit breaker (MCCB) rated for 25 A continuous current across the full ambient range from 40 °C to 70 °C — no derating needed up to the maximum operating temperature. It carries the ETU350 electronic trip unit, which provides adjustable overload and short-circuit protection curves for line protection duty in distribution panels.
Breaking capacity — what the ratings mean for fault clearing
This MCCB delivers 440 kA breaking capacity at 240 V, 330 kA at 415 V and 440 V, 220 kA at 500 V, and 52.5 kA at 690 V. Those are the maximum fault currents the breaker can safely interrupt at each voltage level — critical for selectivity studies and SCCR compliance in the panel. The 440 kA figure at 240 V is exceptionally high, making this unit suitable for high-fault-capacity locations like transformer secondaries or large motor control centers.
Physical fit and panel integration
The 3VA2025-8HN42-0AA0 measures 86 mm deep, 140 mm wide, and 181 mm tall. It mounts into a standard MCCB cutout or on a mounting plate within the enclosure. The front face carries IP40 protection — suitable for general indoor panel environments where tools or fingers won't contact live parts. The N-conductor protection is adjustable between OFF and 100%, giving flexibility for 3- or 4-pole distribution schemes.