What this MCCB carries and where it fits
The Siemens 3VA2025-8KQ42-0AA0 is a SENTRON molded case circuit breaker rated for 25 A continuous current across the full ambient range from -25 °C to 70 °C — no derating needed up to 70 °C. Its 4-pole design handles three-phase plus neutral, and the interrupting ratings climb to 440 kA at 240 V, 330 kA at 415 V, and 220 kA at 500 V, so it clears high-fault currents without cascading upstream. The line-protection design includes ground-fault monitoring via summation current formation on L + N, and a communication function for integration into a monitored distribution system.
Panel fit and mounting
The 3VA2025-8KQ42-0AA0 measures 181 mm high, 140 mm wide, and 86 mm deep. It mounts on a DIN rail or can be screw-fixed to a backplate. The 4-pole footprint matches standard SENTRON 3VA panel cutouts; verify busbar spacing if replacing an older 3-pole + neutral block arrangement.