The Siemens 3VA2125-7KQ42-0AA0 is a SENTRON molded case circuit breaker rated for 25 A continuous current across a 4-pole configuration. Its interrupting capacity hits 330 kA at 240 V, dropping to 242 kA at 415 V and 440 V, then to 187 kA at 500 V, and 3.7 kA at 690 V — so the SCCR you plan for depends entirely on your system voltage. Designed for line protection, it includes ground-fault monitoring via summation current formation on L + N conductors, and it supports communication functions for integration into a monitored distribution scheme.
What the ratings mean for your panel
The 25 A continuous rating holds flat across the entire operating temperature range from -25 °C to 70 °C — no derating curve to calculate for ambient heat inside a closed panel. That 330 kA interrupting capacity at 240 V is what you cite for the SCCR label on a 240 V distribution board; at 415 V or 440 V it's still 242 kA, which covers most industrial fault-current scenarios. The 3.7 kA at 690 V is a steep drop — if your system runs at 690 V, this breaker is not your high-fault option. The 4-pole design means it switches all three phases plus neutral, which is standard for TN-S or TT systems where you need neutral isolation.
Panel integration and footprint
Dimensions are 86 mm deep, 140 mm wide, and 181 mm high — a 4-pole MCCB that fits standard distribution panel mounting. The 140 mm width is the key panel-space dimension: it's wider than a 3-pole unit of the same frame, so verify your busbar spacing and enclosure cutout before committing to the layout. Rated insulation voltage is 800 V, and maximum power loss is 0.6 W — negligible heat contribution inside the enclosure.