The 3VA2125-8KP42-0AA0: The breaking capacity is rated at 440 kA at 240 V AC, 330 kA at 415 V and 440 V, 220 kA at 500 V, and 52.5 kA at 690 V. That headroom means this breaker can sit at the main or sub-main position in a high-fault installation without cascading upstream — the SCCR is the rating that governs the bus bracing and arc-flash boundary, not the 25 A load rating. Physical footprint is 140 mm wide, 181 mm high, and 86 mm deep — standard for a 4-pole 3VA2 frame, so it drops into existing SENTRON switchboard layouts without re-drilling the mounting plate. The front face carries an IP40 protection class, suitable for enclosed panel mounting where no washdown or dust ingress is expected.
Trip unit and communication
The ETU850 is an electronic trip unit with a communication function and other measurement function enabled — it can report current values and trip events over the integrated bus link, which is useful for a site electrical engineer setting up a selective coordination study or for a commissioning engineer verifying fault levels during FAT. The trip unit supports a rated insulation voltage of 800 V, matching the system voltage in most 690 V industrial networks. The breaker does not include a ground-fault monitoring version, an undervoltage release, or a voltage trigger — those are separate accessories that plug into the 3VA2 accessory slots. If the BOM calls for shunt trip or UVR, order the add-on module alongside this frame.
Thermal profile and operating range
The continuous current rating of 25 A holds across the full operating ambient range from -25 °C to 70 °C — no derating curve to apply for elevated panel temperatures. That is unusual for a thermal-magnetic breaker; the electronic trip compensates electronically, so the 25 A rating is the same at 40 °C and 70 °C. For a furnace controls engineer, this means the breaker does not nuisance-trip when the panel sits near a hot process zone, as long as the ambient stays under 70 °C. Storage temperature range is -40 °C to 80 °C, which covers most warehouse and shipping conditions. Maximum power loss is 0.5 W, negligible for panel thermal budgeting.