What the ratings mean for fit
The 3VA2025-7KP42-0AA0: The 25 A rating holds flat from 40 °C all the way to 70 °C — no derating curve to worry about in a hot panel. That's rare; most breakers start dropping at 50 °C. The 330 kA interrupting capacity at 240 V means it can handle a dead-short on a transformer secondary without the upstream fuse needing to clear. At 690 V it drops to 3 kA, so you're not using this on a 690 V bus unless the fault current is very low. The ETU850 release is a communicating electronic trip unit — it talks to the plant network, so you can pull event logs and set curves remotely. No undervoltage release or ground-fault monitoring built in, but the communication function means you can add those through the system bus. IP40 on the front means it's protected against tools and small wires, but it's not sealed against moisture. Keep it inside a panel, not out on a washdown line.
Panel fit and mounting
Footprint is 140 mm wide by 181 mm tall by 86 mm deep. That 140 mm width is a standard 4-pole MCCB slot — it'll drop into a SENTRON panel base without adapters. The 86 mm depth leaves room behind the door for wiring gutters or a second row of breakers.