The Siemens SENTRON 3VA1225-1AA42-0AE0 is a 4-pole switch disconnector in MCCB design rated for 250 A continuous at 40 °C through 50 °C, with a slight derating curve above that — 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, and 223 A at 70 °C. It is built to IEC 81346-2 (reference code Q) and carries a 690 V AC / 600 V DC insulation voltage of 800 V. The front face is IP40, so it's splash-protected against tools and fingers but not washdown — suitable for dry indoor panel environments. It's designed for isolation and safe disconnection under load, not for circuit protection. The 15 000 mechanical operating cycles typical service life reflects a robust mechanism for frequent switching in a panel.
The disconnector measures 70 mm deep, 140 mm wide, and 158 mm high. Main circuit connections are busbar-type on the front terminals. The design accepts up to 4 auxiliary switches (HQ type) and an optional motor drive.