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. This is a pure disconnector — no overload or short-circuit protection (no trip indicator, no undervoltage release, no voltage trigger). 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.
Integration & Mounting
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. Power loss is 57 W maximum at rated current — factor that into enclosure thermal calculations, especially in a crowded panel.