The Siemens SENTRON 3VA1225-1AA42-0AF0 is a 4-pole switch disconnector built in an MCCB-style frame (IEC frame 250). It's rated for 250 A continuous at 40 °C and holds that rating all the way up to 50 °C — no derating needed in a typical warm panel. At 55 °C it still carries 243 A, and at 70 °C it's good for 223 A (–). That derating curve means you can push this into a hot enclosure without oversizing.
What this disconnect does — and doesn't do
This is a straight switch disconnector — no overload protection, no short-circuit protection. It's meant for isolating a circuit under load, not for protecting it. The main circuit connects via busbar connection with front terminals, so you're looking at a solid copper bar drop, not wire lugs. It ships with a nut keeper kit. The auxiliary contact block carries 1 auxiliary switch HQ plus 1 trip alarm switch HQ, giving you two CO contacts total. That's enough to signal position back to a PLC or light a panel indicator. No undervoltage release, no communication function. It's a bare-bones disconnect — reliable, simple, and built for the long haul with a mechanical life of 15,000 operating cycles.
Panel fit and environment
Footprint is 70 mm deep, 140 mm wide, 158 mm tall (–). That's a four-pole unit taking up about five and a half inches of DIN-rail width. Front IP40 protection keeps tools and fingers out but isn't rated for washdown — keep this inside a closed panel. Operating range is -25 °C to 70 °C, storage from -40 °C to 80 °C (–). Maximum power loss is 57 W, so factor that into your enclosure heat budget.