The Siemens 3VA1225-1AA42-0KB0 is a 4-pole switch disconnector from the 3VA1 series, rated at 250 A continuous current on an IEC frame 250. It comes without integral overload or short-circuit protection — it is a disconnect switch, not a breaker — and includes a shunt trip release wired for 208-277 V AC 50/60 Hz or 220-250 V DC, plus two auxiliary changeover switches. The nut keeper kit is included for panel mounting.
What the Ratings Mean for Fit
The 250 A continuous rating (In) governs the main circuit capacity — sized for a 250 A feeder or downstream distribution, not for motor starting duty where overload protection is required separately. The shunt trip release operates on either 208-277 V AC or 220-250 V DC, so it can be wired into a remote trip circuit from a safety relay or emergency-stop chain without an intermediate relay. The two auxiliary changeover switches provide status feedback (open/closed) to a PLC or indication lamp, each rated for the control voltage in use.
Deployment Context
Mounts on a DIN rail or panel plate inside an industrial enclosure. The 4-pole configuration suits three-phase plus neutral disconnection, common in distribution panels for machine tools or process lines where a visible-break disconnect is required for lockout/tagout. The shunt trip allows remote opening from a safety circuit, eliminating the need for a separate contactor in many applications.