The SENTRON 3VA1340-1AA42-0BA0 is a 400 A, 4-pole switch disconnector on the IEC frame 400, built without overload or short-circuit protection — it's a straight disconnect, not a breaker.
What the 400 A rating means for fit
The 400 A continuous rating on an IEC frame 400 means this disconnector handles the full load current of a large motor or a feeder without derating in a 40 °C ambient. It's sized for the main disconnect on a 250–315 kW motor circuit or a bus coupler in a switchboard. The nut keeper kit on both sides of the main current circuit accepts front-terminal connections — expect M10 or M12 busbar lugs, not cable tails. Verify the lug hole pattern against your existing busbar before committing the BOM line.
Deployment context: panel integration
This mounts in a fixed position within a switchboard or MCC bucket — it's not a DIN-rail snap-on device. The nut keeper kit holds the terminal nuts captive during wiring, which saves time when an electrician is torquing down lugs in a tight enclosure. The undervoltage release coil draws its 24 V DC from the control transformer; if the mill loses the 24 V bus, the disconnector opens immediately. In a rolling mill environment, that's the fail-safe behavior you want for a downstream conveyor or cooling-water pump.