Switch Disconnector for Isolation and Safety Switching
It is built on the 3VA1 IEC frame 160 platform and is intended for isolation and safety disconnection of circuits where overload or short-circuit protection is handled by upstream devices. With a rated insulation voltage of 800 V and maximum operational voltages of 690 V AC and 600 V DC, this disconnector is suited for 400 V and 480 V distribution panels as well as DC bus applications. The front-terminal busbar connection simplifies panel wiring, and the IP40 front protection is adequate for enclosed switchboard installation where the front face is behind a door.
For a 125 A feeder, this part provides a direct match; for lower-current circuits, it offers headroom but occupies the same panel space as a 125 A device. The undervoltage release (UVR) is wired separately from the main circuit; its 120-127 V AC coil must be continuously energized for the disconnector to remain closed. This is a common configuration for safety circuits where loss of control voltage must open the main contacts.
The front-terminal busbar connection accepts busbar fingers or cable lugs; the busbar system must be rated for the 125 A continuous current. Maximum power loss is 38 W, which should be factored into enclosure thermal calculations.