That means you can install it in a warm enclosure or next to heat-generating gear without recalculating the load schedule. The 690 V AC (50/60 Hz) and 600 V DC maximum operational voltages cover most industrial supply voltages, including 480Y/277 V and 600 V delta systems common in North American panels, as well as 400 V and 690 V IEC distribution. If you need auxiliary signalling or undervoltage protection, you would look at a different configuration within the 3VA1 family.
This disconnect connects via busbar to the main current circuit, with front terminals for incoming and outgoing conductors. The 101.6 mm width (4-inch, 4-module DIN footprint) matches standard 4-pole MCCB cutouts. Depth is 70 mm, height 130 mm — it fits most distribution panelboards without crowding the gland plate.