Can the PQube 3 be connected directly to 1000VAC?

690V refers to the nominal and is used as a commercial spec. 0-750VAC (L-N) and 0-1300VAC (L-L) is the measuring range.

To connect to a 1000VAC (L-N) nominal system, the answer would be 'no' because the maximum range is 750VAC L-N. But if it is 1000VAC L-L (or 600VAC L-N nominal), technically this will work.