Can we use VPL12N VarPlus Logic Power Factor controller in 690V system?
Yes, VPL can be used 690V AC System also.
For voltages greater than 480V(L-L), you can use a voltage transformer. Referring to the wiring diagram given in the manual, you can use voltage transformer (690/400V). Further, you need to do following configuration in the controller:
Set 201 as 690V, set 203 ( VT factor) as 1.7 (690/400), so the controller will read voltage correctly.