06-12-2018 12:35 PM
My own expereince with repaired VR3's has been very poor, and they are an older design, so parts is an issue.
I have successfully retrofited a number of multiple unit paralleled systems with Basler AVC63-12A1 regulators, these are essentially the same AVR is the VR6, but available in 120VAC sensing.
If you are doing VAR share in voltage droop or in cross current you will likely need to replace the CAT droop transformer with a properly sized 5 amp secondary droop CT. But in doing that I think you will find your VAR share performance will improve if properly setup and tuned.
If you are using some kind of an active VAR share controller in your parallel system, I think you will find the AVC63-12 to be more capable of dealing with remote voltage bias signals. It was a weakness in the VR3 for many applications, with the voltage adjust input being a common failure point.
Hope that helps, MikeL.
06-12-2018 09:08 AM
Does anyone have an outlet of sourcing 120V VR3's (used but functional)? Or a contact that has a good reputation of repairing malfunctioned VR3's?
While retrofitting VR3's is the obvious option, in this case the amount of paralleled units at this specific site makes this retrofit quite expensive. You can lead a horse to water, but you can't make it drink. Let me know everyone's thoughts.