This sounds similar to something we experienced. We had a VR3 voltage regulator go bad and it was replaced with the current model, the VR6. (VR3 is obsolete) Worked for a while, then during a utility outage, bad things happened. Our Catepillar dealer feels the VR6 does not "play well" with...
We have a number of installations like this, and although one would like everything to be together, there is certainly nothing wrong with it. Just be sure to run the power and control cables in concrete encased duct bank, for physical protection.