About 4 years ago I bought a Fuji FRN025G11 VFD on EBay new in the box. I wanted a quiet phase converter so I purchased a DV/DT filter out of a Liebert UPS. I added a DC choke and additional capacitors in the DC circuit and it worked great until now. I have run Hurco and Centroid machines as well as manual lathes. Everything was great. I purchased a Kitamura with a 15M control and hooked it up. More times than not when the spindle shuts down during a tool change or just manual operation the VFD shuts down. It throws a OV3 alarm, meaning high DC voltage during running. I tried running the lathe to absorb some of the counter EMF if that was the problem.. I can add braking circuit fo a couple thousand dollars, but I do not think that is th real problem. Looking for ideas. Put your thinking caps on and thanks for any input.