Roger,
Just out of curiousity, can I ask why your trying to correct the phase converters power factor? Is it because you're being penalized by the POCO for low power factor or are you trying to free up system capacity?
Years ago we used a portable meter that was about the size of an old analog meggar to measure power factor. Now we use the multi-function ct. analyzers like the ones Dranetz or several other manufactureres make. These will also allow you to trend power factor on feeders etc.
You might ask your POCO if they will help you with this.
