the error in Power Factor was terrible for small currents.
You DO realize that POWER FACTOR is IRRELEVANT for small currents. No commercial company or power utilitity company ever talks about POWER FACTOR for feeders with a small current. It is pointless. The ONLY reason to ever talk about POWER FACTOR is when the current is NOT small, because then the transmission cost to the utility company or the power cost to the customer is
significant. If the current is small, nobody cares and they don't talk about POWER FACTOR. If you know what effects power factor
you already know this.
That being said, I think your post will be very useful to people who are interested in power monitors, however , if you don't mind me saying so, if you are posting to contribute to the knowledge base, your post is missing an important document, which is the
schematic. I know how to connect MAX485s but most people don't and I think that while your post definitely constitutes a contribution, is may be problematic for some without the schematic.