Hi, I have the DROK 80-300V 100A panel meter seen here. The displayed kWh does not seem to be accurate. When I divide the difference in two readings by the length of time in hours between them I expect to get the average wattage of the load. Instead I get a larger than expected value by about 5%. The observed wattage reading is fairly constant over time and is about 5% *smaller* than the displayed (kWh difference) / (hours of time). That’s quite a big difference, I think. It actually appears to be = (power factor ^2) x (kWh difference) / (hours of time). Any idea what’s going on? I’d like an accurate kWh reading and not sure how to get it with this meter.

This is for a residential 240V single-phase load of about 3500W and 14.5A. Thanks!