120V/240V split phase voltage reference

This isn’t the best way to address your accuracy problem. IoTaWatt is always much more accurate than you are reporting and these things ALWAYS end up being a configuration issue. I’m willing to try to resolve this but as I said in another thread, I don’t have a context to understand your setup, so I asked for some simple information as a starting point.

https://community.iotawatt.com/t/checking-accuracy/4503/6?u=overeasy