I have an issue with one of my installations where the readings are incorrect. I.e. a 1200W non modulating heater is showing a consumption of 760W. This is true for most of the CT sensors (24 in total) across 6 EmonTX units. In most cases the readings are out by a fixed factor and these have been corrected by applying a multiplier in the dashboard. However, for some of the CT clamps the factor is variable (e.g. x 1.7 - 2.2). I have tried different CT clamps and changing the ports, however this has not had any effect.
Have you carried out the calibration procedure?
No, as in the past they have worked fine out of the box without the need for calibration. What is the calibration procedure, can this be undertaken remotely?
The procedure is in Resources > Building Blocks. You cannot do the full procedure remotely, but you can of course alter the scale factor as you have done already.
But if one input is varying over time, then it points to a hardware problem. Are you reading apparent power or real power? Without knowing what your installations look like in detail, I can’t really advise you properly.