Interesting problem, need some help - resolved

I have a 220v circuit configured with 1 CT on a single leg:

I have an output configured as: ‘unaccounted’ = “house mains” - “everything measured”


When I plot things, I see:

which gives me a negative value of 1/2 the total power used.

What am I doing wrong?



A dryer usually draws about 5kW. Yours is coming in at 10kW, so I think it’s overstated. Are you sure theCT is only on one wire? It looks as if you may be using the technique of passing both wires through in opposite directions, which would be the right way to measure a dryer because usually the tumbler motor is 120V and only on one leg.

Can you double check that CT? If there is any question, a picture would help. If you find that it is as I suspect with both conductors through the CT, you only need to uncheck double to fix this.

Yep, thanks, got it confused with the rat’s nest that is my box!