Exporting more than importing

Can’t figure out why I am exporting more than importing. Only seeing this at low house consumption.
You can see from screenshots, I’ve standard setup but use is negative. How is this the case.

Do I have noise on the wire? It CT clamp to main fuse box has been extended by 5m to solar and pi.


Welcome, David, to the OEM forum.

It could be. Does the cable run close to other circuits, and how did you extend the c.t’s cable?

It could also be errors in the current transformers themselves. 300 - 400 W is well below the stated accuracy range of our standard c.t., and all c.t’s are inherently inaccurate at low and very low currents - it’s due to the way the magnetics inside the core behave. It’s not impossible to calibrate the standard emonPi to reduce that error, but there’s a risk of increasing the error at high power as a result; and in any case the procedure is quite involved - it means changing values inside the “emon” part of the emonPi, and then reloading the software.

Yes unfortunately it does run along side the power cables into house. Only way to route cable.

It’s extend using cat 6 cable. With CT clamp cable cut at the headphone jack and soldier into a bit of circuit board. Cat 6 cable which is shielded is connected to circuit board I’ve 3 terminal connector the wires connect to. Positive,negative and earth. This then connects opposite end where have a piece of headphone cable that plugs into pi. Also have pi connected to earth.

Only seeing it very low freq. So nothing can do really. Thought ask the question.

I presume you’ve checked the usage of the 3-pole connector on the emonPi?

The plug tip is the “earthy” conductor, but biased at 1.65 V above the Pi’s 0 V rail, the input signal is the plug sleeve; the ring is unused.

If you hadn’t looked, you might like to rethink what you did with the CAT6 cable.