Current Transformer- SCT-013-030

I recently purchased the above current transformer from Sparkfun and the unit is working properly.

I have an arduino running the Open Energy code but I am getting current measurements even when the CT is not connected.(I thought the digital filtering was suppose to take of this??)

If I connect the CT and calibrate the arduino say when having a load of 20Amps, the unit does not seem to detect very light load like 100W whereas  it can be detected by multimeter.


Amin Zayani's picture

Re: Current Transformer- SCT-013-030



I had the same problem. I fixed it by connecting the other unused analog inputs on my arduino to ground (with a large resistor). That will delete the interferences that other alanlog inputs cause to your current input.


Try that and tell us how it works out for you!




Guest's picture

Re: Current Transformer- SCT-013-030

Thank Amin,
I did that and the unit is now responding properly by giving the correct values.
However am getting negative real power values!

glyn.hudson's picture

Re: Current Transformer- SCT-013-030

Try clipping on the CT sensor the other way! Or swap round the connections to the CT. This should sort it


ggkinuthia's picture

Re: Current Transformer- SCT-013-030

Thanks Glyn,

The uno is running perfectly!


Good day.


Sergegsx's picture

Re: Current Transformer- SCT-013-030

Is this a common practice? to connect unused analog pins to ground using a big resistor?

I believe my setup is running correctly but maybe its something i should think about adding or at least know.

So is it recommended in all cases?


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