CT Sensors with EmonTx V3 Showing Incorrect Data

I am currently having difficulty with receiving correct data with CT sensors on emoncms. I am monitoring the power of 4 different pumps. I clipped CT sensors over each individual hot and am getting values on emoncms, but one or more of these values are wrong. On channels 2-4 of the emonTX I believe I am getting accurate data, but channel one says a pump is drawing 100W of power. However, I used a multimeter and found 4.5 amps was running through that wire at about 115V which would be approx 520W. Since this value was off by a fair amount I clipped two CT sensors to the same wire on another pump to see if they would record the same value. One recorded a value of about 900W while another recorded 700W. Shouldn't they be the same? How come I am getting different values for two sensors on the same wire?

-Nate

Robert Wall's picture

Re: CT Sensors with EmonTx V3 Showing Incorrect Data

Yes, they should read sensibly the same. Have you read the FAQ - there are some hints there.

Does the fault stay with the channel or follow the CT if you swap them around?

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