I tested the EmonTX V3 prior to installing the CT in the electrical distribution box and it was reporting 0W when there was no power going through the test circuit. Now at least one CT is reporting 28W (approximately as it varies between 24 and 30) even when the circuit breaker for that circuit is open. I assume it is some sort of cross talk or induction from another nearby circuit, even though there is only 1200W or so going through the whole of the distribution board at the time.
Is this a common problem with CT sensors?
If it is cross talk then I assume that the error goes up with consumption in the nearby circuits?
Do people worry about this level of error or is it just accepted as near enough?
Re: EmonTX via CT reporting 28W when it should be zero
The CT may well be picking up the field from the adjacent conductor. It's inevitable, from the very nature of the beast. Increasing the spacing and changing the orientation (assuming it's possible to do either) could make a significant improvement. I did some measurements and those are in the report for the YHDC CT. 28 W represents only a little more than 0.1% of the maximum reading.
Re: EmonTX via CT reporting 28W when it should be zero
Thanks