Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Getting nothing but 11w readings #3

Open
beercity opened this issue Jun 22, 2020 · 3 comments
Open

Getting nothing but 11w readings #3

beercity opened this issue Jun 22, 2020 · 3 comments

Comments

@beercity
Copy link

I just get 11W on the basic test sketch no matter what.
If I connect the CT, I get 11w, if I disconnect I get 11W.
If I remove the Wemos from the sensor board, still 11W

Sometimes I get 23W. But mostly 11W, and never anything besides these two.

Board issue? Code issue? Not sure.

@Mottramlabs
Copy link
Owner

Hi beercity
I'm assuming you are using the basic test sketch and the 11 is in fact 0.11 Amps. That is the softwares quiescent value (which can be trimmed to zero in the code). Anyway this is what you would see if there is no current flow through the CT or it's not plugged in. You can check the signal from the CT with a multimeter set to AC volts connected across R1 the 22R burned resistor, typical values would be 169mV AC when a load of around 4.5A is present, only approximate value without calibration.
Don't forget that the CT should be clamped across only one of the wires under test, either L or N but not both as this cancels out the signal.
David

@sw1970
Copy link

sw1970 commented Mar 13, 2021

Hi Mottramlabs, when you say "can be trimmed to zero in the code", do you simply mean subtract the quiescent value from the measured amount? Thanks!

@Mottramlabs
Copy link
Owner

Hi sw1970
Yes you are correct, simply subract the quiescent value from the sensor. Simple way is to remove the CT from the wire under test.
David

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

3 participants