it work for a month ago, but today I will use it but is showing negative value.
how do i change it
(it is a plug and it have been on for 6 hours now)
Did you change to a different receptacle? I know that I changed receptacles once (split phase in US) and it changed the polarity of the voltage reference, that changed the power from positive to negative for my application.
just removed it from one outlet to another. But this morning it seems to work as it should.
hmm strange…