Hi OpenEnergy, first post here.
Before I take my DIY energy monitor to production, I’m running many tests in my bench. I’m using 3-different multimeters + market ac volt/ampere meter.
All good, EXCEPT by the two hair dryers that we have, when in ‘half power mode’ (full mode gave consistent readings on both).
All mathematics seems to be okay, so I believe the error is caused by a heavy distortion in the AC wave. The screenshots are from the Arduino ADC pin, with the hairdryer in full and half-power mode.
I tried different phase corrections between 0 and 2, with no significant change in the results.
Maybe someone already experienced it or could advise?
Arduino Mega (5V VREF)
HWCT004 CT, 50A 50ma 1000 turns
AC 220V 60Hz (Brazil)
ct1.voltage( 3 , 220.0D / 0.803D , 1.0D ); // ADC pin , calibration 270.08 , phase shift
ct1.current( PIN_CT1 , 1000.0D / 22.1D )
ct1.calcVI( 300 , 2000 )
2.42A = ~482W