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boblemaire / IoTaWatt

IoTaWatt Open WiFi Electric Energy Monitor
https://iotawatt.com
GNU General Public License v3.0
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Feature request enter ref voltage manually #251

Closed i00 closed 4 years ago

i00 commented 4 years ago

The voltage at my house varies between 243 - 245 (been using IoTaWatt for about a week) ... I don't really think that you should have to have a separate ref transformer for this ... I think there should be a way to enter the value manually - if you have a good supply it should vary very little anyway!

ogiewon commented 4 years ago

I believe, in addition to voltage, the phase angle of the AC waveform is being measured and is critical to accurate power measurement of all of the CT inputs.

boblemaire commented 4 years ago

@ogiewon right. While you may think your voltage is only varying between 243 and 245, it is actrually varying between -345 and +345 every 20ms in a sine wave. IoTaWatt measures this about 700 times during that 20ms along with the current at that time. These 700 measurements are used to developp real power - what you pay for. There are energy monitors that only measure the current and multiple by a constant nominal voltage. What they report is apparent power which is typically greater than real power. I'm closing this out.