Nerdy smart switch feature

It is unlikely that the mains voltage will remain rock stable at any given time Certainly turning on the microwave in my old house would dim the lights...and indeed in this one when the normal supply was replaced by a container sized generator.

Volts drop?

Possibly the accuracy may only be 2% and that may depend on the purity of the sine wave or if it's a true rms reading. Having 2 decimal places is a bit meaningless.

However, even if the reading is 2% high for 220V it will be 2% high for

probably an 8bit ADC, scaled so that slightly north of 240V+10% reads 255?

It will vary with the distance back to CU along your circuit, and the current draw from things on that circuit

Oh I wasn't expecting it to be rock solid - the load on teh grid will affect it for a start.

But sometimes even if it's not accurate it's relative readings might prove interesting.

I wonder what a million readings like that from all over the grid could do ?

Report Voltage

Report Voltage

Report Voltage

Report Voltage

Indeed. Sometimes total accuracy isn't so vital if you are comparing readings from the same inaccurate system ....

I've reflashed some of those £10 Tuya smart switches with Tasmota:

Maxcio Module PowerSkt6369 Voltage 257 V Current 0.207 A Power 45 W Apparent Power 53 VA Reactive Power 29 VAr Power Factor 0.84 Energy Today 0.696 kWh Energy Yesterday 1.089 kWh Energy Total 51.988 kWh ON

and I can press the butt Maxcio Module powerskt1158 Voltage 241 V Current 0.172 A Power 1 W Apparent Power 42 VA Reactive Power 42 VAr Power Factor 0.02 Energy Today 0.014 kWh Energy Yesterday 0.022 kWh Energy Total 190.886 kWh ON

so I suspect the voltage measurement isn't super accurate. They use different power monitor chips so different brands may be better or worse.

Theo

Take up a lot of online storage to no good effect. They know already what they need to know...