My mains supply here is 230Vrms and the ADE7880 is reporting this correctly.
When I switch on am appliance with a motor such as a hairdryer or vacuum cleaner the Vrms reported by the ADE7880 drops down to around 150-180V however a multimeter will still measure the mains are 220-230 Vrms.
Is this to be expected? Any idea what could be causing the ADE7880 to report such a low Vrms compared to a multimeter.
Here are some waveforms exported from the ADE7880. Apologies but I'm not using the high speed data port so the sampling rate is a bit low.
With mainly resistive loads - peak instantaneous voltage around 310V.
With hairdryer on - peak instantaneous voltage now around 220V with what looks like some form of clipping?
Vacuum cleaner - similar to hairdryer.