I asked the engineer who designed this to cast an eye over that breakout board. Here’s what came back…
The more I think of that ADE9000 breakout board the more it disturbs me. Looking at the photo, the 1Mohm resistors look like 0603 size (1.6x0.8mm). They typically have a working voltage rating of 75V and a maximum overload of 150V. In their design that is a single component that has 375V peak across it. On top of that the spacing on the PCB is a serious concern. For 230V stuff it is common to have 1.5mm between traces after some sort of protection (ie a fuse). For the traces before a fuse or other protection you would double that to 3mm.
For 415V you would double that again. That is why our monitor has larger connectors for the V and big spacing and 4 resistors in series for the voltage divider. For safety testing the inspector is allowed to short out any single component and in doing so the design must not catch fire or present a safety risk.
Also, for reinforced insulation up to 300V you need at least 6.4mm of clearance. Each 0603 resistor gives you approx 0.8mm clearance between the copper pads. Again that is 230VAC across 0.8mm Not much security at all. In our monitor I have four big resistors (1206 I think). They each have a higher voltage rating due to size (200V) and the pads have a 2mm separation giving me 8mm in total - the same as the isolation gap between safe and high voltage sides in other parts of the board.
The 5mm connectors they are using also don’t have the voltage rating or physical clearance for 415V 3-phase. They are rated and have clearance for 230V (ie less than 300V working voltage), but for 3-phase you need 7.5mm connectors and appropriate spacing between pads on the PCB.
I sure hope no-one gets hurt from this design.