No mains level measurement click boards available?

I suspect the small size of the Click board form factor makes it hard to achieve the required high-voltage to low-voltage isolation necessary to ensure safety. Usually high-voltages devices aren't made "in-the-open" and marketing them as such may open the creators up to some responsibility if someone were to come to harm.

If accuracy can be sacrificed, then a transformer isolation would be safest as there's actual insulation separating primary and secondary. But every transformer will have its own magnetic hysteresis errors and the like to deal with.

If the currents are large enough, especially if they're AC, current transformers or hall-effect sensor current clamps might be the better way to do current measurement. But they're not ideal for low currents ...

Resistive dividers may be fine for a while, but this is contingent on respecting the resistor's maximum voltage over worst-case spikes in the input (which is why some surge protection in the form of some MOV/GDT might be advisable). Ordinary "small" 0.25W resistors may only have an operating voltage about 200V. Using higher-rated resistors would be advised if you want to go this route. But some simple issues can make your circuit "dangerous" - e.g. if contact with the circuit is made and there are implicit assumptions about it being connected the right way around (with respect to live and neutral) depending on the plug used in your country.

Assuming you understand the caveats, I suppose one could always design and build their own "oversized" Click board ...

- Gough

yes - some cases can be worked-around using existing parts (with varying hazard level)... What I personally find strange is - for example - earlier mentioned advanced power meter chipset (with four-quadrant measurement), but limited to 50V...

Maybe it is also because of regulations. MikroE is Serbia based company and I am not sure if Serbia (or any other Europe country) law allows selling non-completly-insulated mains devices to non-qualified technicians (or even to anybody).

that may be it - but some boards have  electrical hazard markings (and are limited to 85V - which is considered above safe voltage level). In any way - inconvinient while considering repurposing depreciated stuff :)

For the Click you mentioned - https://www.mikroe.com/pwr-meter-click it would seem the chip is capable.

https://download.mikroe.com/documents/add-on-boards/click/pwr-meter/pwr-meter-click-schematic-v100.pdf

Seems like the resistances are arranged in series (R11-R13) to improve voltage rating, but they're a bit small compared to the typical application in the Microchip datasheet.

https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/MCP39F511A-Data-Sheet-20006044A.pdf

Perhaps this is the reason the design isn't intended to handle 50V+ but also, I'd hazard to say, the spacing is still quite narrow especially for mains power. Even if you do get the resistors right, the lack of clearance could be problematic.

Well there is also this one:

https://www.mikroe.com/pwr-meter-3-click

Hall for the current, resistive divider for the voltage. I suspect you can get away with higher voltages by changing resistances, but the footprints are probably not ideal for higher voltage resistors.

- Gough

yes - this is the fact I was originally upset: reference design has 1000:1 voltage divider and this click board is configured as 100:1. It really may be mainly safety issue