"voltage relay" instead of RCD ?

[Stu435]

So I'm getting my flat in Kyiv (don't ask...) done up.

I'm using quite experienced builders who have their own tradesmen. Now when it came to electrics I had two main questions: 1/ sizes of the cables on each circuit and 2/ Would there be at least one RCD in use ?

For part 2, he came back and said "RCDs are not very common - we use voltage relays". My search in Ukranian reveals that I think he means this sort of thing:

https://rozetka.com.ua/ua/rele-4673183/c4673183/producer=schneider-electric;tip-247448=rele-napryageniya/

Is this just a breaker of some sort? I see in their electrical merchants they do have main RCDs but I couldn't find any RCBO

I wonder if I should insist he uses at least 1 RCD per CU (flat is on 2 floors and is getting split into 2 flats). But I feel I'd rather know what that "voltage relay" is doing first - if its just keeping the voltage around 230V and isn't for safety then presumably I should insist ?

 

[James]

Looks like it switches the supply off if the voltage coming in goes to high or to low.

 

[brianmoooore]

"Voltage relays" were common in the UK for earth leakage protection in the UK when I started. Connects between the earth bar and the earth rod (or mains water pipe in practice).
Perhaps they're still used over there?