"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?

 

[newfutile]

I don't think it's for earth leakage it appears to be to interrupt the power if it gets too high or low,I would try to get a proper rcd as well as that device

 

[mainline]

Easy9 series voltage control relay EZ9C1240 by Schneider Electric is designed to protect different kinds of electric devices against overvoltage and undervoltage.
Relay can be used in single-phase circuit with voltage 230VAC and load no more than 40A. In case voltage surges up to 265V or drops down to 160V the relay switches off all the consumer devices. When voltage goes back to its normal operational mode relay automatically switches on the load in 25...35 seconds.

 

[James]

"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?

are you thinking of A voltage-operated ELCB?
that is not the device listed above.

 

[brianmoooore]

Quote from the OP: "RCDs are not very common - we use voltage relays". An under/over voltage trip is not a substitute in any way for a RCD, but an old VO ELCB does perform some RCD functions, so that's what I thought it would probably be.
Having looked at the link in more (translated) detail, I see that a voltage trip it is.