earthing systems abroad

[dekachad]

Hi all.
I have searched the forum and there is alot of different answers to different situations, which confuses me. So, I will put my situation on here.
I live in rural
Bulgaria and just about to do the re-wire. Everything will be wired up as normal uk spec except using radials and not rings. The bit where I am confused is the earthing arrangement. There is only L and N coming into the house (which needs upgrading). I have found out that this is a pme neutral, it is earthed at every overhead pole. I asked a local electrician what the Bg specs were and he said just put a link from the earth pin to the neutral pin in every socket and switch ! no other earth. I couldnt get my head round this. So I am thinking to connect earth to the neutral on the supply side of the cu, drive an earth rod in and also connect to the copper pipes that supply the water in the house (the water mains are all galv steel). Does this sound right or am I off the mark here.?
Thanks.

 

[dekachad]

sorry, forgot to say the cu is a 17th ed one with circuits protected by dual rcd's

 

[Farmelectrics]

Not herd of linking nuetral and earth at sockets before I would drive some rods down myself

 

[Engineer54]

Never link N-E at every socket, as has been suggested by the local electrician, end of!! lol!!!

If what your saying is correct, and that an earth rod has been linked to the Neutral conductor at every overhead pole then connect at the service head as you would back in the UK using an external Henly block as the N-E link and MET or the like, don't use the CU's earth and neutral bars. Yes it's prudent to drive in a local earth rod, to connect to the installs MET, try and get the Ra as low as possible in this instance, 200 ohms isn't going to do it!! Hopefully they don't use 1 m X 3/8'' rods over there but extendible 5/8'' rods. Check your Ze etc to make sure that you do have a solid PME supply connection.

 

[dagrat]

As above, but would suggest you make absolutely sure of the relevant earthing arrangement by getting in touch with the local dno.
As Eng 54 says never link earth and neutral at fittings, run cpc,s within wiring, and never rely on local electrician.

 

[Deleted member 26818]

What the local electrician is proposing would make the neutral conductor into a PEN (combined Earth and Neutral) conductor, making the installation TN-C.
This is something that BS7671 prohibits, although it is allowed in many (especially Eastern European) countries.
One of the reasons why this is prohibited by BS7671, is that if there is any loss of neutral in the installation, there will also be a loss of earthing.
Another reason, is that RCDs will not operate, untill something or someone provides an alternate earth fault path in the event of an earth fault.
One other reason, is that if polarity is reversed in any part of the installation, a single pole device would disconnect the earthing.

I would make the earth to neutral link at or before the board as you suggest.
Install an earth electrode, but use an oversized Main Earth Conductor to allow for your earth conductor to become the neutral return path in the event of a distribution neutral failure.

 

[dekachad]

Thanks for everyones replies. Spinlondon- I have done all that today, but not tested yet.
One more thing, I have a cast iron wood burner that runs the central heating, all the piping is in copper. The piping obviously all runs back to the outlets on the stove, which sits on a stone floor, and this floor is about 4ft below ground level. Do I need to bond this lot.?
Thanks

 

[Deleted member 26818]

No you don't need to bond it

 

[dekachad]

Thanks again. Will do Ze test later today. Got sort the boiler circuit tripping both rcd's first. Hopefully just a misplaced neutral as was rushing in the dark to get the power back on ( I know, I know)!
Domestic earthing rods are unheard of here, as are MET's and you would have to buy a black or white single core cable to use as your earth cable. Luckily I bought mine over with us and when I run out of anything, I lend from my mate who is still to-ing and fro-ing.
I went down the local dno yesterday and tried to explain I need to uprate the tails (only 6mm) and I cannot disconnect the supply from their mains. I need to do this so as they dont see all the earths in the cu, because apparently they will disconnect the supply untill it is done to their specs. Which is no earth and the earth pins looped to the neutral pins in the circuits. Another quirk they have is having lights and sockets on the same circuits and done thru a small circular jb bedded in the walls, and they run the shortest route, sometimes going straight across a window.? You have to be very careful chasing out.! Uk health and safety would love it here, Lol.
The dno said they would switch the power off to the village for £8 and ring them to put it back on when I finish, the locals would love me for that.!!! Especially if I can't get the 16mm tails thru the bent metal rod to the supply, then have to travel to the city to find some 10mm, could be off for 2 days.

 

[Deleted member 26818]

Yes the JBs in the walls threw me when I first came across them.
They also seem to like fixing connector strip to joists, rather than using JBs or enclosures above ceilings?

 

[Geordie Spark]

Is this what is known as an Exported Earth? :biggrinjester:

 

[dekachad]

Test reults. Ze=0.65 Zs=0.62 Ze on the earth rod I installed=29.9.
Tested the rcds and everthing is fine.
I know the Ze test is high but "this is Bulgaria my friend" as the locals say.
Thanks again.

 

[Engineer54]

Test reults. Ze=0.65 Zs=0.62 Ze on the earth rod I installed=29.9.
Tested the rcds and everthing is fine.
I know the Ze test is high but "this is Bulgaria my friend" as the locals say.
Thanks again.

I'm just wondering now, what they used as earth electrodes at (as you say) every pole?? Can't be much, if your getting values like that!! lol!!

 

[dekachad]

I watched them put the poles in last year. Its a metal bar, probably 5cmx1cm but it only goes to the bottom of the pole, buried about a meter or so. This is why I was concerned and because we dont get much rain. Our pole is probably one the best in the village, as the waste from the distillery sometimes overflows by it.!!!

 

[Elmer BeFuddled]

I watched them put the poles in last year. Its a metal bar, probably 5cmx1cm

Bloody hell! thats short n fat/short n thin!!

...as the waste from the distillery sometimes overflows by it.!!!

Hic!! Any chansh of a holsh? :33: