Earthing from over head lines...

[infinity]

a spark..its a no from me

Thanks anyway Sharon..

 

[jase]

Phone DNO and find out if they are supplying an earth, if not fit Earth rods. Not that difficult is it?

I did that once they didnt know themselves what supply they had in the street i was working in!!! pathetic

 

[Spudnik]

As a general rule, if there are two overhead lines entering a property then the earthing system should be TT.

If the overhead line is single, there is a chance that, even if the installation is still TT, PME could be available, and converted as such.

A phone call to the DNO would confirm the latter, via them doing a site visit.

 

[jase]

Had this about 3 months ago, overhead lines coming into property - 1 cable, just like pme, looking down the street every 3rd or so pole had earth cable coming down it, looking like pme, there was a 16mm earth at the cut out that went inside to the consumer unit, but not connected at either end, there was and old earth stake which was connected, so i'm thinking here we have an old TT installation, that the overhead wiring has been converted to pme but the house has not been, phoned e-on and got directed and re-directed, listened to lots of pretty music whilst "on hold" and the answer??? "we dont actually know what type of wiring we have in that area" !! jesus christ!!! suffice to say even though there could have been a lovely low pme Ze to be had, i left the installation as a TT because at least that way i could confirm the earth arrangement!!


So can sympathise with OP, cause sometimes things aint what they may seem, could be TT could be overhead pme, but obvious lack of any earth would dictate to rod it and TT it, oh and the DNO??? i dont know why people say to call them, next to useless advice in my experience

 

[alarm man]

Thanks anyway Sharon..

only on a weekend mate,im steve through the week.:ninja:

 

[Spudnik]

Had this about 3 months ago, overhead lines coming into property - 1 cable, just like pme, looking down the street every 3rd or so pole had earth cable coming down it, looking like pme, there was a 16mm earth at the cut out that went inside to the consumer unit, but not connected at either end, there was and old earth stake which was connected, so i'm thinking here we have an old TT installation, that the overhead wiring has been converted to pme but the house has not been, phoned e-on and got directed and re-directed, listened to lots of pretty music whilst "on hold" and the answer??? "we dont actually know what type of wiring we have in that area" !! jesus christ!!! suffice to say even though there could have been a lovely low pme Ze to be had, i left the installation as a TT because at least that way i could confirm the earth arrangement!!


So can sympathise with OP, cause sometimes things aint what they may seem, could be TT could be overhead pme, but obvious lack of any earth would dictate to rod it and TT it, oh and the DNO??? i dont know why people say to call them, next to useless advice in my experience

I cant help with the DNO except to say that i havent had any real issues with SSE, however, you can check for PME at the CU if you think its available.

At least that way, you have a case to try and contact someone who knows what they are talking about.

 

[nickblake]

a good majority of the supplies up here are from over head lines and they are mainly TNCS ,occaisionally TT ,this may be a silly question but have you done a Ze , I bet the RCD you are talking about is an old brown one if im not mistaken they were outlawed in a change of the regs back in 1984 or around that time as jason has said contact the DNO for advice

 

[jase]

the OP said there was no earth, how can you do a Ze with no incoming earth??

 

[Knobhead]

Blimey, the arms membership bar has been lowered!

I thought it had been raised, I’m bared!

But that aside, our OP is showing a total ignorance of basic physics. A ELCB with no earth rod?

A 10 year old house with a ELCB? I don’t think so, they weren’t on sale then!

 

[Spudnik]

the OP said there was no earth, how can you do a Ze with no incoming earth??

Do you want to have a think about that for a minute?

 

[Silly Sausage]

I thought it had been raised, I’m bared!

No, definitely lowered Tony.

You're too big to get under it now! :crazy:

 

[Engineer54]

Do you want to have a think about that for a minute?

I've had a think about it, so how Do you get an earth Ze value at the cut-out/CU ?? You can get a neutral Ze, but nothing to compare it with, the installation doesn't even have any services bonding in place....

 

[Engineer54]

a good majority of the supplies up here are from over head lines and they are mainly TNCS ,occaisionally TT ,this may be a silly question but have you done a Ze , I bet the RCD you are talking about is an old brown one if im not mistaken they were outlawed in a change of the regs back in 1984 or around that time as jason has said contact the DNO for advice

I doubt it, they needed an earth connection to work!!

By the way, they aren't outlawed, they just have a recommendation to be changed for a current operated unit. They were never that reliable in general terms, but in certain conditions they worked pretty well, and some are probably working pretty well. The main trouble with them, were that parallel earth voltages set them off...

 

[adben]

Infinity, you had encountered a TT system (same to as we say multi-grounded system from the country I came from). Refer to your Electrician's Guide (updated to 17th ed, Chapter 3, it illustrates clearly the things you want to know.

 

[Spudnik]

I've had a think about it, so how Do you get an earth Ze value at the cut-out/CU ?? You can get a neutral Ze, but nothing to compare it with, the installation doesn't even have any services bonding in place....

If you test between line & earth, this would give you an indication that PME could be available.

 

[WPD Lad]

Where are you based? If you're mids just give WPD a ring and we'll pop out and tell you. Most of our lines are TNC-S, post a pic of the cutout!

 

[Engineer54]

If you test between line & earth, this would give you an indication that PME could be available.

That was the point, there is no earthing available anywhere to test!!

 

[WPD Lad]

That was the point, there is no earthing available anywhere to test!!

Can't rule out PME without seeing the cutout

 

[Engineer54]

Can't rule out PME without seeing the cutout

Don't think i've mentioned ruling out the possibility of a PME connection at the cut-out!!! That can easily be ascertained by contacting the local DNO. Doesn't stop a TT system being installed in the meantime, ...in fact it's a good idea to have another rod on a PME system earth at the installation.

 

[Spudnik]

That was the point, there is no earthing available anywhere to test!!

AAArrggghh!!! I meant line and neutral!!!