Appears to be no earth

[JackTheCat]

hello,
Just been to look at a rewire, electrics are so old its unreal, thats not the question though...
The supply side is very new and updated, its a TNCS earthing system, but there is no earth coming out of the neutral from the supply, in fact no earth in sight whatsoever, anybody know why this could be?

 

[plugwash]

i'm guessing the REC put in a new head and declared the installation PME capable (and put in the warning notices) but couldn't find any appropriate earth system to connect to (PME earth+inadequate bonding=pretty damn unsafe)

are you doing this rewire? can you post a picture of the area round the meter and service head?

 

[JackTheCat]

plug, that sounds about right, there is no earth at all to attach to, so what happens if i do rewire, do i get in touch with rec before i start?

PS, no warning labels anywere

 

[plugwash]

yes best to get in touch with the rec before you connect up the new install.

 

[RF Lighting]

PS, no warning labels anywere

Are you sure it is a PME supply then? Or could it still be a TT supply with a new service head?

But check with the REC to make sure.

 

[JackTheCat]

thanks plug, i only seen it tonight, just gonna right a quote up in a minute.
I should have took a few photos even for nostalgia sakes, i swear to god its the oldest fuse box i have ever seen

 

[JackTheCat]

RF Lighting
definetely tncs i did checjk

 

[plugwash]

if you are going to do a quote now then remember to cover yourself against the costs involved if the supply turns out to be TT (rod and 100A 100ma time delay RCD)

 

[crystal ball]

I have seen a PME conversion where the REC forgot to connect the earth conductor, several years before

 

[JackTheCat]

Is TT supply always run overhead in suburban areas?

 

[JackTheCat]

anybody?

 

[plugwash]

underground TT supplies do sometimes exist where a TN-S earth has degraded to the point of being unfit for purpose and the supply setup isn't suitable for PME. They also exist in mostly PME setups where a PME earth was deemed unsuitable (petrol stations, some designs of swimming pools etc)

overhead supplies were traditionally TT but are increasingly being upgraded to meet PME requirements.

most new domestic sized supplies whether underground or overhead will be PME.

 

[dingbat]

In Leeds YEDL never connect the earth conductor. Even when I've persuaded them to do it as an emergency service, they've happily converted the cutout to PME but left the actual earth unconnected. Even when I've installed a separate MET and wrapped a 16 sq mm earth conductor round the old service head. Even when I've left a copy of the test schedules and a written request to connect the new earth conductor.

I've come across many installations with modern TN-C-S cutouts with the earth conductor from the MET unconnected for ten years or more, because the householder doesn't know what that bit of green an' yeller from the fusebox is for and the DNO hasn't felt the need to inform.

These days I tell all my customers to let me know as soon as their cutout upgrade has been done, so I can go round and finish the job.

 

[plugwash]

that may be so but you still must check if the supply is certified as PME before connecting your earth to the suppliers neutral (assuming that there are no stickers ETC pointing it out).

 

[dingbat]

Perhaps I wasn't clear.

75% of the properties I see in Leeds have no earth conductor at all.

As a matter of course I report these to YEDL on their emergency line.

In every single case, so far, they have confirmed that PME is available in the area.
In every single case they have come out and converted the cutouts (usually cast-iron enclosures with rewireable fuses).
In every single case they have disconnected the earth conductor to the existing fuseborad/CU and not reconnected it.
In every single case (to date) the customer has not been aware that this is not safe.
In many cases I see jobs where the PME conversion was carried out many years ago, but the earth conductor has remained unconnected.

The importance attached to earthing by the IET is obviously not reflected in the attitudes of at least one distribution network operator.