An Old Chestnut Rears It's Head Today.

[Evans Electric]

Unoccupied 1970s house being refurbished , we turn up today to replace board , alter some wiring & rewire kitchen .

Fit new board with just one socket by it in garage for builder's use & discover that the PME earth terminal is not linked to the N in the  DNO head.      Fair dues to the Network who attended in 2 hours ...but as this was in the centre of a row of 8 terraced houses , supplies looping pairs of houses ,,I suggested that the other cut-outs could well be the same ( OK its not my business)   ie ;   someone way back didn't fit the links ...............new houseowner has had a shock as he stripped out kitchen sink unit..between pipes and sinktop............no interest shown in checking them out ... :C

 

[Andy™]

few places up here where the entire estate is TT, but many of the service heads have an earth block on the side not connected to anything. and many with the earth cable into the unused terminal block

 

[Evans Electric]

Yep.. exactly how this one was Andy .    Its from the days when no testing was carried out whatsoever ...( younger sparks may find that strange but true)

So for the last 40 years, this house with it's plastic water incommer has relied on the 6mm bond to the gas for an earth .

 

[ProDave]

The DNO don't always seem bothered.

A recent one I had was "fit a new shower"

Well that bit was okay, but I was not happy with the supply.

All there is, is two rubber / cotton covered cables coming through a hole in the wall into the meter.  Nice new tails from meter to CU.

It's those old tails that worry me. No sign of the supply head (just a single in line DNO fuse) so clearly a shared supply from next door.  I'm concerned the supply may not be adequate to add a new shower. If it does get hot and bothered, it could get hot and bothered next door as well.

I'm awaiting the DNO to inspect in now. The only way I could get them to come and have a look was report is as a "fault" I've told the customer I am not fitting a new shower until the DNO have either upgraded the supply cables, or at least told me they are okay (then the buck won't stop with me)

 

[Evans Electric]

Nice one Dave ...........and how many would just not bother ?  Quite a few I'm afraid.

 

[Blue Duck]

PD, Ukpn consider looped supply as a problem and will replace foc if they can. its more of an issue if the tails are vir (or whatever its called these days) they will replace for under elf n safety again foc.

 

[Evans Electric]

I noticed that they changed the cut-out to their latest version when all that was needed was , remove bottom cover. lift earth block off, fit a bit of bare 16mm cable about 30mm long between earth block & Neutral block & re-assemble.

I'd guess houses were  built or thrown up in the 70s perhaps , wired at full speed I'd guess by contractor on a price... Wylex wooden fuseboard nailed to the brick joint  as are KO boxes,  four circuits only with every ground floor socket spurred off the one above.

Bare earth wires ...so 14th edition is it ?  

EDIT :-     So lesson of the week for younger listeners ...................never assume the earth terminal in the side of a cut-out is actually connected to anything inside the cut-out .    

The networks installers obviously could never be bothered so its down to us to check. 

 

[zimmy]

Last time I looked it was the consumers responsibility regarding earthing.  If the earth lug has come off the lead supply cable the supplier has no need to do anything but say for us/you to make it a TT.  The system in question may have been installed like that (TT) for one reason or another.  It may have been wired as over-head in the past?

However if the supply is PME-TN-C-S and it was connected as such and then there was a problem with the earthing  we would be talking of a different scenario.

The old tails are not replaced under 'Health and Safety' any more than any other wiring is replaced.  To quote it as such is not correct. All down to inspection and testing.

 

[Evans Electric]

Last time I looked it was the consumers responsibility regarding earthing.  If the earth lug has come off the lead supply cable the supplier has no need to do anything but say for us/you to make it a TT.  The system in question may have been installed like that (TT) for one reason or another.  It may have been wired as over-head in the past?

However if the supply is PME-TN-C-S and it was connected as such and then there was a problem with the earthing  we would be talking of a different scenario.

The old tails are not replaced under 'Health and Safety' any more than any other wiring is replaced.  To quote it as such is not correct. All down to inspection and testing.

Some responsibility should be on the energy supplier's shoulders  though Zimmy.     Overhead supplies are virtually non-existant in the city , you can't have a PME supply without an earth terminal .  

There is no lead cable , this is concentric , the earth block protrudes from the plastic cut-out allowing the contractor to connect to it . 

This cut-out was clearly marked  "PME"  ... supply & loop to next door in concentric , 25mm in & 16mm loop ..... PME calls for bonding to be installed so there is a responsibility for them to fit the link to the N .   PME  means the earth terminal is connected to the N ( Or as its now called  ...TN-Combined-S)

What we have here is the original contractor  in the 1970s assuming the terminal was Earth &  connected the main  earth  & the 6mm bonding to it.  I was also told  the previous owner was a Sparks.

How typical of the stupid systems that we inherit in this country ...where commercial /industrial premises have an earth connection  but its the responsibility of the house owner to ensure there is an adequate earth connection in their house .  

How many people actually know that ?    1%     I doubt even that .   People put their trust in the "professionals" who have put an electric supply into the house .......... have wired up the house ....have fitted that gas fire in the proper manner .   

 

[Andy™]

Last time I looked it was the consumers responsibility regarding earthing.  If the earth lug has come off the lead supply cable the supplier has no need to do anything but say for us/you to make it a TT.  The system in question may have been installed like that (TT) for one reason or another.  It may have been wired as over-head in the past?

have a look at ESQCR. DNO do not have to provide an earth, but if they do then they must maintain it

 

[Manator]

Last time I looked it was the consumers responsibility regarding earthing.  If the earth lug has come off the lead supply cable the supplier has no need to do anything but say for us/you to make it a TT.  The system in question may have been installed like that (TT) for one reason or another.  It may have been wired as over-head in the past?

However if the supply is PME-TN-C-S and it was connected as such and then there was a problem with the earthing  we would be talking of a different scenario.

The old tails are not replaced under 'Health and Safety' any more than any other wiring is replaced.  To quote it as such is not correct. All down to inspection and testing.

Hi Zimmy,

I understand what you are saying however a supplied earth must be maintained. Be it TNC-S or TNS. I will not involve PME because I have rarely seen a correct PME installation.

It may not be a health and safety requirement to replace old tails, and you have correctly stated one reason for the change (testing).

All cables have a lifespan, and most DNO's are now routinely replacing known outdated supplies.This is free of charge if the electrical contractor contacts them and explains the situation.

I have just carried out a job where the occupant has been in the property for 57 years without any works being carried out on the electrics.

However a new shower has been fitted, a new meter and some conservatory lights. The occupant is 83, and the grandmother of my employer, which is why I am doing the work. The consumer unit is a master. Its a steel skeletal unit the steel wire earthing is still in place, however the cloth and paper singles have been replaced with VRI cable.

So a new meter and a new electric shower and still no distribution upgrade, no RCD protection.

We have installed a wet room, as she is now confined to the ground floor. She will be supervised during shower and toilet visits, and all this has been done to assist in a little quality and dignity in her final years.

I have only altered the lighting circuit, so have installed a RCD fused spur for the lighting feed, and upgraded the main bonding and equipotential bonding.

I have disconnected the sockets in the conservatory, and if she wants power outside now she would need a 20m extension cable.

What really aggravates myself is that electricians have been involved in the new shower install, and the conservatory and still left the old consumer in place!!

For the record the new shower was installed 4 years ago.

 

[steptoe]

I done a house last week,

overhead supply, all labelled up as PME,

was it F.?!

I disconnected the earth and stuck a couple of test rods in,

the readings I was getting suggested going to star point and back again  :shakehead