Earthing a TNS

[ElectricDunc]

Starting a partial rewire and consumer unit upgrade in a couple of weeks time. At the moment the service head has 2 lead cables coming in to the bottom of it which some bright spark has wrapped a couple of EC15's round which is a bit of a no no. Does anyone know where to get the proper copper earth tags that the electricity board use or is it a case of forking out for them to come put a proper MET in or a PME?

Thanks in advance.

Dunc

 

[JonoPashley]

Call the DNO not our problem to sort their equipment even tho it was probably some numpty spark who thought EC15s would be a great idea.

 

[rebuke]

Presumably it could also be a TT, and the DNO aren't supposed to provide an earth at all, at which point you'd have to put in a spike...

 

[ElectricDunc]

Definitely not a TT supply. Worked on a few properties in that area of town and it's all TNS systems and considering the Ze obtained from the lead sheath its a dam good earth as well.

 

[securespark]

If it's a good Ze, why fret? If it's poor ring up the DNO tell them there's a poor earth on their TN-S cable and get them to worry about it. Don't try & fix it yourself, those cables need to be handled with care.

 

[ElectricDunc]

My concern is the EC15's, i don't want to put my name to an installation where that sort of arrangement is present. I'll give my DNO a call and get them to sort me out with an MET.

 

[securespark]

If you're not happy, leave paperwork with the customer highlighting your concerns & ask the DNO to look at it with a view to rectifying it.

Trouble is, IME, many DNO engineers have declined to accept responsibilty where the cable has been messed about with by people other than them, so they may insist on a charge being levied. You have done all you can by highlighting the situation to both the customer and the DNO.

Leave the ball in their court. The most important thing is that the Ze is stable & low enough.

 

[ban-all-sheds]

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131.8
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[securespark]

If the Ze is stable & under 0.8 (and done PEB's), then you have satisfied that reg.

 

[ban-all-sheds]

No you haven't, not if as a qualified professional you know that the connection to the supplier's cable is an unauthorised, and possibly dangerous, alteration.

 

[plugwash]

Mind you I have heard of some cases of the suppliers saying that such setups are acceptable and refusing to do anything about them.

 

[securespark]

Mind you I have heard of some cases of the suppliers saying that such setups are acceptable and refusing to do anything about them.

So have I! UU often look at these and say they're not official, but if the ZE is stable and within spec, they refuse to alter it.

 

[ebee]

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131.8
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Well said that man.

You`ll be agreeing with Mark Coles next.
LOL. Only Joking. He did say this though which is in complete agreement with what you said and (unfortunately) not what the NICEIC said.
They said just to put a note on the EIC if distributors earthing arrangement is not adequate. I felt very let down by their advice on this occaision.

In essence, if their bit aint reet and you rely on it (TNS or TNC-S) then your bit is not reet innit? Ignoring it is not an option. Carrying on regardless is not an option. Do the right thing or walk away without touching it.

As Ban said 131.8

 

[securespark]

I have to disagree.

If, like I have experienced in the past, the DNO inspects the EC14, shrugs his shoulders & says it's OK, what do you do?

The Regs don't cover the DNO's equipment and the DNO engineer tells you that as far as he is concerned, it is acceptable...

 

[ban-all-sheds]

Ask him to put it in writing.

Tell him that you'd like an official confirmation from the DNO, on headed paper, signed by a suitable manager, that the use of the clamp is acceptable and safe.

Once you have that you really can say that you have exercised reasonable skill and care, and that to the best of your knowledge and belief.....