Main Earth Conductor

[Wattsy]

Hi,

I'm using my comsumer unit change for my initial NICEIC assesement.

Its TN-S supply with a 6mm earth conductor which i know should be 16mm if selected from the table and if the Adiabatic equation is used it work out to just below 10mm.

I have phoned the DNO and asked for it to be upgraded but after searching the forums there seems to be a lot of people saying to take the 6mm to the MET then just take the 16mm from there to the CU.

60A fuse

16mm tails

PFC 4.5ka

Ze 0.07

When talking to western power i get the impression that not many people ask for the earth conductor to be upgraded so i'm wondering what other people do and what the NICEICS view is?

Many Thanks

 

[Theorysparky]

What is the condition of the clamp ???

if you can remove and replace the cable then i would do that

but it depends on the condition of the clamp

failing that i would take 16mm from the met to the cu

 

[Wattsy]

Its all wrapped up. Didn't really want to mess aroung with it. So you'd leave the 6mm to the MET?

How will that go down in my assessment?

Its only a short piece of 6mm and the Ze's good:C

 

[Lee321]

the dno side is their side and your only concerned with from met

 

[Wattsy]

Do you mean from the MET to the CU.

What About 131.8?

Back to work back later

 

[Lee321]

exactly

 

[Theorysparky]

16mm from MET to the cu

Put this down as a deviation

Dont worry if you are picked up on it ,,your assessor will advise you

you wont fail because of it

 

[m4tty]

That's dnos property and your not allowed to change it. That's what I was led to believe anyways.

 

[Theorysparky]

I remember something like this years ago

i called the DNO out,,,he was there the same day

looked at it and said it was ok told him the readings he was happy off he went

 

[sparkytim]

As others have said YOU are not responsible for DNOs connection and must not touch it.

Just connect it into an Earth block if not already and this becomes YOUR MET

FROM there to Your Consumer Unit is YOUR earthing conductor that goes down on EIC.

 

[batty]

With a good earth reading like that you have no worries as said take it into a 4 way earth block after sleeving with green a yellow sleeving and take a bit of 16mm from there to new consumer unit. You have then done your bit. The only time I change them is when they have tenby clamps and I then replace them with proper clamps.

 

[Wattsy]

Thanks for all your help guys

 

[AAAMUSEMENTS]

Some service heads have a very accessible MET with allen screws, so you could in theory just connect in a new piece of 16mm.

Some others have a sealed earth cover, but helpfully provide an outline of where to drill through the plastic to get to the allen head below. Of course you shouldn't do this, but if the fuse-fairy were to do it for you while you weren't looking...

 

[steptoe]

Some service heads have a very accessible MET with allen screws, so you could in theory just connect in a new piece of 16mm.Some others have a sealed earth cover, but helpfully provide an outline of where to drill through the plastic to get to the allen head below. Of course you shouldn't do this, but if the fuse-fairy were to do it for you while you weren't looking...

its TNS

and IIRC 6mm is adequate.

code 4 if you must,

but its perfectly acceptable,

in fact NICEIC inspector asked me about this last week on inspection.

he said 6mm on TNS was fine unless exceptional circumstances.

as does the big red comic

 

[initforthemoney]

The only time I change them is when they have tenby clamps and I then replace them with proper clamps.

Which you are not supposed to do.

 

[tom1]

Some service heads have a very accessible MET with allen screws, so you could in theory just connect in a new piece of 16mm.Some others have a sealed earth cover, but helpfully provide an outline of where to drill through the plastic to get to the allen head below. Of course you shouldn't do this, but if the fuse-fairy were to do it for you while you weren't looking...

ever put your main bonding in there?

 

[a1spark]

Tom ,I have seen Main Bonding cables terminated at this point at the service head, and strangely enough sealed up too. This is not the correct position cos the supply authority equipment should not be tampered with in any type of way O)

A seperate MET block should be used or alternatively the consumer unit Earth Bar if possible and / or preferred

 

[ianmacd]

its TNSand IIRC 6mm is adequate.

code 4 if you must,

but its perfectly acceptable,

in fact NICEIC inspector asked me about this last week on inspection.

he said 6mm on TNS was fine unless exceptional circumstances.

as does the big red comic

Where abouts in the RBR does it say that steps?

 

[steptoe]

Where abouts in the RBR does it say that steps?

by calculation,

obviously if you are installing to 17th you put 16mm in but not required as a retro job.

 

[ianmacd]

by calculation,obviously if you are installing to 17th you put 16mm in but not required as a retro job.

Sorry, I thought you were implying 6mm was fine on tns without calculation despite the case in this thread in which it had been calculated at 10mm.