Meter Tails...!! 16mm / 25mm

[DurhamSparky]

Hi,

Going to be doing my Elecsa Assessment soon and house i have chosen to do the work on is a TNCS supply 6 way board with excellent access!!

currently it has 16mm tails from meter (located about 2M away on ouitside wall) earth is in 16mm and bonding is 10mm so not to bad!

however looking at previous posts and stuff in onsite guide it says the tails must be 25mm ( section 2.2.3)

now im confused??? is that for new builds or can i get away with utilising the existing 16mm cables??? or should i install new 25mm tails !!


much appreciated!!


steve

 

[sparks1234]

Is the board existing or have you installed?

How easy are they to change?

Whats the main fuse size?

 

[Guest123]

Hi.

What is the rating of the main service fuse???

 

[DurhamSparky]

the fuse board is in its original condition from 20 years previous, to change the tails would be a "pig" as they buried in the wall for the 2m length!!

never had a massive look at main fuse but was 100a i think..?

steve

whats the limit... is under 80a ok with 16mm and 80a and over 25mm???

sorry im ex military spark just converting to domestic so still all new!!

 

[Guest123]

If it is a 100A fuse then the tails need to be 25mm, also if they are buried in the wall, not enclosed in metallic conduit, they will need RCD protection.

Can you run surface trunking to the DB??

 

[DurhamSparky]

possibly be able to run surface trunking as its in a garage! may even be able to clip direct!! to save hassle!!

going to ring NEDL tomorrow and finds out size!! if it turns out to be 63 / 80a 16mm ok??

 

[sixfingers]

I take it NEDL are lecci board? If so they wont def know fuse size,best off checking yourself

 

[DurhamSparky]

well that was second option!!

snip peak! replace

 

[sixfingers]

Who said anything about The Snip?

 

[DurhamSparky]

oh yeah no snipping required the seal was already broken and fuse fell out into my hand!

 

[bramboy]

If it is a 100A fuse then the tails need to be 25mm, also if they are buried in the wall, not enclosed in metallic conduit, they will need RCD protection.

Can you run surface trunking to the DB??

RCD protection on meter tails?

 

[DurhamSparky]

do tails need rcd protection....!! yes / no ??? i have yet to come across one yet? my scope is small at the min like!

 

[Guest123]

Yes...The requirement to RCD protect cables buried in walls less than 50mm or not enclosed in earthed metallic conduit doesn't just mean twin and earth. Tails are PVC PVC are they not, and without mechanical protection will need RCD as per ol'red.

 

[DurhamSparky]

dont that then give you no discrimination??? 1 overall RCD in property!!

 

[Guest123]

Exactly.

That's why I suggested surface installing new tails, does away with the need for RCD protection.

IMO some of the changes between 16th and 17th editions are plain stupid, but who are we.

 

[DurhamSparky]

didnt want to really faf about with cabling!! im doing this job cost price!! argh!! oh well best order few meters of 25mm brown and blue tails!!! (go for 25mm then i don't care what size fuse it is..)

may investigate to see if current tails are in metalic conduit!!

 

[pennywise]

Hypothetically could you put earthed metallic capping over the area where the tails are running below the surface as long as the tails are going directly upward (chances are thats never going to be the case and you'd probably nail the cable in the process) , I would never do this as it's not best practice and would look ruff as anything, but does it matter that the capping isn't buried with the cables.

 

[DurhamSparky]

probably not!! cable comes in sideways and along wall then i guess goes up to the box..!!

oh well going to investigate bit more!!

cheers chaps...!!

 

[pennywise]

Sorry m8 didn't really mean in your situation It was just a discussion point as to whether it would comply. Good luck on your assessment when it comes.

 

[sparks1234]

oh yeah no snipping required the seal was already broken and fuse fell out into my hand!

yea...they all do that