Routing of meter tails

[leep82]

hi all any advice on the following scenario much appreciated. I have taken on a rewire from another electrician whos personal circumstances mean he cant finish the project. Majority of the first fix has been completed including the repositioning of the DB. The original DB was situated inside the kitchen base units adjacent to the meter and cut out. I can see why the DB is being moved as it isnt the most accesible of places and a new utility room is being created which is much more suitable. However it is the routing of the new ‘ tails’ that im not 100% comfortable with.

25mm double insulated tails along with a 16mm CPC have been run at low level behind the new kitchen base units before rising up in a PVC trunking to ceiling height. They then run approximately 8mtrs through the joist before again dropping down in a PVC trunking to what will be the new DB position. At no point are they buried in a wall. Personally i would have used 16mm2
T&E but the ceiling is now boarded and skimmed so the customer and builder is very reluctant to drop the ceiling and allow me to do this. The intention is to provide our own overcorrect protection at the origin so as not to be solely relying on the 100a DNO fuse.

Ive searched varies threads looking for an answer or advice so apologies if this has been done to death. Can anyone point me in the right direction of where to look in the regs or offer any other advice

 

[leep82]

If it is a TN system an rcd is

Going away from who has the biggest core...

Is the OP concerned about the vulnerability of the animal wagging parts,where they have been installed?

I get the feeling,this may be his concern.

sorry for the late reply, yes this is a concern. It is a TN system NOT TT so as pointed out earlier in the thread RCD protection not required.

 

[DPG]

Animal wagging? I've checked the regs and I can't find this.

 

[leep82]

I can't see what fitting 16mm twin and earth would help? Especially as the cpc size would be too small

A seperate cpc would have been run along with the T&E

 

[Midwest]

sorry for the late reply, yes this is a concern. It is a TN system NOT TT so as pointed out earlier in the thread RCD protection not required.

Thought you said the tails were installed under floorboards, are they more than 50mm...?

 

[leep82]

Thought you said the tails were installed under floorboards, are they more than 50mm...?

Yes they are although i didnt install them myself

 

[Midwest]

Which goes back to the dilemma of you first energising part of an installation, someone else has installed. Not trying to be clever, just wonder how you would cover yourself on the EIC, not having inspected after installation.

Must be a solution, as this happens more than not?

 

[leep82]

Which goes back to the dilemma of you first energising part of an installation, someone else has installed. Not trying to be clever, just wonder how you would cover yourself on the EIC, not having inspected after installation.

Must be a solution, as this happens more than not?

Fully agree and as mentioned if it wasnt an install previously started by another electrician i trust i would not have taken the job. I guess im more concerned about the use of the double insulated meter tails. Althought they are ran together and at a suitable depth ( 50mm from floor and ceiling ) i still worry that either conductor could become damaged and the fault not clear, the use of a T&E or SWA would surley reduce this with all conductors being enclosed together.

 

[DPG]

I still don't see how T&E would be an improvement??

 

[leep82]

Which goes back to the dilemma of you first energising part of an installation, someone else has installed. Not trying to be clever, just wonder how you would cover yourself on the EIC, not having inspected after installation.

Must be a solution, as this happens more than not?

Fully agree and as mentioned if it wasnt an install previously started by another electrician i trust i would not have taken the job. I guess im more concerned because of the cable

I still don't see how T&E would be an improvement??

wouldnt you have more chance of hitting multiple conductors in a T&E, say with a nail or screw and in turn creating a short circuit causing my OCPD to operate. The way that the cables are installed shouldnt give rise to this happening, but whats stopping Mr Builder sending a 3” screw into a floorboard?

 

[DPG]

You cant rely on t&e to perform like that.

And as long as the cables are correctly installed then screws aren't a problem. You might as well say what if he uses 6 inch nails.

 

[Pete999]

You cant rely on t&e to perform like that.

And as long as the cables are correctly installed then screws aren't a problem. You might as well say what if he uses 6 inch nails.

The World is full of "what ifs"

 

[leep82]

You cant rely on t&e to perform like that.

And as long as the cables are correctly installed then screws aren't a problem. You might as well say what if he uses 6 inch nails.

I get that, but i wouldnt also rely on the current set up to perform like that either, although more chance with a T&E. Can i ask why a SWA seems to be a preferred method?

 

[Pete999]

I get that, but i wouldnt also rely on the current set up to perform like that either, although more chance with a T&E. Can i ask why a SWA seems to be a preferred method?

Earthed Amour maybe?

 

[leep82]

Earthed Amour maybe?

Without wanting to sound stupid what is tht earthed armour offering ?

 

[Pete999]

Without wanting to sound stupid what is tht earthed armour offering ?

RCD not needed

 

[leep82]

RCD not needed

Because?

 

[PEG]

Without wanting to sound stupid what is tht earthed armour offering ?

A much,much better chance,of conductors being "hit",in the correct order

 

[PEG]

Without wanting to sound stupid what is tht earthed armour offering ?

A much,much better chance,of conductors being "hit",in the correct order

 

[PEG]

Animal wagging? I've checked the regs and I can't find this.

...Someone pulled a face at using the common parlance,so i substituted "animal wagging stick",for "tails" i ran a test on my 9 year old...and he got it!

 

[leep82]

RCD not needed

Because?

A much,much better chance,of conductors being "hit",in the correct order

i absolutely agree. So would a T&E not offer a better chance than the installed ‘ tails ‘. Just trying to justify why T&E might have been better than the tails.

 

[DPG]

Not sure why you keep wanting to justify that opinion. It has no relevance as far as regs are concerned.

 

[leep82]

I just feel it would have been a better installation method than using 25mm2 tails. Earlier in the thread it was asked what would be gained from using T&E over the tails, so im just trying to provide some reason for it. Whilst there may not be any relevance to it s far as the regs are concerned, can we not apply the same reasoning.

 

[Midwest]

I came across a fault a while back. The previous owner had installed some dado rail on the landing. He secured the rail using some harden nails, one clipped one of the strappers for the two way landing light, in a piece of tw&e. Didn't touch cable cpc. He did a perfect job, touching the copper of the conductor, but not severing it, so light & dado rail worked perfectly. Until that is the next owner had the bathroom refurb'd, and the plumber and all, were getting shocks off the bathroom wall, when touching the plumbing.

So could of been tw&e or sheathed/insulated, result would of been the same

 

[leep82]

Yeah im not saying its by any means fool proof, i just feel theres more chance of striking more than just the one conductor when using a T&E

 

[Octopus]

RCD not needed

And if installed correctly, the anything penetrating the sea is almost certainly going to take out the fuse ....

 

[Ian1981]

And if installed correctly, the anything penetrating the sea is almost certainly going to take out the fuse ....

The sea??

 

[Octopus]

The sea??

poxy predictive text

SWA

 

[Pete999]

Because?

If the cable is less than 5mm below surface it has an earthed sheath as in conduit MICC ETC

poxy predictive text

SWA

I knew that Honest

 

[leep82]

I agree with everything thats being said, but im obviously alone in thinking the T&E method has its benefits over the sheathed/insulated tails.

 

[Pete999]

I agree with everything thats being said, but im obviously alone in thinking the T&E method has its benefits over the sheathed/insulated tails.

So what do you think that tells you Leep82