16mm meter tails, do they always need upgrading

[chopper]

just a quick question folks, when changing a mains do u have to upgrade the tails to 25mm and earth to 16mm, at the min there is 16mm tails live and nutral and neutral and the main earth is 10mm,<br>it is a tncs system and the ze is 0.16, gas and water are also bonded with 10mm,<br>do they need upgrading its only supplying a old wylex 4 way board at min<br>cheers in advance for an info

 

[tonyjones]

Sizes of earthing conductors are listed on page 28 table 4.1 on site guide.

 

[DaveyD]

No what we have to do is be guided by the regulations and as designers either adhere to the regulations or have a pretty good argument as to why we don'tThe OSG is a guide to the regs, in a lot of cases a good guide but they are not the regs. They often quote a relevant regulation but in the case of tails it only quotes regulation 514.3 when advising about the 25mm size and that regs is just for conductor identification and as always it is the distributor that as the final word

Agreed, thanks for the clarification. Ive had this discussion before where the OSG says "should" be 25mm2 (but as you say does not back up)

 

[chopper]

this is what i didnt know , and was just wondering

 

[chopper]

to let you all know, i changed tails anyway, thought they would be tight to get out as they was in cavity and db was on anothr wall, but taped on they all pulled through,mains change tails upgraded to 25mm earth upgrade to 16mm and gas and water upgraded to 10mm, all tested job done cheers though guys , was something i was curious about,

 

[trev]

Have you been breaking meter seals chopper?

 

[telectrix]

they were missing , obviously.

 

[chopper]

yeah they were missing