NEW TAils or Not

[stidge]

Hi All, Know this has been mentioned 1000s of times but here goes.
Customer would like NEW CU. Currently 16mm T/E 8m Run from Meter to CU.No Gas Bond,6mm water
I would like to fit 60a fused isolator , 10mm earths to gas and water and re use T/E. Think the CPC on T/E
is 6 or 10mm. The Max demand is low. A Colleague has apparently done this '100s of times'. I think that to
comply I need to run a 16mm earth from meter to CU ?
Any advice please

 

[Andy78]

Where do the bonding conductors terminate ? MET near the meter with the earthing conductor or in the CU earth bar ?

 

[stidge]

MET near meter mate !

 

[Simonslimline]

Cpc is 6mm2

 

[Flanders]

If the gas and water nead bonding then i would run 10mm from met the adabtic equation should give you the answer

 

[Andy78]

MET near meter mate !

Then the CPC in the T&E need only comply with the requirements for a CPC for that distribution circuit and need not take into account size requirements for bonding.

 

[stidge]

Yes thanks Flanders , I was going to run 10mm for gas and water from met but do I NEED to pull in 16mm from met to cu ?

 

[stidge]

Thanks Andy so I can use T/E , run 10 mm to G and W and install 60a Iso ALL GOOD ?

 

[Andy78]

Thanks Andy so I can use T/E , run 10 mm to G and W and install 60a Iso ALL GOOD ?

Your calcs will tell you that.....I can't.

 

[Leesparkykent]

What's the earthing arrangement? Have you carried out the adiabatic equation?

 

[Flanders]

I would say ths 6mm is suitable to the supply ths db as you are not taking the bond from tbe db

 

[stidge]

TNCS arrangement

 

[Leesparkykent]

543.1.1

 

[stidge]

Thanks for all replies , time to get book out and do AE

 

[davesparks]

I would say ths 6mm is suitable to the supply ths db as you are not taking the bond from tbe db

Without any information as to the prospective fault current or Zs requirements of the final circuits fed from this submain?

 

[Flanders]

Sorry Yes i agree you realy do nead to do all the calcs but from past experance of your basic house a 6mm should be big enough