A little help with the Reg's.

[Top Cat]

Just quoting for a C/U change, scenario is:-

O/S meter box, PME, existing 60A switch fuse in meter box, 16mm TWE from switch fuse to C/U in center of house with 16mm TWE coming down wall to C/U embedded in plaster, no bonding to water or gas.

Because the C/U is situated in center of house and all recently decorated it is virtually impossible to get anything new to it.


What i want to do is fit a 100A, 30mA, time delay RCD with 63A MCB in outside meter box.

Run 10mm G/Y to water and gas from meter box.

Change C/U.

I would love to upgrade the earth from meter box to new C/U but i don't think it is an option (obviously only 6.0mm earth in 16mm TWE).

Is this a "hanging offence" or do you think it is OK?

 

[telectrix]

i would state on cert. as CU change only and try to upgrade the main earth. the T/E buried in the wall was done to previous regs and you're not obliged to RCD protect it.

 

[Top Cat]

i would state on cert. as CU change only and try to upgrade the main earth. the T/E buried in the wall was done to previous regs and you're not obliged to RCD protect it.

When you say"i would state on cert." not sure what you are telling me what to state?

 

[Octopus]

he's saying that as the tails were installed previously you are not responsible for adding RCD protection.

God help us all if the clowns add this little gem to the next version of the regs.

 

[johnboy6083]

As the bonding will be upgraded by yourself, from the meter box, then IMO, the adiabatic is suitable for calculating the CPC to the CU, and 6mm should be fine.

 

[Top Cat]

he's saying that as the tails were installed previously you are not responsible for adding RCD protection.

God help us all if the clowns add this little gem to the next version of the regs.

I realise that but it is not clear from the post what he wants me to "state on the cert.".

 

[Guest55]

state nothing out of the ordinary on the cert and write nothing in the deviations section.
there are no rules against using the t&e cpc for a submains so crack on.
and if you did adiabatic im sure it will say less than 4mm for the earth. ;-)

 

[rattlehead85]

Had similar scenario last week which Biff kindly guided me on. The 6mm2 earth is fine if confirmed by the use of the adiabatic. However if you run new 10mm2 bonding to your internal consumer unit you must ensure the earthing is uprated to 10mm2 from the switch fuse. This would encompass a combined earthing and bonding conductor. Guidance notes 8 Earthing and Bonding will assist you with this.