TN-S Earth

[donkey08]

Hi, can anyone help ar advise on the following. I've just gone to check a dist board for carrying out a replacement, it is a TN-S system. The main earthing conductor is bonded to the supply cable sheath via a standard earth ( pipe ) clamp, of the tenby type. It looks as if the installation was rewired 15-20 yrs ago - all cables have incorporated cpc's ete. Was this method of obtaining a bond acceptable then, and is it still, or should i convert to a TT system? I know i should check the integrity of the incoming earth first, if it is ok, should i carry on as usual with a split load high integrity db.
Thanks, Donkey08

 

[Deleted member 9648]

No it has never been an acceptable method as tenby clamps are not a reliable way of clamping to a lead sheathed cable and may even cause a short (explosion!!!) if they are overtightened and crush the soft lead sheath.Best contact the supplier to see if they will provide an earth or as you say TT it.

 

[donkey08]

Hi, yes i thought that was the thing to do, i will contact the network supplier to see what they say, i will let you know the outcome. Many thanks.