3rd Floor Flat Lost Main Earth

[bilbo_88]

Hi All

3rd floor flat has incoming supply via Conduit which was being used as the earth. Conduit at some stage has failed leaving the property with no suitable earth.
Would it be necessary to run a new sub mains and renew the supply also or is it within the regulations to run a separate earthing conductor (although it would take a different route via the outside of the building).
And additionally to this, as it could be the case with more than one flat would it be acceptable to install a Marshalling Earth Terminal to potentially connect to the other 3 flats on the floor should they have the same issue?

Supply to building in TNS

Any advice is appreciated

Thanks

 

[Lucien Nunes]

I don't see a objection to running a separate EC so long as it is installed correctly in its own right. So the MET in the property can be reliably earthed but what about the conduit? We know that there is at least one break in its continuity; so long as there's only one it can all still be earthed from the two ends. But perhaps it is high-resistance all over the place and parts of it cannot now be effectively earthed, or perhaps it has completely rusted through and the cables are exposed? I would want to get an idea of what state it is in before making a decision that it is safe to leave the submain cables within it in service.