Another earthing question......

[polo1]

Hi folks,
story is, TNS supply to one side of a semi detached property. A three phase head, one for the property I'm working in, one for the adjacent semi and one unused.

The supply for the adjacent semi runs in VIR singles in conduit from the main head. Whils working away on my job, the neighbour pops in and asks me if I can have a look at his installation as he has been suffering from the single RCD covering the board tripping over the last month or so.

So, late yesterday afternoon had a look. First thing is Ze is 514 ohms. The board is tucked away under a stair and really difficult to access. I wasn't able to see how the main earthing has been achieved, but I'm guessing it's via an old lead water main.

Now, the question. Is it acceptable/permissable to run a 16mm earth from the suppliers head (where the property with the high Ze takes its supply from) next door? If not, it's going to have to be PME if available or TT. There is something that strikes me as not quite right taking the earth from the main head in the neighbouring property but that might just be me - it would certainly be the easiest option.

Still have not had time to investigate the cause of the tripping.

Opinions/advice welcome!

Regards.

 

[Engineer54]

And for those interested....got the bum's rush from the DNO (oldtimer - almost word for word to your post!) - "we'll programme it in, but if we've never provided an earth.........etc". VIR tails - "very common in domestic properties, we have no plans to upgrade at present, but if you have any concerns, let us know".

So from the head I just bonded to either end of the conduit, then to the CU and got a very respectable Ze. Then got an urgent call and I still haven't checked out the nuisance tripping.:35:

Think everyone knows that VIR tails are very common, ....60+ odd years ago!!! Is the service cut-out an old cast iron rewirable fuse unit?? If so.....

VIR tails and the cast iron rewirable service cut-outs are part of a Nationwide undertaking by ''ALL'' the DNO's to be replaced by i think 2011!! So how this joker can say his company have ''no plans to upgrade at present'' is a little bewildering? ...Perhaps a letter to the ombudsman may change there minds rather quickly!! lol!!

 

[oldtimer]

A bit like the UK standard voltage at 230v but as we all know nothing changed we still have 240-245v

I know what they are meant to do but in the meantime i think polo did the right thing to re-enstate the earth to and from the conduit because the tenant now has a good earth and no doubt he will get it sorted one day but not any day soon