Earth cable mystery

[robinbetts]

Hi,

I've just had an old garage roof taken off, and i've just been running some new armoured cable to replace the old standard twin and earth that used to feed that building (surprisingly wasn't in very good shape!).

The roofers cut off the old twin and earth when they removing the old roof, no problem. But I've also spotted an yellow/green earth cable that's been cut off as well that runs into next door's outbuilding. There's no sign of where it ran to my end, if anywhere.

After looking in next door, it runs into a mini consumer unit. A small loop of earth cable then runs out of the unit and clamps round the exposed armour of the main feed into that unit.

My question is, should the earth cable that has been cut of be providing an earth for that consumer unit, and therefore all the circuits that run from it? Or may it have been there to earth something which might not even exist any more?

If it should be earthing the CU, can I just connect it to a new earthing rod?

Many thanks!

 

[securespark]

Next door's CU feed runs through your garage??

 

[robinbetts]

It's just their outbuilding, and it's just this earthing cable that runs along the top of our boundary wall, and it was tacked onto the side of the wall plate of my old garage roof. My garage backs onto their main building, so it's possible that the earth cable used to go in there somewhere. But theirs no sign of it that I can see!

 

[333rocky333]

Id suggest your neighbour gets there earth tested to there garage cu, its possible whoever installed there swa did not terminate the armoured at the house end, either through incompetance or purposely chose not to and TT'd the garage, the cable may have gone to an earth rod.
Can they check there end in the house to see how the swa connects
If they turn out to need a earth rod it needs installing correctly and on there property really.

 

[ericmark]

I have seen, specially around radio hams, where out building had a TT supply and that also included their neighbour. It was more to do with RF interference than safety from electric shock, but first thing would be ask your neighbour.

 

[ban-all-sheds]

 

[ban-all-sheds]

If it should be earthing the CU, can I just connect it to a new earthing rod?

It's not your CU - do not have anything to do with it, particularly providing an earth.

Tell them that their earth was running through your roof and therefore, unfortunately, it has been severed.

Advise them to get an electrician to sort it out, and in the meantime isolate the supply to their outbuilding.

 

[John D v2.0]

Presumably that earth cable is to parallel the swa shield to allow enough CSA? But the electrician didn't know what he/she was doing as they have used an earth clamp for a copper pipe which is not suitable for SWA. So they need an electrician anyway to sort that out, and while they're there they can check the earthing arrangement.

 

[ban-all-sheds]

You forgot something:

But the "electrician" didn't know what he/she was doing...

 

[robinbetts]

Thanks guys,

I'm on good terms with my neighbour who is elderly, so don't really want to cut her cable then say "you sort it out" or "it's nothing to do with me" so I'll do what I can to help her get it sorted and put right if necessary.

I assume that the correct way to earth bond the swa is to use a gland kit and attach the earth to the tag?

Thanks again.

 

[EFLImpudence]

Perhaps ALL of next door's supply comes from yours.

Are your bills high?

 

[ban-all-sheds]

I'm on good terms with my neighbour who is elderly, so don't really want to cut her cable then say "you sort it out" or "it's nothing to do with me"

You don't have to - it's already been cut:

But I've also spotted an yellow/green earth cable that's been cut off as well that runs into next door's outbuilding.

I assume that the correct way to earth bond the swa is to ... attach the earth to the tag?

Or an earthing nut.