naked ladies!!!!!

[VoltzElectrical]

no, actually, no real naked ladies, but

I done a EICR or PIR actually on an old house with apparent TT set up for earthing. 6mm earth cable coming up from the door step to the 3036 board. I disconnect the earth cable and do a Ze. Reading? - 0.11!!!!!!! Test between Live and neutral, same reading.

Can't see where connection made between neutral and earth. Any suggestions?

 

[jimmy_one_ball]

We has a similarly low reading from a TT recently and we definately had a rod, never did understand why as the neighbouring TT was 80 odd Ohms. As the earthing electrode is burried in concrete it may be a strip or lattice, or even the srtucture of the building? Dunno if these methods are known to give a low reading, be interesting to find out.

 

[Vonnegut]

Just to muddy the water.....

My house (1930's semi) has a PME head 100a (but no earth actually connected).

Old Wylex board with 1 x 6mm earth connected to the mains water supply (copper and lead), so actually TT (of sorts!)

Ze..... 0.58

I will get around to it one day......

 

[GLENNSPARK]

Just to muddy the water.....

My house (1930's semi) has a PME head 100a (but no earth actually connected).

Old Wylex board with 1 x 6mm earth connected to the mains water supply (copper and lead), so actually TT (of sorts!)

Ze..... 0.58

I will get around to it one day......

well...if your happy to just rely on extranious....
so what happens when the water lads start with their blue poly pipe?

 

[telectrix]

make 'em leave th old lead in the ground. it is then not extraneous, but a good solid earth rod

 

[GLENNSPARK]

make 'em leave th old lead in the ground. it is then not extraneous, but a good solid earth rod

had this carry on with an NVQ assessor a while back...
it was at a church where the new colours install was using the main water intake as its means of earthing (naughty)....so i tugged it...
anyway i made sure the water intake was still in service...if it had been redundant i would perhaps have given it a 3...
thing is i mentioned to this NVQ assessor about it and that if it could be proven that it would not be dismantled/removed in future then it was OK...such as a private borehole..
he told me it was nonsense...
yeah rite...

 

[hookedonfishing]

Oh you totally had me with the naked ladies. Bugger.

 

[Vonnegut]

well...if your happy to just rely on extranious....
so what happens when the water lads start with their blue poly pipe?

Of course I agree.

All my neighbours have converted to poly already (to improve water pressure).

So for the moment I have around 40 metres of lead all to myself.

Like I said..I will get around to it one day.....''the cobblers children go barefoot'' and all that......

 

[telectrix]

Of course I agree.

All my neighbours have converted to poly already (to improve water pressure).

So for the moment I have around 40 metres of lead all to myself.

Like I said..I will get around to it one day.....''the cobblers children go barefoot'' and all that......

what's your Ze of that lead earthing ?

 

[GLENNSPARK]

what's your Ze of that lead earthing ?

bet you its low...

 

[ackbarthestar]

I haven't read all of this thread but It appears to me that the TT property you are testing still has its MPB still attached. It wouldn;t surprise me that perhaps other properties have been PME'd in which case your main earth is via someone else's PME connection through the connected metallic services and your bonding.

I suppose if I had read the whole of this thread I might have discovered someone elses reply and then there would have been no point in this answer......lol

Did anybody else come up with the same answer ?

 

[VoltzElectrical]

I haven't read all of this thread but It appears to me that the TT property you are testing still has its MPB still attached. It wouldn;t surprise me that perhaps other properties have been PME'd in which case your main earth is via someone else's PME connection through the connected metallic services and your bonding.

I suppose if I had read the whole of this thread I might have discovered someone elses reply and then there would have been no point in this answer......lol

Did anybody else come up with the same answer ?

Yes, and they were all WRONG because they didn't read the post properly where I stated that the main earth was definitely disconnected so no parallel paths.

 

[boffy35]

I think the point that ackbarthestar was making is that even if your Ze test did only include the rod i.e. the cable was continuous along its length, that maybe a neighbouring property may have a TNS TNCS head with a good conductive path to the mass of earth. This means that your client's rod rather than using the path through the ground to the transformer tap point it is finding a parallel path external to the property.

 

[VoltzElectrical]

I think the point that ackbarthestar was making is that even if your Ze test did only include the rod i.e. the cable was continuous along its length, that maybe a neighbouring property may have a TNS TNCS head with a good conductive path to the mass of earth. This means that your client's rod rather than using the path through the ground to the transformer tap point it is finding a parallel path external to the property.

Ah, that is more clearly put and a definite contender for the answer.

Sadly we will never know as the customer had it PME'd and an isolator put in.