Earthing Arrangement (TN-S or TN-C-S or a Frankenstein Creation?)

[Clarkie]

Evening Chaps

As can be seen in the attached photo , the incoming supply cable has a Earth soldered to the outer sheath of the cable suggesting an TN-S Earthing Arrangement, however a Main Earthing Conductor can be seen coming from the supply head to the MET suggesting a TN-C-S Earthing Arrangement. So thoughts and suggestions on what I would show this as on an EICR? MTIA Clarkie

 

[DefyG]

Test it, it will prove to be one or the other.

 

[Clarkie]

Ze came back as 0.11 ohms so within tolerance for either!

 

[GBDamo]

Ze came back as 0.11 ohms so within tolerance for either!

Even if its TN-S at the intake its probably TN-C-S 100 yards down the road.

Speaking with DNO engineers, repairs and replacements are TN-C-S. This is all urban, not sure the same applies in rural networks.

Vaguely remember on my, only used once, EV charger course they recommend treating everything as TN-C-S for the above reason.

A quick resistance measurement N-E will only confirm its definitely TN-S. Depends if the earth is passing through the cut-out or is linked to Neutral inside.

 

[bill01803]

I would say it is best to take every supply as TNCS as you don’t know what they have done repairing and altering the supply cable down the line. I have seen aluminium concentric joined to old lead paper making the supply TNCS

 

[DefyG]

Ze came back as 0.11 ohms so within tolerance for either!

Was hoping you might come back with 2 Ze results one to the sheath (TN-S) and one to N (TN-C-S) for PME. but if both the same it must be PME but as per post#4 speak to DNo to be sure.

 

[cliffed]

Get rid of that debris first ….if you dare

 

[Clarkie]

Get rid of that debris first ….if you dare

I know, all cleaned now but you should have seen inside the DB it looked like a builders bucket!! Thanks for all the reply’s Chaps

 

[Mike Johnson]

A good builder keeps their bucket clean otherwise it mix's with the mortar and compromise's any brick laying spread.

 

[nicebutdim]

I think it was a figure of speech, Mike.

 

[Mike Johnson]

A bit like saying plumbers makes good electricians.