Please tell me what earth system this is!!

[DurhamSparky]

Right lads here is one for the books!!

Tns or Tncs.

 

[Strima]

TN-SCS... :lol:

 

[Knobhead]

Be interesting to know if there’s any current flowing?

 

[mechelec]

TN-C-S seen loads done like this. Why is it one for the books?????

 

[Richard Burns]

TNCS with bonding to the supply cable sheath

 

[StuSpiers]

Yhea that happens more than you would think makes filling out the test form tricky.

In fact I have exactly that situation in my own house!

 

[DurhamSparky]

The property was originally TNS at some point

When it got renovated I highlighted the lack of proper earth as the clamps had come away from the cable sheaths at the head.

Nedl said and it would be better if upgraded to PME as the network had been recently upgraded in that area

I agreed as landlord was paying for it!!

Just surprised me as to why they bonded to the sheath!! I'm not fussed as it goes down on paper as PME

Never seen it done , normally one or other!

 

[sedgy34]

its a tncs bcdefghijk lol

 

[Engineer54]

Disconnect the sheath bonding cables!!!! From your explanation, this DNO cable is also supplying TN-S earthing to other customers.

Whoever from the DNO that connected the sheaths to a PME connection needs bloody shooting... The two systems need to be kept separate when the cable is in progress of being PME'd....

 

[Knobhead]

One of the reasons I asked if there was any current flowing.

 

[Guitarist]

I think a query with the DNO is in order. Let them either sort it out or tell you that they think it's great

 

[sheppertonspark]

If you call it by the old description PME (protective multiple earthing) it makes more sense. For safety, in case the neutral becomes open circuit in the distributors network the neutral is "earthed" at "multiple" points along its run. I can see no issue with this arrangement that you show although it is a little unusual. I would call it T-N-C-S.

 

[telectrix]

all it needs is a rod bunging in. (18th?).

 

[MrLights]

This type of earthing is called TN-C-S or PME, and should be recorded as such. As you should be aware, the neutral conductor is tied down to earth at every joint made underground by your DNO. Although not widely adopted until the 70's the introduction of PME was piloted in the 1930's. It saved the REC's (at the time) hundreds of thousands of pounds overnight by changing from split concentric, and others, to concentric.
I could be wrong. Am I missing something? I'm open to discussion!

 

[7029 dave]

Double

 

[MrLights]

Double

Hey Dave! Birds of a feather...

 

[dmxtothemax]

armoured and or sheilded cables all grounded as they should be !
no great revelation there !

 

[DPG]

Blimey this thread was over 5 years old !!

 

[Leyland30]

How / Why has it been unearthed - no pun intended