2.5mm earthing conductor from TN-S supply

[Chr!s]

Those belong to the distributor.

Agreed, though they still they still need replacing or enclosing.

 

[GaryM]

Agreed, though they still they still need replacing or enclosing.

Won't they be PVC/PVC insulated conductors?

 

[Tuttle]

Won't they be PVC/PVC insulated conductors?

Yes, I'm pretty sure that they are, but I have to say that I didn't look that closely (I'm only adding an outside light to an existing circuit).

 

[Rumacoai]

I have heard of earth conductors being left off all together, because when its added it starts tripping circuits, and if you add 16mm then it becomes your responsibility to fix. It may be it was the only size that didn't trip the circuits. Could open a can of worms. Just a thought, a bit of a dilemma.

 

[malcolmsanford]

Sorry Rum can you explain that one

 

[GaryM]

An earthing conductor responsible for tripping circuits? More likely a faulty circuit or appliance tripping an RCD.

 

[Rumacoai]

Its not happened to me, but another spark mentioned it in a conversation, I thought it strange but as it may have been relevant I thought I would mention it. I did not ask what and how faults occurred but will get back to them and ask see if I can get a better explanation as how things were fixed. Sorry if I have confused anyone, not my intention, fore warned is fore armed I thought. Off to football now, 48 I should know better really, should stick to dominoes. cheers

 

[Tuttle]

I can see how disconnecting a faulty circuit from earth would stop it tripping an RCD as there would be nowhere for the fault current to go. This is obviously extremely dangerous though as there would be no fault protection and as the circuit is already faulty exposed parts would probably be live!!!

I think that swapping a short length of 2.5mm for a short length of 16mm though can have no effect. The difference in the resistance of a 200mm length of 2.5 and a 200mm length of 16 is of the order of 0.001 ohms, which is very insignificant compared to Ze. I think that the only difference is that if you short meter tails to earth the suppliers fuse will go bang before the earthing conductor melts.

 

[GaryM]

Lol, you're never too old and never admit it if you feel that way!
I'd say break a leg but probably not a wise thing to do

 

[Tuttle]

Thanks Rumacoal, be interested to hear if you do find out more about that

 

[peanutty]

hi guy's, i was told once by an edf dno engineer that no one but dno should really touch the main earth connection at suppliers side, PME or TNS, personally i'd put in a 16mm earth and leave cert. or you could call supplier of lecky/dno and report sub standard main earth.

 

[peanutty]

DNO may even install PME at no cost when there if calcs are ok.

 

[telectrix]

10mm is the recommended size for TN-S, and is more than adequate by calculation so why bother with 16mm?

 

[peanutty]

10mm is the recommended size for TN-S, and is more than adequate by calculation so why bother with 16mm?

to make the drum lighter!!!

 

[telectrix]

i've got a rizla lighter, but never seen a drum lighter, or an old holborn lighter, come to that.