Hi, can someone tell me how to tell the difference in this in real life?
if the earth goes to the armoured sheathing then its TN-S but how do you identify a TN-C-S system?would there usually be a separate earth going down the main incomer with the live and neutrals?
I've heard that if the armoured cable gets corroded then you can convert to TN-C-S. I would expect this is done by the electric board but, how do you go about it in practise? Replace the whole cable or add in a very large earth to the substation?
Also, If the Earth and Neutrals are both grounded at the substation, arent they all really TN-C? - or this depend on where the Earth actually joins the ground in the substation?
And finally, doesnt a TN-S affect RCD's? or is this not a problem because of the neutral joining the earth before the RCD?
You answers are eagerly awaited!
if the earth goes to the armoured sheathing then its TN-S but how do you identify a TN-C-S system?would there usually be a separate earth going down the main incomer with the live and neutrals?
I've heard that if the armoured cable gets corroded then you can convert to TN-C-S. I would expect this is done by the electric board but, how do you go about it in practise? Replace the whole cable or add in a very large earth to the substation?
Also, If the Earth and Neutrals are both grounded at the substation, arent they all really TN-C? - or this depend on where the Earth actually joins the ground in the substation?
And finally, doesnt a TN-S affect RCD's? or is this not a problem because of the neutral joining the earth before the RCD?
You answers are eagerly awaited!