TT earth systems versus TN earth systems

[danmoriarty]

Here is my brain fart on how I understand the common earthing systems use in the uk

domestic situations)(this is a rather crude assessment and more detail can be added by other members. I welcome both criticism and praise)

BS 7671 lists five types of earthing system:

TN-S, TN-C-S, TT, TN-C, and IT.

T = Earth (from the French word Terre)

N = Neutral

S = Separate

C = Combined

I = Isolated

First and foremost I have included a link to calm everyone down a bit in this thread so we can get back to having some good debate. http://i1169.photobucket.com/albums/r517/danmoriarty/hero.jpg

so....

What is an earthing system?

An earthing system is installed as an integral part of an electricity distribution system.

The earthing system has the following purposes:

 

[springcrocus]

Nicely thought-out and constructed post, Dan. I don't agree 100% with everything you have written but that is subjective. :Applaud :Applaud

 

[OnOff]

Ref post #63.........

Obviously spent quite a bit of time putting that post together but a glaring error IMO there being out forward as FACT. Quote: "This earthing system is also known as PME"......erm, NO not strictly speaking. TN-C-S can be PME but equally the supply can lack the intermediate pole earths hence a rod may be required. I'm simplifying it but IMO the distinctions should have been made. Why not also put some PROS up for the TT system. Current climate of metal theft and your Ze on a TN-C-S could unknowingly rocket over night!

 

[danmoriarty]

Ref post #63.........Obviously spent quite a bit of time putting that post together but a glaring error IMO there being out forward as FACT. Quote: "This earthing system is also known as PME"......erm, NO not strictly speaking. TN-C-S can be PME but equally the supply can lack the intermediate pole earths hence a rod may be required. I'm simplifying it but IMO the distinctions should have been made. Why not also put some PROS up for the TT system. Current climate of metal theft and your Ze on a TN-C-S could unknowingly rocket over night!

I am aware that i didnt make the distinction between tn-c-s and pme, and i may at some point make additions to the post based on other members recommendations (i believe i did include some pros and cons of tt but they were typed out in a different format). Truth be told after i typed it out earlier, the beach and surf board were calling so just saved it with the intention to add more (could have gone on to talk about IT systems or made references to BGB) but its late and CBA so id hoped others would find flaws and make suggestions with what to improve on.

In an effort to encourage discussion, maybe we could all collaborate and create a small document that relates to the benefits of each system?

 

[springcrocus]

Current climate of metal theft and your Ze on a TN-C-S could unknowingly rocket over night!

No self-respecting pikey would nick the neutral and leave the live/line/phase conductor behind. And they'd probably nick the pole for firewood. Bit difficult, anyway, with concentric!

 

[kme]

Snakehips:

As John says - I believe that, in the majority, your almost limitless knowledge is extremely appreciated - certainly by me, anyway

Plus having worked with you more than once, I`d back your corner in any discussion - because you either know, or find out. Shame that isn`t a more widely practised practise

Unphased: It isn`t you; Adminio has stopped ALL post editing - didn`t you read the memo? It made threads extremely difficult to follow, when someone removed a bit that was referred to later.

KME

 

[apprentice87]

Hi all,

"As John says - I believe that, in the majority, your almost limitless knowledge is extremely appreciated - certainly by me, anyway

Plus having worked with you more than once, I`d back your corner in any discussion - because you either know, or find out. Shame that isn`t a more widely practised practise"

Best quote i have ever read.

Without Paul, this forum would be a much poorer place....

john..

 

[Steve3948]

I wonder what the TT & TN % is across the UK 10% 90% ??

 

[sb_89]

Every one in ten a TT ? I'd hazard a guess at less, it's all regional dependant though, interesting to find out

 

[unphased]

Fantastic post by Danmoriarty. Well done.

TN-C-S and PME. is it not that TN-C-S has definition and PME is a colloquial term?

 

[Voltimax]

UP I have a question for you.

Have you ever had anyone punch you in the gob?

If you haven't, then I'm bloody amazed. You truly are insufferable.

 

[steptoe]

Fantastic post by Danmoriarty. Well done.TN-C-S and PME. is it not that TN-C-S has definition and PME is a colloquial term?

Here is my brain fart on how I understand the common earthing systems use in the ukdomestic situations)(this is a rather crude assessment and more detail can be added by other members. I welcome both criticism and praise)

BS 7671 lists five types of earthing system:

TN-S, TN-C-S, TT, TN-C, and IT.

T = Earth (from the French word Terre)

N = Neutral

S = Separate

C = Combined

I = Isolated

First and foremost I have included a link to calm everyone down a bit in this thread so we can get back to having some good debate. http://i1169.photobucket.com/albums/r517/danmoriarty/hero.jpg

so....

What is an earthing system?

An earthing system is installed as an integral part of an electricity distribution system.

The earthing system has the following purposes:

 

[danmoriarty]

he could just have looked here :innocent

oooooooo yours is all sticky as well I find it doesn't hurt to write out what you know occasionally, and i was hoping it might generate some actual debate on this thread rather than trying to take chunks out of each other. I might come across a real debate one day :shakehead

 

[steptoe]

difference being Dan, you have put opinions in your post disguised as fact,

BTW, IIRC it was only made a sticky so students etc could have an easy to find point of reference instead of all the usual debate about TNCS and PME being the same thing.

 

[danmoriarty]

true, i know it wasnt perfect :coat

Wasn't trying to compete, just using forum for its purpose i guess.

I enjoyed your post :Salute

 

[Voltimax]

Chunks are only taken out of people who deserve it and practically ask for it as Unphased does. He has a history of stirring it up and basically insulting those who've been doing the job a lot longer than he has. He used to wind everyone up at the screwfix forum until they sent him crying to the Napit forum, now it seems he's here and already he's upsetting folk and trying to tell the moderators how to do their job.

Well I'm sorry, but I for one am bloody sick of it.

 

[Manator]

I really love it when people post their views, and yes we do have some variants of earthing systems in this country, but what the majority of you are forgetting is that all of them are connected to a ROD.

 

[Voltimax]

I really love it when people post their views, and yes we do have some variants of earthing systems in this country, but what the majority of you are forgetting is that all of them are connected to a ROD.

Yes and doesn't it make you worry?

Customers just assume their "Electrician" knows his eggs. Good job they don't come here and know which of the dumbass posts belong to their "Electricians".

 

[unphased]

UP I have a question for you.Have you ever had anyone punch you in the gob?

If you haven't, then I'm bloody amazed. You truly are insufferable.

I can see your point of view. I have made some serious errors of judgement. Probably gone too far haven't I. No I haven't gone crying on to NAPIT forum and I still use screwfix. Insufferable? Blimey I hope not. Are things really as bad as that? :Blushing