TN-C-S vs TN-S

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electrics

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hi, What would you say when you compare these two system , which one is more efficient ? When do we need to choose TN-C-S ,I guess this is worse than TN-S since common neutral and earth conductor might effect bad result, but I wonder the use area of this system...
 
yes true,I dont know the equivalent of this system in usa. Anyway I think the answer is related to being economical:)
 
I'll clarify the need for clarification. I have two questions:
  1. What does "TN-C-S" mean?
  2. What does "TN-S" mean?
 
charlie b said:
I'll clarify the need for clarification. I have two questions:
  1. What does "TN-C-S" mean?
  2. What does "TN-S" mean?
Click to expand...


TN-S:

180px-TN-S-earthing.svg.png






TN-C:

180px-TN-C-earthing.svg.png




TN-C-S:

180px-TN-C-S-earthing.svg.png



It's grounding terminology from the other side of the pond.
 
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TN-S is a better (as in slightly safer in one particular respect) system than TN-C-S, but needs a lot more copper. So we use TN-C-S, which is good enough. TN-S is really impracticable as it makes distribution unwieldy and hard.

TN-C-S is the standard wiring method used within the USA, the UK, Europe, New Zealand, Australia, and most civilized countries of the world.

The -C bit means that the functions of neutral and Protective Earth (ground) are combined on one conductor, as is the case with the service supply. The -S bit means that from the service, the neutral and protective Earth (ground) condutors are seperate.

So you guys use TN-C-S every day. incdentally these terms are international, not European, they are IEC I think.

With TN-S the neutral and Protective Earth conductors are seperate from the point of generation or transformation.
 
electrics said:
hi, What would you say when you compare these two system , which one is more efficient ? When do we need to choose TN-C-S ,I guess this is worse than TN-S since common neutral and earth conductor might effect bad result, but I wonder the use area of this system...
Click to expand...

I know what a TN-C is. I know what a TN-S is. I don't know what a TN-C-S is.

ice

edit to add: Slow poster - already answered
 
kinda the part especially from xformer to service entry of a building is TN-C while the distribution inside the building is TN-S .....
 
From iwire's Rules for Posting thread at the top of every page:
* This NEC? Forum is for those in the electrical and related industries. Questions of a "How-To" nature by persons not involved in the electrical industry will be removed without notice.

Knowledge and the practical application of the National Electrical Code is an essential part of all electrical installations. If it's important for you to understand the National Electrical Code, then look no further.
Click to expand...

The "National " in National Electrical Code is referring to the Nation of the United States of America. Because there are so many similarities, Canadians often get the same value from this forum. I'm not being xenophobic here, just pointing out that when people from other countries post in a forum based on the National Electrical Code, they should expect that the majority of readers are NOT going to know what acronyms mean from outside of North America. Please try to be clear up front in your postings and ass-u-me nothing.
 
I thought it had something to do with Tennessee.
I got a pretty good ABB Switchgear Handbook but didn't have a Tennessee code book.
 
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