Earthing arrangement.

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Miguel c said:
What kind of Earthing arrangement does the NEC mostly implement? Is it TN-C-S? Or TN-S TN-C?
What article in the NEC makes reference to those?
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The NEC does not use those terms anywhere. In fact they are not really know by very many in the US, and I don't understand those terms and have no reason to learn them as we don't use them.

In general from the utility to the service equipment there will be the ungrounded conductors and the neutral conductor. The utility will connect the neutral to earth at their transformer. At the service equipment, we will connect the neutral to earth a second time, but all equipment will be supplied with the ungrounded conductors, the neutral conductor, and and equipment grounding conductor. The neutral and equipment grounding conductor are never connected together again on the load side of the service equipment.
The grounding requirements are found in Article 250.
 

Earthing system

en.wikipedia.org en.wikipedia.org
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Looking up your terms and deciding to educate myself to help you... The NEC advises to provide grounding "Earthing" based on various conditions. As Don pointed out in the end of his statement... Article 250 will help you.... but good luck wrapping your head around all of it because many of us still get confused about what to do and when. hahaha.
 
Per the classic Overcurrents and Undercurrents by Earl Roberts, the US uses a TN-S, some older dryers are TN-C, and like Don G, I don't know what that means, but the book explains its a uni-groudned neutral. Your best explanation is NEC Article 250. And as pointed out, there is a lot of confusion on grounding and bonding. Most grounding is actually bonding.
 
TN-C-S as a whole by far.

TN-S when the system is not supplied by a utility, ie transformer on the customer's premises.

TN-C was allowed under special conditions such as stoves and dryers.

IT is allowed by the code, but predominately found only on older industrial installations.

TT is absolutely forbidden.
 
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