And By the Way

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Moderator Post (s) for this thread: > Grounding generators and separately derived systems by Billhart on 01/11/2009 > Grounding Electrodes by Billhart on 01/11/2009 > Not True by homebild on 01/11/2009 > Required grounding Electrodes by Billhart on 01/11/2009 > I Love it when the big boys go at it!!! by Jasper on 01/13/2009 > Portable or semi-portable generators by Billhart on 01/11/2009 > Ground wire by Billhart on 01/11/2009

The NEC Code requires 25 OHM system grounding resistance.

The NEC Code does NOT prescribe just how that resistance should be achieved.

It could be from 2 grounding elctrode rods.

But it could also be from a single metallic water service pipe...

It could also be achieved via bonding/grounding to rebar in footings...but there is absolutely NO requirement for rebar to be placed in most residential footings anywhere in the US regardless of soil conditions.

The bottom line is that the Code is very broad and lenient in how one can achieve a 25 ohm resistance for grounding conductors and allows a multitude of methods to achieve the single 25 ohm end.

And none which are MANDATORY.