250.54 Supplementary Grounding Electrodes.

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hurk27

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Portage, Indiana NEC: 2008
Ok I just read this.
And what I read is when we have a water ground electrode. we add a supplementary ground rod as required by 250.53(D)(2). From what 250.54 says:

and shall not be required to comply with the electrode bonding requirements of 250.50 or 250.53(C) or the resistance requirements of 250.56
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This means it is a Supplementary Grounding Electrode and does not have to be bonded to other electrodes?
Or no resistance requirment?
Why have we been saying it does?
 
Re: 250.54 Supplementary Grounding Electrodes.

250.53(D)(2) requires a supplemental electrode.
Which could be anyone of the electrodes mentioned 250.52.
The supplementary grounding electrode in 250.54, is one installed in addition to the required ones
 
Re: 250.54 Supplementary Grounding Electrodes.

Wayne
The way I read this is that it applies to extra grounding electrodes that might be installed in addition to the required ones. As an example if you installed 10 grounding electrodes around the outside of a building and tied them to building steel you could also connect them to a EGC and be with-in code.

Don McLain
 
Re: 250.54 Supplementary Grounding Electrodes.

It would seam there is no way to use it on a grounded circuit with out bonding it to an equipment ground.
This seams to make it clear that these electrode do not have to be bond to the rest of the electrodes in the grounding system required in 250.50.
 
Re: 250.54 Supplementary Grounding Electrodes.

But that's just it!
This ground rod is the supplement to the water pipe electrode. and it even call's it a supplementary electrode in 250.53(D)(2). And why would they use the word again to discribe a extra electrode that is not even required by the nec in 250.54? I thought the NEC wouldn't give rules for somthing that's not required. wouldn't that be a design issue?
 
Re: 250.54 Supplementary Grounding Electrodes.

Wayne
It seems to me this was poor placement in the code section dealing with supplementary equipment ground electrodes and could easily be confused with grounding electrodes that are part of the grounding electrode system.

We are allowed to supplement the equipment ground with a grounding electrode but the grounding electrode to earth can not be the sole equipment ground
 
Re: 250.54 Supplementary Grounding Electrodes.

Wayne
I agree it would have made more sense to call this an equipment ground electrode
 
Re: 250.54 Supplementary Grounding Electrodes.

Ok now I think I' seing what your saying as 250.53(D)(2) goes on to say it shall comply with 250.56 which would mean 250.54 must be talking about other electrodes. but it does sound like a lot of double talk.

Boy it only gets harder. LOL :confused:
 
Re: 250.54 Supplementary Grounding Electrodes.

Yep David as putting it under III. Grounding Electrode System and Grounding Electrode Conductor
would make one think it is part of the grounding electrode system and the fact that 250.54 only permits it to be connected to the EGC makes you to think it is of the main electrode system. but then why would the NEC just permit you to connect an electrode to the EGC that is intended to be just for the EGC? This doesn't make any sense?
 
Re: 250.54 Supplementary Grounding Electrodes.

Wayne,
The code never uses the word supplementary when talking about the additional grounding electrode that is required when using a metal underground water pipe electrode. It only uses the word supplemental for this additional required electrode. Look at 250.53(B)(2). An example of a supplementary electrode is the ground rod that some designers require for parking lot light poles.
Don
 
Re: 250.54 Supplementary Grounding Electrodes.

Why is it that electrict utility companies can require additional grounding electrodes when not requierd under NEC!! and why add additional ground rods when bonding to a well line is a much better source to ground!
 
Re: 250.54 Supplementary Grounding Electrodes.

Hurk
There is a saying "Ignorance is bliss".

Not that I am saying you or anyone here is ignorant :)

You say it is only getting harder. For you, having just learned another lesson makes it easier. It is harder when one is not willing to learn and only complain about the issues we have to deal with.
Electricity and electrical work is a big responsibility and if one should choose to work in this field, than one should expect to learn what is necessary.

I have to say they do not make it easy with 250.53 SUPPLEMENTAL, 250.54 SUPPLEMENTARY. Once you know and understand it though, it is not so hard, and I bet you will not forget that now ;)

Pierre

[ March 06, 2004, 06:33 AM: Message edited by: pierre ]
 
Re: 250.54 Supplementary Grounding Electrodes.

I am with you Wayne this only became clear to me a short time ago.

250.53 Supplemental must follow all the rules of other electrodes.

250.54 Supplementary if installed, can be connected anyway you choose.

I think it is pretty easy to pass over if not paying full attention. :(

Bob
 
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