Interpretations of NEC 250.64(C)

[ceknight]

My current installation failed inspection today, despite being well up to what I (and previous inspectors) thought was a correct interpretation of NEC 250.64 (C). ("Grounding electrode conductor(s) shall be installed in one continuous length without a splice or joint except as permitted...." etc).

I interpret that to mean the GEC must be continuous from the grounding busbar all the way to its terminus at the 2nd electrode. No prob, that's how I've always done it, and it always passed.

Today's inspector claims that NEC 250.64(C) requires the GEC to originate at the busbar, travel continuously to clamps at both electrodes, then return to the panel and terminate at the busbar. So the GEC forms a loop from the panel to the electrodes and back to the panel.

Does anyone else interpret the rule that way he did, and if so, is one interpretation to be favored over the other?

Any help is appreciated.

Thanks,

Chris Knight

(Moderator?s Note: Edited to remove email address. If you wish to send an email message to this person, then first send a Private Message via this Forum, and ask for the email address.)

Syracuse NY

[ January 31, 2006, 05:24 PM: Message edited by: charlie b ]

 

[iwire]

Re: Interpretations of NEC 250.64(C)

The inspector is making up their own rules.

It does not even have to be continuous after the first electrode.

Here is an image from the NEC handbook that identifies the difference between a GEC and a bonding jumper.

 

[charlie b]

Re: Interpretations of NEC 250.64(C)

I agree with Bob. The article says "continuous length," not "continuous loop." Even in common conversational English, the word "length" is a one-way distance. I have a 9 foot fly rod. That does not mean that it has a "continuous length" of 18 feet!

 

[ceknight]

Re: Interpretations of NEC 250.64(C)

Bob

Thank you for your prompt reply.

The inspector (NYBOFU, not municipal) and I were both staring at the same passage in the 2005 NEC, reading it together, and he then outright accused me of reading it wrong.

Chris Knight

(Moderator?s Note: Edited to remove email address. If you wish to send an email message to this person, then first send a Private Message via this Forum, and ask for the email address.)

Syracuse, NY

[ February 01, 2006, 11:11 AM: Message edited by: charlie b ]

 

[ceknight]

Re: Interpretations of NEC 250.64(C)

Charlie

Thanks for your reply.

Then again, 18' of fly rod would make for one heck of a spey cast.

Chris Knight

Syracuse NY

Edited to remove E-mail address. Ryan_618

[ January 31, 2006, 05:51 PM: Message edited by: ryan_618 ]

 

[infinity]

Re: Interpretations of NEC 250.64(C)

Chris, as you can see from Bob's illustration the GEC is only the conductor that goes from the grounded conductor busbar to the water pipe. This conductor must be continuous. All of the other conductors are bonding jumpers and can be individual conductors interconnected to form a grounding electrode system.

 

[roger]

Re: Interpretations of NEC 250.64(C)

Along with Bob's handbook example, here's another from Mike Holt's material that is pertinent to this issue.

Roger

 

[ceknight]

Re: Interpretations of NEC 250.64(C)

I do appreciate your responses. It's pretty clear this inspector made up the continuous loop rule.

I guess the followup question is whether any harm comes from doing it the inspector's way? (Besides the lost day and the expense of the extra conductor, that is...) I'm pretty much stuck doing it his way on this job, unless a higher authority can convince him it's wrong.

Thanks,

Chris Knight
Syracuse NY

 

[infinity]

Re: Interpretations of NEC 250.64(C)

I'm pretty much stuck doing it his way on this job, unless a higher authority can convince him it's wrong.

From my perspective you need to challenge him on this. If he refuses to change his mind then a call to his boss is in order. Inspectors sometimes make mistakes. They need to have them pointed out even if it means going over their head.

 

[George Stolz]

Re: Interpretations of NEC 250.64(C)

For perspective:
</font>

• <font size="2" face="Verdana, Helvetica, sans-serif">"iwire" Bob has over twenty years experience, and has a proven track record of code knowledge.
  He has posted an image from the NEC Handbook to refute this inspector's claim.</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">"Charlie B" Charlie Beck is a Licensed Professional Engineer with BS and MS degrees in Electrical Engineering. He is also a Licensed Electrical Administrator in the State of Washington.</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">"Roger" I don't know much of Roger's credentials, but I do know he knows the code and the UL white book better than I know my own family.
  He has posted an image from Mike Holt's Grounding Vs. Bonding material. Mike Holt currently teaches seminars nationwide on the topic.</font>

<font size="2" face="Verdana, Helvetica, sans-serif">No slight to Trevor, I think I'd made my point (and I don't know how long you've been doing this either

Chris, I agree with infinity's read on this: Print out this page and hand it to the inspector. He needs to lose this misconception about grounding right now, as it's needlessly wasting the time and money of all the electricians operating under his watch.

More importantly, he's promoting wrong ideas. This chain of events needs to stop.

Be humble, be kind, be courteous: But do not relent. Please have the courage to take this to higher levels if you can. It is a disservice to our industry for wrong ideas to be accepted. Please invite him to the forum:

http://www.mikeholt.com/codeforum/ultimatebb.php

[ February 01, 2006, 07:59 AM: Message edited by: georgestolz ]

 

[pierre]

Re: Interpretations of NEC 250.64(C)

Chris

You can call Chris Gill from the NYBFU. He is the one who is now temporarily in charge of the field inspectors. His number is 212 227-3700. He will know what to do. To reiterate what has already been said, this inspector is not properly applying 250.64. If you have any problems, you can PM me and I will help.

P.S. I went to college at SU...many moooooooons ago!!!

Good Luck

 

[ceknight]

Re: Interpretations of NEC 250.64(C)

You have all been a tremendous help, I'm quite glad this predicament got me looking online for this forum. I hope to remain a member in good standing.

Today went much better -- I met with the inspector, showed him the diagrams y'all posted, and went over the rule again and explained to him (again...) that "continuous length" meant in one direction. He scratched his head, and this time did not accuse me of reading it wrong. He passed the installation.

Afterwards I asked him why he interpeted it that way in the first place, and he pulled out the NYSEG service manual (which isn't the utility jurisdiction on this job) and the diagram they provide clearly shows a loop of conductor leaving the panel, going to the grounding electrodes, and returning to the panel. It actually uses the words "loop" on the diagram.

Problem is, when you look at the note for that part of the diagram, it says to ground in accordance with NEC. So he's operating off a diagram in the utility manual instead of the actual NEC. He used that diagram to interpret the rule, rather than letting the rule make sense of the diagram.

I just double-checked the National Grid manual (they're the governing utility here), and it shows a similar diagram with the looped ground, just as the NYSEG manual did, and the fine print says "Install service ground in accordance with NEC."

So NEC gets interpreted sanely in the end, and hopefully all is well. He promised he'd research it further, but if the utility defers to NEC on this topic there's not much more he can research.

Thanks again, to all of you, for your help.

Chris Knight
Syracuse NY

 

[ceknight]

Re: Interpretations of NEC 250.64(C)

Pierre

Thanks for the contact info and the offer of help. I hope the inspector was set straight this morning, so it shouldn't come to that, but it's good to know there are resources for dealing with situations like this.

This really is the first time I've ever had a problem with an inspector, electrical or construction, I think maybe I've lived a charmed life for the last decade and the charm finally wore off.

So how many moons ago were you at SU? I moved up here for SU grad school in '87 and liked the area so much I just stayed here. Too many trout, too little time, but I keep at it when I can. Two of my kids are at SU right now, making sure I keep working instead of fishing, alas.

Chris Knight
Syracuse NY

 

[JohnE]

Re: Interpretations of NEC 250.64(C)

Great example of how to deal with a disagreement between inspector and contractor. If every inspector were humble enough to deal with the situation in this manner, we would all have a lot less to gripe about.

Presenting him your research was better than going over his head in this circumstance.

 

[infinity]

Re: Interpretations of NEC 250.64(C)

Originally posted by j_erickson:
Great example of how to deal with a disagreement between inspector and contractor. If every inspector were humble enough to deal with the situation in this manner, we would all have a lot less to gripe about.

Presenting him your research was better than going over his head in this circumstance.

I agree. At first you owe him the chance to see the error of his ways and change his mind. This was a cut and dry mistake on his part. No grey area, no 75 post arguments here about the subject. Going to his boss is IMO a last resort.


Trevor
20+ years and counting

 

[tom baker]

Re: Interpretations of NEC 250.64(C)

I hear this all the time. One wire and two clamps. One wire and three clamps, two wires and three clamps.
The GEC extends to the first GE. Then it stops. From there its a bonding jumper. You don't need two ground rods, but if you do its a bonding jumper.
This is very clear in the NEC, in 250.53 (C) Bonding Jumper. The requirement for a continuous GEC is in 250.62(C), an entirely different section.

Keep in mind with the CEE (I love that the industry already has lingo on this) in ten years we won't even know what a ground rod is.

 

[George Stolz]

Re: Interpretations of NEC 250.64(C)

Originally posted by infinity:
Going to his boss is IMO a last resort.

Yup. Looking at my post, I didn't word that very well. I was running late. It came out as though I was saying his next trip should be to the guy's boss, which isn't what I intended.

20+ years and counting

Thanks. It shows.