Concentric KO's

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nathan1

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when working on the load side of the service must you use a grounding locknut when you use a concentric ko for a 1" emt conduit run?
 
Re: Concentric KO's

Without a code book in front of me I would say it would depend on the voltage of the system, a 277/480 system has more strict rules than a lesser voltage. For the higher voltages I belive that they would require bonding as required in the first 3 methods of bonding the service raceway.
 
Re: Concentric KO's

Art 250
Part V Bonding

250.92(B) Method of Bonding at the Service.
(1)-(4)
250.96(A) Bonding of Other Enclosures.
250.97 Bonding for Over 250 Volts.

Ken's memory is pretty good :) , here are some references.
 
Re: Concentric KO's

Just last week the inspector made me install a bonding bushing on a 1/2" conduit on the load side citing concentric knockouts. It was a residential 120/240 service. I admit it is a good idea but after reading those articles it doesn't look like it is required.
 
Re: Concentric KO's

It is a good idea, but certainly not required. That is one reason why I suggest to contractors and electricians to have the code book available on the job, in case they want to "discuss" it with the inspector :) .

Remember one thing about inspectors. They may have learned a particular method of installation and they are thinking it is a requirement. You show them the code, and you will help them and every electrician after you.

The old saying " theres more than one way to skin a rabbit", is very prevalent in our industry.

[ March 08, 2005, 10:29 PM: Message edited by: pierre ]
 
Re: Concentric KO's

Originally posted by johndeereman:
This why it should be required that the AHJ should put the Code Art. to back up his/her requirements. ;)
I'm an electrician (electrical contractor) and a Combination Building Inspector (ICC Certified Combination Building Inspector - bldg., plumbing, mechanical, electrical).

As an electrician I always carry the NEC with me for 'discussions' with an inspector. I feel as an electrician, not only should I know my trade, I should be code knowledgable...at least well enough to do an installation 'per code' and support my work should an inspector question me.

As an inspector I find it a bit hypocritical for a contractor (who is supposed to know his trade code and do his work code compliant) to want me to write down the particular code section when writing a correction notice. I am always willing to listen to a contractor's dispute and go over the particulars with him. I carry several handouts with me (photocopies from UL white book, etc.) discussing some of the recurring violations I see. If he's friendly and shows an honest interest in learning or wanting to better understand the correction notice I'll pull out my code book or NEC handbook and show him the particulars. Or if I'm running short on time I'll suggest he can come in the office and we'll open the code books. But if he really wants me to write down the code section on the spot and play hard ball, then I'm more than willing to do an inspection 'by the book'. I tell him I'm willing to radio in and ask other inspectors to cover the rest of my schedule and I'll walk over to my car and pull out all four code books and I'll do a complete, thorough, indepth inspection with all my code books out; of course there will be a reinspection fee for his violations.

As an electrician and an inspector I'm well aware of contractor's legitimate ire at being cited for nonexistent, 'wish-list' code violations....but I'm also aware very, very few contractors (electricians or any trade) have seen a code book since the day they took their certification exam (like 20 years ago!!).

Obviously, the above observation does not apply to this forum group...no, I'm not being sarcastic...unfortunately, you guys make up a very small percentage of tradesman.

Several times a week I hear, "I've been doing it that way for 20 years...."...and I have to respond with, 'I have no doubt you have sir, unfortunately the codes change every 3 years and this particular code item went into effect about 17 years ago....you might try studying a code book every 5 years or so.'

Just as a side note: Generally, I find that most combination inspectors are weakest on the electrical code, and if they have a fault it's they'll let most violations get by rather than the other way around.
 
Re: Concentric KO's

Dana When you write a tag for a violation you are writing a warning ticket just like a law officer, DNR, or other officer of the law. Most states a court of law will not Honor a ticket if the reference to the law (code section) that has been violated is not on the ticket. So you state most likely has a law like my state(Indiana) that requires you to put the code that has been violated on the ticket. And yes the electrician should know the code but sometime there is nothing you can do about other than tag his jobs when he commits a violation.

P.S. also how could I dispute a tag with no code reference? I would not have any idea what the inspector is using to cite the violation. Sometimes it's clear but other time it's not clear where he/she's coming from? Many times the we are not on the job when the inspector is there so I can't just ask him. and trying to contact them when your out in the field is imposable around here as they don't give out their cell number probably for good reason. :D

[ March 09, 2005, 10:42 PM: Message edited by: hurk27 ]
 
Re: Concentric KO's

I have all my inspectors cells or nextel #`s.When there is a tag I disagree with I call them on it.If valid we make the correction if not well just because they would like it that way,or I`d do it this way doesn`t hack it.I have posted about a few AHJ`s that are well(moderators will edit the word)but when i call them and require them to show me either they do or repeal the tag :D
 
Re: Concentric KO's

Originally posted by hurk27:
P.S. also how could I dispute a tag with no code reference? I would not have any idea what the inspector is using to cite the violation. :D
Hurk - I disagree with this.

If I wrote a correction notice saying 'the ground rod clamp [being used] is not rated for earth contact - use clamp rated for earth contact' (no code reference)...you are saying you wouldn't know what the correction is about and therefore have a legitimate dispute about the correction notice.

If I did cite a code section, 110.3(B), then it is becomes clear to you? Most of these contractors are going to Home Depot and buying the cheapest clamp they can find...there is no packaging or listing information that comes with these $1.39 clamps...that code citation would require them to get a UL white or green book, look up the listing information to see that zinc clamps are not rated for earth burial.

BTW - most correction notices are for simple items the electrician just forgot to finish...didn't connect a bonding jumper, didn't put a KO seal on an unused opening...these guys don't need a code citation...it's just an 'oops'. For the good electricians the inspector is just a 2nd pair of eyes to double check they haven't overlooked something.

I find that a lot of correction notices are just a 'punch list'...I'm going through a job and the notice is really just a list of items they haven't finished up yet...I might have 3 pages of write ups and it would be too onerous on me to have to cite a code section for this punch list.

Please - I don't mean to offend electricians. What I'm saying is - I write a clear, concise correction notice - those who read the notice have a clear idea what the violation is; and I am readily available for them to have a more indepth discussion on the subject.

It just seems those who want to play hardball or demand a code citation are the very ones who don't own a code book, haven't used one in ten years (if ever) and wouldn't know what to do with one if you gift wrapped it for them.
 
Re: Concentric KO's

Originally posted by dana1028:
It just seems those who want to play hardball or demand a code citation are the very ones who don't own a code book, haven't used one in ten years (if ever) and wouldn't know what to do with one if you gift wrapped it for them.
We don't have to playing hardball to second-guess a red-tag. There are often items that are not code, that are written up on red-tags, which can't be backed up.

I would think it would be good practice, and actually be more comforting for the inspector to be able to cite a code reference: You jot down the reference, good luck having your call backfire on you. IMO.
 
Re: Concentric KO's

dana 1028, when I inspected for the state it was required that I back up my correction notices with Code Art. I was also instructed that the list of corrections were considered a legal document (just like another poster stated above). This had to be done so that in the eventuallity that for whatever reason a dispute might make it to court, the corrections had to be written accordingly in order to be fully supportable. Many of the electricians thanked me for this effort because it helped them look at the code in a different light. This is in no way meant as a reflection of the knowledge, skill, or abilities of the electrician, it is however a way to support the AHJ's call and leave subjectiveness out of the picture.
 
Re: Concentric KO's

It should be mandatory for all inspector to state the code section of the violation. That would eliminate the inspectors that don't know the code and red tag just because they don't do it that way or they like it there way.
I don't see asking for the code section to be hardball at all. This is what inspectors get paid for. The code section should be right at your finger tip don't you think and if you keep red tagging for the same things you should not have to even look it up.
 
Re: Concentric KO's

I have a question about the original post, is the conduit being used as the equipment ground?
are there concentric KO"S at both ends of the run? 250.96 (A) applies to that conduit also, with or without an equipment ground, will that concentric KO clear a fault in the case of a ground fault on the conduit.
 
Re: Concentric KO's

Concentric or eccentric KOs are not listed in the Art that you listed but it would'nt hurt to install bonded bushing or locknut if you wanted to. Keep in mind that the code is only a min. requirement.
 
Re: Concentric KO's

250.96 (A) also says it must be able to counduct
safely any fault current likely to be imposed on them, that is the minimum, will that concentric KO clear a fault, without additional bonding.
 
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