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  1. #1
    Jeff Eastman's Avatar
    Jeff Eastman Guest

  2. #2
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    Default Re: Panel in need of replacement?

    First photo:
    There is a bigger problem - all those NM cables stuffed through that one fitting in the top. That's just plain not safe (extreme derating needed), and, if they continue to be 'bundled' or have 'spacing not maintained' for 24" or more (which is likely), major major derating is needed.

    But I don't see any troublesome paint in it (granted, *NO* paint should be in it, but I don't see any which is troublesome, i.e., paint on electrical surfaces, and not even a lot on the insulation.

    Second photo:
    Looks cleaner than the first photo.

    Third photo:
    Looks cleaner than the first photo.

    Fourth photo:
    I see a little more paint from that vantage point, but for someone predisposed to reject all panels with any contamination (that'd be *me*), I think that one would be allowed to skate by ... it's not *clean* like it should be, but it's not *bad* either ...

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

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    Default Re: Panel in need of replacement?

    Quote Originally Posted by Fritz Kelly View Post
    Also, does it matter that the restriction / bundling is for only about 1/2 inch of length as opposed to a 20 foot conduit stuffed full?
    I'm wondering because I see this quite a bit.
    As Jerry said, if the bundling is longer than 2 feet, derating is needed. Depends on number of current-carrying conductors as to how much adjustment is made. This is found in the 2006 IRC at E3605.3 Adjustment factor for conductor proximity.

    "There is no exception to the rule that every rule has an exception." -James Thurber, writer and cartoonist (1894-1961)
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  4. #4
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    Default Re: Panel in need of replacement?

    Quote Originally Posted by Fritz Kelly View Post
    When you talk about derating in a situation like that, do they consider the actual load or the conductor & breaker size?
    Neither. It's taken off the rating in the table, based on the insulation temperature rating.

    First, when run into the attic, you take the ambient temperature derating (which is why NM-B is made now instead of NM - the conductor insulation has a higher temperature rating to compensate for the higher temperatures in attics ... many years ago no one thought about that, then starting about 15 years ago they did, so the change was made to raise the rating on the NM-B such that, when derated for attic temperatures, it was still acceptable and equivalent to the NM before derating.

    Now, with bundling, you need to make an additional derating, 4-6 current carrying conductor (2-3 2 conductor NM cables) is derated to 80%, 7-9 current carrying conductors (4 2 conductor NM cables) is derated to 70%, 10-20 current carrying conductors (5-10 2 conductor NM cables) is derated to 50%, then it just gets worse.

    Also, does it matter that the restriction / bundling is for only about 1/2 inch of length as opposed to a 20 foot conduit stuffed full?
    Yes, and this gets touchy.

    Everyone in the know (who reads code) knows that the magic length is 24", up to 24" and no derating is needed, longer than 24" and derating is needed.

    What if you have 2 20" long bundles or lack of maintaining spacing? Yes. According to most of the electrical experts, and, according to the code's precise wording ... but this is a gray area for some.

    But ... this is the real kicker and gray area which causes great consternation among professionals who know: When done like in your photo, even if only through a double top plate thickness, yeah, that can cause a hot spot and should be derated ... should ... be, not shall be. The code has not caught up with this yet and many experts are not committed to this problem ... yet. BUT ... every year more and more are, and this is discussed more often. It is an acknowledged problem, it's just that the code does not prohibit it specifically, unless ...

    You go back to the 2 20" long bundles and work that out, what about a 6" long bundle of many, many conductors (like in your photo) *combined with* all the other 'bundles' and 'lack of maintaining spacing' through the runs? Hmmm ... food for thought there.

    As best I could count, there are about 20-23 white conductors, which means 40-46 current carrying conductors (black and white added together), that means that bundle would need to be derated to 35% of their rating. A #12, 25 amp rating, derated for ambient attic back down to about 20 amps, would be derated down to about 7 amps.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  5. #5
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    Default Re: Panel in need of replacement?

    There's a lot of 20 amp breakers in there. What's that system rated for. Service entrance looks to be aluminum. Seems like maybe more going on than already mentioned.

    Eric Barker, ACI
    Lake Barrington, IL

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    Default Re: Panel in need of replacement?

    Quote Originally Posted by Jeff Eastman View Post
    Jerry, Well, Geez. I see the wires bundled all the time through one fitting like that old and new construction. I have not been writing them up as a defect. Since I don't know if the wires contact each other for more than 24 inches would would you recommend to put in the report? "Wires bundled together through fitting creates a safety hazard. Derating needed?"
    Or address it this way with that as a side note:

    NM cables bundled together going up through a single fitting, EACH NM cable is required to be in a proper NM cable clamp (which may be rated for 2 NM cables in some cases), this results in a large bundle of conductors (approximately 40-46 in this installation) and derating is needed for safety, that derating would derate those conductors down to only about 7 amps. HOWEVER, when making the PROPER CORRECTION of installing separate clamps, this problem will also be corrected and become moot, as there will not be more than 2 NM cables in any one clamp. When this work is done, have electrical contractor make sure that no bundling is present in the area being re-worked or visible during that re-working.

    You've now noted the derating problem, but also pointed out the overriding (and causing) problem - that the NM cables were not installed in the proper clamps they are required to be installed in, and then pointed out that correct *the* problem will also correct the bundling problem, making the bundling problem go away at that same time.

    Now, when the electrician calls and gripes about 'WELL ... those were not bundled for 24 inches ... ', you can interrupt them and point out that, 'if the NM cables had been installed LIKE THEY SHOULD HAVE BEEN, neither of you would be talking about derating, would we?' ... There really is not much they can say at that point. 'Besides,' you continue (after a brief silence) 'now that you have or are correcting them and installing the NM cables in their own clamps you only have 1 or 2 NM cables together in one clamp - right?'

    Then you wait for his/her response. Which really can be nothing other than 'Right.'

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

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    Default Re: Panel in need of replacement?

    Jeff,

    You've missed the point - that derating condition is caused by *improperly installed NM cables*, see my other post.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

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    Default Re: Panel in need of replacement?

    I think Jeff meant that the cables are all routed through the 2" nipple at the bottom right, much like the first setup.

    Jim Robinson
    New Mexico, USA

  9. #9
    Richard Rushing's Avatar
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    Default Re: Panel in need of replacement?

    As far as the original post/ question, I can't see where this would possibly warrant replacement... or mentioning for that matter.

    rr


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    Default Re: Panel in need of replacement?

    Quote Originally Posted by Jim Robinson View Post
    I think Jeff meant that the cables are all routed through the 2" nipple at the bottom right, much like the first setup.
    That is exactly what I was referring to.

    *EACH* (or, at most, two) NM cable should be in its own clamp (or, at most, two NM cables in each clamp).

    *NOT* run through a large nipple like that.

    The NM clamps do two basic things: 1) serve as a strain relief, 2) serve as a support and securing point to hold the NM cables within the knock outs or openings the NM cables pass through.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  11. #11
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    Default Re: Panel in need of replacement?

    Another problem with the practice of passing many wires through a bushing is that there is no strain relief for the wires.

    "Strain relief" is what prevents a tug on the wire from making it to where the wires actually connect to the terminals. Every electrical connection needs some sort of strain relief- unless it's just not possible to tug the wire without first taking something apart.


  12. #12
    William Mize's Avatar
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    Default Re: Panel in need of replacement?

    I do not see a main breaker, is there one and I do not see it or is this panel wired as a "sub".

    Dang you guys anyway just when I think I know something you show me how much I do not know.

    willie


  13. #13
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    Default Re: Panel in need of replacement?

    Quote Originally Posted by William Mize View Post
    I do not see a main breaker, is there one and I do not see it or is this panel wired as a "sub".
    From post #7: "This is NOT the service equipment panel. Downstream panel in the laundry room."

    "There is no exception to the rule that every rule has an exception." -James Thurber, writer and cartoonist (1894-1961)
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  14. #14
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    Default Re: Panel in need of replacement?

    Quote Originally Posted by John Steinke View Post
    Another problem with the practice of passing many wires through a bushing is that there is no strain relief for the wires.
    Finally!

    Something John and I agree on.



    Me (in preceeding post): "The NM clamps do two basic things: 1) serve as a strain relief,"

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
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