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Thread: Bonding issue

  1. #1
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    Default Bonding issue

    I'll try to post a pic later, but here's the scenario:
    Condo has a separate 100 amp breaker mounted just above the panel board. Only the two feeder wires enter and exit this breaker. The neutral and ground wires enter the lower panel board and have separate connection points. Is this OK? Will the upper breaker box be bonded to the lower if conduit houses the feeder wires (which I haven't verified yet)? The 100 amp breaker IS NOT the service by the way. Thanks for the help.

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  2. #2
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    Default Re: Bonding issue

    Quote Originally Posted by Dave Mortensen View Post
    Condo has a separate 100 amp breaker mounted just above the panel board. Only the two feeder wires enter and exit this breaker. The neutral and ground wires enter the lower panel board and have separate connection points.

    The 100 amp breaker IS NOT the service by the way. Thanks for the help.
    Okay, that last sentence clarifies what my first question was going to be ... this is what you should have:
    - service entrance conductors go to the service equipment (both of which are elsewhere), the service entrance conductors are allowed to have an uninsulated neutral, and the neutral and ground is allowed to be one and the same, all service conductors must be run together (basically speaking here)
    - feeder conductors go from the service equipment to the (for lack of a better term) "Unit Main" disconnect in the condo unit; the feeder conductor neutral is required to be insulated and a separate ground is required; all feeder conductors must be run together
    - - the above means that the two hot conductors, the one neutral conductor, and the one ground conductor must run with each other to the "Unit Main", the hot conductors would be terminated at the "Unit Main" disconnect, the neutral conductor would be terminated at a neutral terminal bar, and the ground conductor would be terminated at a ground terminal bar
    - feeder conductors, as stated above, would also run from the "Unit Main" down into the panel below

    Hope that helps.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
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  3. #3
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    Default Re: Bonding issue

    I've attached a photo showing the feeder wires entering the lower panel board at the bottom, exiting at the top and returning at the top after going through the breaker. I misspoke when I said only the feeder wires enter and exit the upper panel.

    Jerry: "the above means that the two hot conductors, the one neutral conductor, and the one ground conductor must run with each other to the "Unit Main", the hot conductors would be terminated at the "Unit Main" disconnect, the neutral conductor would be terminated at a neutral terminal bar, and the ground conductor would be terminated at a ground terminal bar"

    So if I'm following this right, all the feeder wiring needs to be installed in the upper panel and all the wiring then travels to the lower panel where it is installed like any other panel.
    Did I get that right? So it looks like this install is incorrect mostly because the NEC calls for the wiring to be installed this way, and what is the reasoning? Does it have to do with the panel boards not being bonded to one another?
    I'm going to have to convince the electrician who said it was correctly installed, thanks for the help Jerry.

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  4. #4
    Guy W Opie's Avatar
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    Default Re: Bonding issue

    This is what I see. The MLO is being fed from a meter located elsewhere, where the main disconnecting means is located. The condo owner or someone wanted a disconnecting means in the condo. This why this disconnect was installed. I have seen this before and providing that metal conduit and bonging lockrings and /or bonding bushing depending on installation are used it acceptable. If pvc conduit was used than a bonding wire is required.
    Regular lockrings or double lockrings, are not acceptable in lieu of bonding lockrings.

    When a metal service raceway terminates to an enclosure with a ringed knockout, a listed bonding device, such as a bonding wedge or bonding bushing, must bond one end of the service raceway with a bonding jumper sized in accordance with Table 250.66 [250.92(B)(4) and 250.102(C)]. If ringed knockouts are not encountered, a bonding locknut can be used instead of a bonding wedge or bonding bushing.


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    Default Re: Bonding issue

    Guy,

    Good morning. I agree with your assessment of the photos. However I disagree that this should be allowable. This is a "Gypsy", not to be denigrating to anyone, work-a-round to installing a proper main disconnect switch.

    I believe this might have been allowed one time under code, but I cannot find it any of my archived notes to myself.

    Dave: Any idea what code level this panelboard and breaker were installed under?

    Using a properly installed main disconnect switch will effectively change the grounding and bonding requirements of both the switch and the panel below it. Under 2008 NEC, the panelboard would now be required to be a four conductor feed from the main disconnect switch, not a 2 conductor feed from the breaker.

    I would also be suspect of the splices used to route the service conductors from the MLO panelboard to the breaker.

    Last edited by Donald Farrell; 03-23-2011 at 08:08 AM.

  6. #6
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    Default Re: Bonding issue

    The condo was built in 1976 I believe, so whatever code applies. I'll look up the code in the 2008 NEC that you are referring too and go from there. I guess the electrician will have to come up with the code when built and we'll begin the arm wrestling. It does sound like a "bonding" violation, is that correct?
    I did callout the splices and the electrician did repair these.


  7. #7
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    Default Re: Bonding issue

    Quote Originally Posted by Dave Mortensen View Post
    So if I'm following this right, all the feeder wiring needs to be installed in the upper panel and all the wiring then travels to the lower panel where it is installed like any other panel.
    Did I get that right? So it looks like this install is incorrect mostly because the NEC calls for the wiring to be installed this way, and what is the reasoning? Does it have to do with the panel boards not being bonded to one another?
    Correct, the neutral conductor needs to go up into, land on the neutral terminals, then back out of, the upper enclosure, which is the service equipment, and down to the panel. The grounding conductor should also go to the service equipment up on top, but could then use the metal enclosure and metal nipple down to the panel below - if the proper ground bonding busing had been used, etc.

    One of the reasons is to help cancel out eddy currents (magnetic fields in the metal enclosure which would otherwise surround the conductors), and because the neutral conductor is required to go everywhere the hot conductors go (partially for the above reason).

    However, the biggest thing I see is not the above problem of the neutral and ground conductors not running up into the upper service equipment - the biggest problem, by far, is that the two hot service entrance conductors DO run through the panel and up into the service equipment above.

    The service entrance conductors are not allowed to run through the panel, they would be required to enter into the top service equipment enclosure, land there, THEN run down into the panel.

    As you can see, the two hot service entrance conductors are spliced in the lower panel, which indicates that someone either planned wrong, something was changed, or they simply had no idea of what they should be doing, ... or ... all of the above.

    I am thinking that someone originally wired that bottom panel as the service equipment, then were told that they had too many disconnects, and re-wired it as you now see it.

    Looks like you have a myriad of other defects too: white conductors to breakers; possible ground conductor termination problems; scorch make on bottom conductor, etc.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
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  8. #8
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    Default Re: Bonding issue

    The easiest fix may be to abandon the disconnect and install a main breaker panel in place of the current MLO.

    All answers based on unamended National Electrical codes.

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    Default Re: Bonding issue

    The head Muni inspector told me the following:
    Routing the feeder wires in this fashion was never allowed and gave me the code from the NEC:
    NEC 300.3 Conductors
    (B) Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1) through (4).

    I talked with him over the phone so he may not have understood the feeders run through the lower panel. Where do I find that in the NEC?
    I spoke with the electrician who ok'd the panel and he's now going to re inspect the panel and talk to the Muni code official directly.

    Interesting note, the Muni has added (since the mid 90's) that a bonding wire must now run with any conduit, so it doesn't just rely on the conduit itself for bonding purposes.

    Jerry, you were right on about this and Jim, I think that's the solution here as well, just add the main breaker within the lower panel.

    Thanks for all the help! I'll keep you posted as to how this all turns out.


  10. #10
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    Default Re: Bonding issue

    Dave,

    There are two applicable code sections which prohibit those conductors from running through that lower enclosure to the upper enclosure, but first let's call them by the correct term: those conductors are not feeder conductors, those conductors are service entrance conductors, and service entrance conductors have more stringent rules covering them than cover feeder conductors. Feeder conductors are protected on the line end of the conductor, at the end from which they receive power, whereas service entrance conductors are protected on the load end of the conductor, which, to a certain extent, leaves the conductor unprotected.

    (underlining and bold are mine)
    - 230.7 Other Conductors in Raceway or Cable.
    - - Conductors other than service conductors shall not be installed in the same service raceway or service cable. (Jerry's note: That lower enclosure is being used as a raceway for the service entrance conductors.)
    - - - Exception No. 1: Grounding conductors and bonding jumpers.
    - - - Exception No. 2: Load management control conductors having overcurrent protection.

    - 312.8 Enclosures for Switches or Overcurrent Devices.
    - - Enclosures for switches or overcurrent devices shall not be used as junction boxes, auxiliary gutters, or raceways for conductors feeding through or tapping off to other switches or overcurrent devices, unless adequate space for this purpose is provided. The conductors shall not fill the wiring space at any cross section to more than 40 percent of the cross-sectional area of the space, and the conductors, splices, and taps shall not fill the wiring space at any cross section to more than 75 percent of the cross-sectional area of that space. (Jerry's note: This code section frequently leads to much discussion about "unless adequate space for this purpose", however, as the first part states "shall not be used as", and the standard to which panels and service equipment enclosure are listed to do not provide any space for that purpose. With no space provided for that purpose, that use is not allowed.)

    The second sentence in the code section above first: a) places a limitation of 40% fill for the allowed conductors in that enclosure (conductors not using the enclosure as a raceway); b) and if there are any taps or splices (such as extending conductors with wire nuts to reach a breaker during a replacement) then those taps and splices are not allowed to fill more than 75%.

    Neither of the last two 40% or 75% fill allowances allow for conductors which are not allowed. Just saying that, heck, I got plenty of room, does not allow the enclosure to be used as a "junction boxes, auxiliary gutters, or raceways for conductors feeding through or tapping off to other switches or overcurrent devices" - the conductor must STILL terminate in that enclosure.

    That code section is a hot button issue for those who like to make, and take, short cuts instead of doing it properly as they now must do a lot more work to do what they were going to do.

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

  11. #11
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    Default Re: Bonding issue

    Quote Originally Posted by Dave Mortensen View Post
    Jim, I think that's the solution here as well, just add the main breaker within the lower panel.
    Does not look like there is room to just add the main breaker within the lower panel, I suspect that Jim was referring to replacing that enclosure and panel with one which has a main disconnect in it, the panel will probably be taller, but would otherwise fit in the same space.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
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  12. #12
    Guy W Opie's Avatar
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    Default Re: Bonding issue

    After looking into this further I amend my previous post. This needs to corrected, either by install main disconnect in panel, changing panel etc.


  13. #13
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    Default Re: Bonding issue

    Jerry,
    I haven't verified this, but my thought was there is a main disconnect for this unit on the outside of the building with the service wires going to it. Would "feeder wires" then be going to the disconnect above? Does that change anything, or everything?


  14. #14
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    Default Re: Bonding issue

    Quote Originally Posted by Dave Mortensen View Post
    Jerry,
    I haven't verified this, but my thought was there is a main disconnect for this unit on the outside of the building with the service wires going to it. Would "feeder wires" then be going to the disconnect above? Does that change anything, or everything?
    Dave,

    That would change those conductors from being service entrance conductor to being feeder conductor, however, the following would not change:
    - the requirement that the neutral be run with the hot conductors (the neutral and ground conductor would need to be separate and the neutral isolated from ground)
    - the feeder conductors still would not be allowed to run through that enclosure and not terminate in that enclosure (i.e., not run up to the "unit disconnect"

    If those are feeder conductors, then the feeder conductors from the service equipment to the splice were likely going directly into the main lug only terminals, and there would not be a required need for the disconnect which seems to have been added and is creating the problems.

    Would that "unit disconnect" be good to have? 'Yes ... if wired properly', but 'No, not as wired'.
    -

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
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    Default Re: Bonding issue

    The electrician removed the 100 amp disconnect entirely, so no more routing through the panel. Thanks for the help!


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    Default Re: Bonding issue

    Dave,
    Lot's of good info has been provided here. You Identified the issue during your inspection and assume you made the recommendation in your report to the buyer that the panel(s) be further evaluated by an electrician. Just curious as to why you had to convince the electrician that the wiring was incorrect?


  17. #17
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    Default Re: Bonding issue

    He had already gone over and fixed other problems with the report, but neglected to do anything regarding this issue. So when I asked him about it, he said all was fine, I decided to check with the Muni electrical inspector who said it wasn't and gave me the code. Then I approached the electrician again, and he went back and removed the problem. I don't necessarily think he wasn't a good electrician, I think it has to do with what info he was given as to what he had to fix in the first place. I don't think he ever opened the disconnect panel, however he still would have seen only the two conductors leaving the lower panel, so who knows...


  18. #18
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    Default Re: Bonding issue

    Thanks Dave, what I was driving at is why get so involved post inspection. You did your job in pointing out a potential problem and recommended it be further evaluated by an Electrician. Either the client or the seller hired the Electrician to evaluate. At that point whether the Electrician agreed or disagreed with your report that would ultimately be resolved between the Electrician and the buyer/seller who hired him.

    Bob


  19. #19
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    Default Re: Bonding issue

    I was advocating for my client the buyer, who didn't really understand the problem and wanted me to follow up. Just as if I was doing a re inspection and the repair wasn't done properly, I would advise my client and the repair would have to be re done. I should clarify that the buyer asked what specifically was done to address the problem we've been discussing and wasn't satisfied with the electrician's explanation that all was well. I typically do not get so involved with an electrician's repair, but in this case I think it was justified.


  20. #20
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    Default Re: Bonding issue

    Quote Originally Posted by Dave Mortensen View Post
    The electrician removed the 100 amp disconnect entirely, so no more routing through the panel. Thanks for the help!
    What about a means to disconnect the panel? There are more than 6 throws required in the lower panel.

    All answers based on unamended National Electrical codes.

  21. #21
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    Default Re: Bonding issue

    This was a 2nd disconnect added later (for convenience?), the first being at the exterior service entrance.


  22. #22
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    Default Re: Bonding issue

    Now I understand why you went to such great lengths on the issue. Thanks for clarifying.
    Bob


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    Default Re: Bonding issue

    Quote Originally Posted by Dave Mortensen View Post
    This was a 2nd disconnect added later (for convenience?), the first being at the exterior service entrance.
    Was the cable changed to a 4 wire feeder?

    All answers based on unamended National Electrical codes.

  24. #24
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    Default Re: Bonding issue

    It might be hard to see in the pic, but a 4 wire feed entered the lower panel originally, so all he had to do was disconnect the feeder splices and re connect to the lugs. The neutral and ground stayed installed as they were.


  25. #25
    Guy W Opie's Avatar
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    Default Re: Bonding issue

    6 throw rule does not apply in this situation. If it did than every residential panel would be wrong.


  26. #26
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    Default Re: Bonding issue

    Quote Originally Posted by Jim Port View Post
    What about a means to disconnect the panel? There are more than 6 throws required in the lower panel.
    That panel is not service equipment, that is not a requirement at panels downstream from the service equipment.

    Jerry Peck, Construction / Litigation Consultant
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  27. #27
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    Default Re: Bonding issue

    Quote Originally Posted by Jim Port View Post
    Was the cable changed to a 4 wire feeder?
    The feeder is already a 4 wire feeder.

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