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  1. #1
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    Default Neutrals and grounds for sub-panel attached to the main panel bus bars

    Energized conductors in sub-panel pig tailed to romex which enters into the main panel, grounds and neutrals attached to the main panel bus bars (see photos). I have never seen this before. Talked to an electrician that said this would not be to code today however it was ok 4 or 5 years ago. He couldn't say why code was changed. The sub-panel was put in 8 years ago. Since I don't quote code I'm wondering what safety concerns may be present and if it should even go in the report.

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  2. #2
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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jim Keller View Post
    . Talked to an electrician that said this would not be to code today however it was ok 4 or 5 years ago.
    I doubt that.


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    I haven't seen one like that but in theory the grounds and neutrals are actually only bonded at the service which gives them the required single path back (unlike bonded neutrals in a downstream panel which gives multiple paths and is dangerous). I would think trying to find the ground or neutral on the main bus would be kind of a nightmare since it would be hard to trace. Jerry probably has a good reason like all circuits must terminate in the same panel or something.
    Sorry, this one is over my pay grade.


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Actually, the reverse is true - it was not per code back then, but the code wording changed and now allows it.

    BUT ... there are other issues with that setup, here are some of the first things I noticed:

    - See all those nice pretty blue ungrounded (hot) conductors? Each one needs a grounded conductor (neutral, so to speak, but they are not actually "neutrals").

    - See those nice larger black ungrounded feeders coming from the service equipment panel (looks like it is likely the service equipment panel) on the right? And see that smaller white neutral conductor with them as the feeder neutral? That could very well be too small.

    - Is that nipple metal or PVC? Either way, it needs a grounding bushing on each side, or a separate grounding conductor run from the service equipment to the other electrical panel to the left.

    - See that nipple packed full? There is no space in there to pull all those grounded (neutral) conductors.

    Now to the service equipment panel on the right:

    - See all those conductors under that lug with the white neutral conductor? You shouldn't be seeing them there.

    - Besides just being a rats nest in there, there are a lot of white conductors on the right side which look to be going to breakers (and the photo gets fuzzy zooming in, but I don't see any test/reset buttons which may justify some of them).

    - Are those conductor on the right going to breakers which look to be bare copper (can't tell from the fuzziness), or are they insulated and brownish in color?

    - Looks like there are two white grounded (neutral, but not neutrals) conductors in the same terminal on the left.

    - Did I mention the rat's nest already? Stops one from seeing much (which makes the report shorter).

    Jerry Peck
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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Dom D'Agostino View Post
    I doubt that.
    Doubt that I talked to an electrician or doubt what he said?


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jim Keller View Post
    Doubt that I talked to an electrician or doubt what he said?
    Sorry to be vague, I doubt that install was ever allowed or compliant.


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jerry Peck View Post
    Actually, the reverse is true - it was not per code back then, but the code wording changed and now allows it.

    BUT ... there are other issues with that setup, here are some of the first things I noticed:

    - See all those nice pretty blue ungrounded (hot) conductors? Each one needs a grounded conductor (neutral, so to speak, but they are not actually "neutrals").

    - See those nice larger black ungrounded feeders coming from the service equipment panel (looks like it is likely the service equipment panel) on the right? And see that smaller white neutral conductor with them as the feeder neutral? That could very well be too small.

    - Is that nipple metal or PVC? Either way, it needs a grounding bushing on each side, or a separate grounding conductor run from the service equipment to the other electrical panel to the left.

    - See that nipple packed full? There is no space in there to pull all those grounded (neutral) conductors.

    Now to the service equipment panel on the right:

    - See all those conductors under that lug with the white neutral conductor? You shouldn't be seeing them there.

    - Besides just being a rats nest in there, there are a lot of white conductors on the right side which look to be going to breakers (and the photo gets fuzzy zooming in, but I don't see any test/reset buttons which may justify some of them).

    - Are those conductor on the right going to breakers which look to be bare copper (can't tell from the fuzziness), or are they insulated and brownish in color?

    - Looks like there are two white grounded (neutral, but not neutrals) conductors in the same terminal on the left.

    - Did I mention the rat's nest already? Stops one from seeing much (which makes the report shorter).
    Thanks for the reply Jerry but maybe you're not understanding my question. I would think that the way that this should have been done was to run the 2-wire
    with ground
    romex into the sub-panel and correctly attach the hot wire to the breaker, the grounded wire to the neutral bus bar (not bonded to the panel) and the grounding wire to a bus bar bonded to the panel. Then the black
    feeders along with the properly sized neutral and ground coming from the service equipment panel would be brought through the nipple to the sub-panel. I also understand that all the other wires shouldn't be on the neutral lug, that it's a rats nest, and that there are 2 places where neutrals are doubled under the same lug on the bus bars. Sorry about the quality of the photos. The bare wires that look like they are going to breakers are actually going to a bus bar on the right side of the main panel. There is one on the right and there is one on the left and they are bonded. I appreciate the input on all of the things wrong with the panels but my question was just regarding the neutrals and grounds for the sub-panel being terminated in the main panel on the main panel's bonded bus bars. Are you sure that this is allowed?



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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jerry Peck View Post
    Actually, the reverse is true - it was not per code back then, but the code wording changed and now allows it.

    BUT ... there are other issues with that setup, here are some of the first things I noticed:

    - See all those nice pretty blue ungrounded (hot) conductors? Each one needs a grounded conductor (neutral, so to speak, but they are not actually "neutrals").

    - See those nice larger black ungrounded feeders coming from the service equipment panel (looks like it is likely the service equipment panel) on the right? And see that smaller white neutral conductor with them as the feeder neutral? That could very well be too small.

    - Is that nipple metal or PVC? Either way, it needs a grounding bushing on each side, or a separate grounding conductor run from the service equipment to the other electrical panel to the left.

    - See that nipple packed full? There is no space in there to pull all those grounded (neutral) conductors.

    Now to the service equipment panel on the right:

    - See all those conductors under that lug with the white neutral conductor? You shouldn't be seeing them there.

    - Besides just being a rats nest in there, there are a lot of white conductors on the right side which look to be going to breakers (and the photo gets fuzzy zooming in, but I don't see any test/reset buttons which may justify some of them).

    - Are those conductor on the right going to breakers which look to be bare copper (can't tell from the fuzziness), or are they insulated and brownish in color?

    - Looks like there are two white grounded (neutral, but not neutrals) conductors in the same terminal on the left.

    - Did I mention the rat's nest already? Stops one from seeing much (which makes the report shorter).
    Quote Originally Posted by Dom D'Agostino View Post
    Sorry to be vague, I doubt that install was ever allowed or compliant.
    I agree with you Dom. I talked with an electrician buddy over the phone and perhaps he wasn't correctly visualizing what was going on.


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    The OP is asking if the hots can terminate in one panel while the neutral s remain in the service panel.

    All answers based on unamended National Electrical codes.

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jim Port View Post
    The OP is asking if the hots can terminate in one panel while the neutral s remain in the service panel.
    Thank you Jim

    That part i addressed, but missed in the original question - I thought the original question was about the pigtails in the service equipment panel.

    To expand on the one part of my reply pointing that out ad an issue - wherever a hot ungrounded conductor goes, the associated grounded conductor needs to go also.

    Doing thst part of what was shown in the photo was never allowed by code.

    The grounding conductors, however, are different as they serve a different purpose - given all else being done correctly (and it wasn't)..

    Jim will correct me if I am incorrect on this, but ... IF ... thst big "if" ... the two panel enclosures were properly bounded together (and they are not), then the grounding conductors could terminate in the service equipment panel while the hot and neutral (matching pair of the circuit) were pigtailed off to the other panel.

    As wired - the left panel is not properly grounded to the right panel, and ... ALL of the current from ALL of the circuits must use the one white grounded feeder conductor path back to the panel on the right. That one white grounded feeder conductor is only intended to carry any unbalanced current in the feeders.

    There are also other issues with that, one being the magnetic fields created by the ac current in those blue hit conductors with no cancelling magnetic fields from the white grounded conductors which aren't there.

    Last edited by Jerry Peck; 04-06-2019 at 06:25 AM.
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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jerry Peck View Post
    Thank you Jim

    That part i addressed, but missed in the original question - I thought the original question was about the pigtails in the service equipment panel.

    To expand on the one part of my reply pointing that out ad an issue - wherever a hot ungrounded conductor goes, the associated grounded conductor needs to go also.

    Doing thst part of what was shown in the photo was never allowed by code.

    The grounding conductors, however, are different as they serve a different purpose - given all else being done correctly (and it wasn't)..

    Jim will correct me if I am incorrect on this, but ... IF ... thst big "if" ... the two panel enclosures were properly bounded together (and they are not), then the grounding conductors could terminate in the service equipment panel while the hot and neutral (matching pair of the circuit) were pigtailed off to the other panel.

    As wired - the left panel is not properly grounded to the right panel, and ... ALL of the current from ALL of the circuits must use the one white grounded feeder conductor path back to the panel on the right. That one white grounded feeder conductor is only intended to carry any unbalanced current in the feeders.

    There are also other issues with that, one being the magnetic fields created by the ac current in those blue hit conductors with no cancelling magnetic fields from the white grounded conductors which aren't there.
    Thanks Jerry


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    By all my typos, you can tell I was typing on my phone.

    I'm surprised that autocorrect (or, as Jim said in another post 'car correct' for using speech recognition) didn't correct some of them (or mess them up even more).

    Jerry Peck
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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jerry Peck View Post
    To expand on the one part of my reply pointing that out ad an issue - wherever a hot ungrounded conductor goes, the associated grounded conductor needs to go also.
    Jerry & Jim P,

    So, if there was a single larger groundED conductor that matched the size of the ungrounded feed conductors between the service equipment an (but no grounded branch conductors between the two), would that address that part of the problem or does it actually need 12 grounded branch circuit conductors to match the 12 ungrounded?

    Is the issue that one teeny conductor is potentially carrying all of the amperage? Or,
    Is the issue the unmatched magnetic fields (is there a code)? Or,
    Is the issue a combination of the two?

    Quote Originally Posted by Jerry Peck View Post
    - Besides just being a rats nest in there, there are a lot of white conductors on the right side which look to be going to breakers (and the photo gets fuzzy zooming in, but I don't see any test/reset buttons which may justify some of them).
    I believe on that style of service equipment, there are two grounded terminal bars, one on each side, just below the circuit breaker terminals. Those white wires that you refer to might be going to the right side grounded terminal bar.

    More pics would certainly help. Particularly of the service equipment (hint-hint Jim K).

    Just looking for more knowledge.

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    The more I think about this, the more confused I get.

    I cannot see why the groundED conductors need to go to the added panel (other than because of the aforementioned mysterious magnetic fields). The grounded conductors are connected to the grounded terminal bar in the service equipment. They would be completely isolated in the newer panel, no matter what.

    The only difference is that the neutral current would be routed to the newer panel through the branch conductors and then the balance would go back to the service equipment via the grounded feeder. It seems to me that no matter what happens, it all ends up back at the service equipment.

    What if each ungrounded conductor (similar to Jim K's pic with no grounded conductors) was separated into its own conduit? Would this address the magnetic field issue?

    Is there a book or document that I can read to bring me up to speed on this subject?

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    300.3(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 (B)(4).
    (1) Paralleled Installations. (not typing it as it is not applicable to this discussion)
    (2) Grounding and Bonding Conductors. (read it, too much to type)
    (3) Nonferrous Wiring Methods. (read it, too much to type)
    (4) Column-Width Panelboard Enclosures. (not typing it as it is not applicable to this discussion)

    Additionally, a slight twist could be applied and:

    NEC Definitions:


    - Grounded Conductor. A system or circuit conductor that is intentionally grounded.


    - Neutral Conductor. The conductor connected to the neutral point of a system that is intended to carry current under normal conditions.


    A typical 120 volt ac branch circuit has an ungrounded conductor (i.e., 'the hot conductor') and a grounded conductor (i.e, by definition, the grounded conductor could also be referred to as a 'neutral conductor' as the grounded conductor is also connected to the neutral point of the system at the service equipment).


    - Article 200
    - - Use and identification of Grounded Conductors
    - - - 200.4 Neutral Conductors. Neutral conductors shall be installed in accordance with 200-4(A) and (B). Neutral conductors shall not be used for more than one branch circuit, for more than one multiwire branch circuit, or for more than one set of ungrounded feeder conductors unless specifically permitted elsewhere in this code.

    But I'd go with 300.3(B) first.

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    I'll respond to one part of the original question, just about the safety issues associated with running hots without returns. Yes, it is one of the violations, and when I see ignorant violations I get concerned about the likelihood of other there being screwed-up items, out of sight. However, one of the biggest concerns with not keeping conductors of a circuit together is a choke effect impairing the operation of overcurrent devices. In this case, the black feeders plus blue branch circuit conductors may serve more like switch legs, unimpaired by that particular issue.


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    The sub-feed breaker in the panel on the right side supplied the sub-fed panel on the left. The two phase conductors from that breaker should have been accompanied by an appropriately sized neutral from the neutral bus and a appropriately sized ground conductor from the ground bus routed to the N & G buses in the sub-fed panel. These buses should not be bonded in the sub-fed panel.

    The NM (Romex) circuits should not be spliced within the main panel. They should have been routed into junction boxes on the exterior of the main panel and appropriate circuits (conduit & conductor or flex...) routed to the sub-fed panel. I could not see if the NM was protected where it entered above the panel, but it should have been........


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by David Montague View Post

    The NM (Romex) circuits should not be spliced within the main panel. They should have been routed into junction boxes on the exterior of the main panel and appropriate circuits (conduit & conductor or flex...) routed to the sub-fed panel. I could not see if the NM was protected where it entered above the panel, but it should have been........
    Please state why you feel this way. Splices in a panel are specifically allowed by the code.

    All answers based on unamended National Electrical codes.

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    I see info here crawling all over the place, but nothing yet that says the sub panel (yep, it's in the book) can't be wired like it is.

    300.3 deals with wiring methods and prohibits the separation of the hot wire and grounded conductor from the supply to the load to prevent induction, like running the hot and neutral in separate conduits. Specifically excluded from the list of stuff in the list are panels and load centers.

    As wired, the panel acts line a switch leg where the supply and return runs through the same nipple and cancels the induction effect. The neutral in the panel doesn't do anything, no circuit uses it as a return so the neutral serving more than one circuit isn't an issue.

    The bonding of the panel is an issue.

    So, what specifically in the NEC addresses this setup and prohibits it? How deep can you dig into the morass to find it?

    As to splicing in the panel it is done all the time and the rules for doing so are outlined in the NEC. Absent a local addendum to the code is is perfectly acceptable.

    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jim Port View Post
    Please state why you feel this way. Splices in a panel are specifically allowed by the code.
    Understood. Sorry, I opined with a view of best practice on this aspect and not to the minimum laid out by current code requirements.


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by David Montague View Post
    Understood. Sorry, I opined with a view of best practice on this aspect and not to the minimum laid out by current code requirements.
    I'm not even sure this is a "best practice".

    Quite often a panel gets replaced due to to being obsolete or not being large enough for new loads to be handled. Required cable bending space requirements in new installations often exceed what the old panels had and so spacing in the new panel will require the original circuits be extended. Adding less than a foot to a circuit in most cases is infinitely simpler than adding a j-box somewhere to eliminate splicing in the panel enclosure. Either way you are adding a splice to the circuit, if that was even an issue.

    And if the panel is added as part of a remodel the possibility exists that an AFCI piece of junk will be required to be added to a circuit that was extended. This would require a neutral to be extended even if the line side was long enough.

    The fill rules are pretty generous regarding how much room can be taken up by splicing. With things like WAGO type connectors the space used by a splice takes up even less room. Panels need to be functional, not pretty. And "not pretty" doesn't necessarily mean bad workmanship.

    In residential wiring, best practice is an installation that does the job the customer needs at the most reasonable cost as long as code requirements are met. If the panel splicing is not a "best practice" in your view, or someone else's who has that opinion and is spreading it around, I'd invite you (or "them") to do some bidding on resi work where adding splices in the panel is used as an alternative to adding a bunch of j-boxes and running new cables from an attic or crawl space and opening walls to do so.

    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Hi all, I not new here I just rarely post and haven't posted in years. I'm an electrical contractor and I've been in the trade for 42 years.

    [QUOTE=As wired, the panel acts line a switch leg where the supply and return runs through the same nipple and cancels the induction effect. The neutral in the panel doesn't do anything, no circuit uses it as a return so the neutral serving more than one circuit isn't an issue.[/QUOTE]

    These are NOT switch legs... the supply and return are not in the same nipple, only the supply. For it to be as you state the supply and the return would have to be in the same nipple. What was done here is simply an extension of the circuit to the new panel section. Some AHJ's have varying opinions on whether or not to extend each individual neutral conductor to the new section with the majority of the AHJ's I have worked with demanding individual neutrals.

    Also having all blue wiring is not acceptable just because that's the only color the electrician had on his truck. How could you tell if these relocated circuits are not on the same phase and shared a neutral? For example: the wire that extends each circuit to the new section could have been fed from either "A" phase or "B" phase and sharing a neutral and when relocated both circuits could have been terminated on the same phase which could now potentially overload that neutral.

    Also, there is really only one panel here with two sections (Panel "A" section 1 and section 2). Section-2 of the panel should be fed with 2-phase conductors, 1-neutral and 1-ground with the neutral landing on the neutral bus which should NOT be bonded to the enclosure and the ground should terminate to the enclosure. The neutral conductor should be sized to the phase conductors or at the least sized to the size of the circuit breaker feeding the panel which appears to be 100-amp. You could probably get away with a #4 THHN copper conductor for the neutral which is one size down from the 100-amp feeders, but not a #10 as done here.

    Splicing in the panel to extend to a circuit breaker is acceptable.

    The installation as shown in the pics was only legal prior to 1897 as the first NEC code book came out that year.

    Other issues not mentioned elsewhere:

    Improper lugs in panel, the original Square-D lugs that came with this panel had stops on the backside that would not let the lug spin when tightened.


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Joe Martin View Post
    Also, there is really only one panel here with two sections (Panel "A" section 1 and section 2).
    Actually, there are two panels, each in its separate enclosure, with the right panel being (at least appears to be) the service equipment panel and the left panel not being the service equipment panel.

    If they were considered "one panel", then that would make both panels service equipment panels, and the neutrals would be required to be bonded to neutral in both panels, which, as you acknowledge, they are not - the neutral is only allowed to be bonded to ground in the service equipment panel (i.e., the right panel) and not downstream from the service equipment (i.e., not in the left panel).

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jerry Peck View Post
    Actually, there are two panels, each in its separate enclosure, with the right panel being (at least appears to be) the service equipment panel and the left panel not being the service equipment panel.

    If they were considered "one panel", then that would make both panels service equipment panels, and the neutrals would be required to be bonded to neutral in both panels, which, as you acknowledge, they are not - the neutral is only allowed to be bonded to ground in the service equipment panel (i.e., the right panel) and not downstream from the service equipment (i.e., not in the left panel).
    Jerry, I have much respect for you! You're not here because you have to be, you're here because you want help and you help many with your knowledge! You're a wealth of information!

    You're only required to bond the neutral in the first enclosure with the first means of disconnect. The second panel is fed from the first and is only there because there was not enough room in the 1st panel for the added circuits. Therefore it is an extension of the first panel. If you turn off the main breaker in the first panel it also shuts off the second panel. You can call it two panels if you like, but basically it is the same panel. Not a remote panel, not a sub-panel, a second section, section-2 or section B.

    Would you look at it differently if the first panel had feed-thru lugs that fed the second? Same thing. The way it is set up now is similar to the old split-bus panels with a main in the top section feeding the bottom section or even 2-sections in the same enclosure. Only difference is that there are two enclosures.


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Joe,

    I only was commenting on the 'two panels is one' aspect as two panels are two separate panels, even if side-by-side.

    Jerry Peck
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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jerry Peck View Post

    To expand on the one part of my reply pointing that out ad an issue - wherever a hot ungrounded conductor goes, the associated grounded conductor needs to go also.
    Not true ..... A hot ungrounded wire can be run through a conduit to a switch box, and then a switched ungrounded conductor can return through the conduit. No grounded conductor is needed.


    Quote Originally Posted by Jerry Peck View Post
    There are also other issues with that, one being the magnetic fields created by the ac current in those blue hit conductors with no cancelling magnetic fields from the white grounded conductors which aren't there.
    Again not true ..... the magnetic field from those blue conductors is being cancelled out by the magnetic field from the sub-panel feeder conductors. In essence, the breaker is a switch. The blue conductors are the "switch legs"

    Steve
    journeyman electrician


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Joe Martin View Post
    These are NOT switch legs... the supply and return are not in the same nipple, only the supply. For it to be as you state the supply and the return would have to be in the same nipple.
    Yes they are in the same nipple.... the feeder is the supply and the blue wire is the return. At any instant, current is flowing into the panel on the feeder, and leaving the panel via the blue wire.


    Quote Originally Posted by Joe Martin View Post
    Also having all blue wiring is not acceptable just because that's the only color the electrician had on his truck. How could you tell if these relocated circuits are not on the same phase and shared a neutral? For example: the wire that extends each circuit to the new section could have been fed from either "A" phase or "B" phase and sharing a neutral and when relocated both circuits could have been terminated on the same phase which could now potentially overload that neutral.
    Color coding your phase conductors is NOT required by the NEC. The only colors required are White (or natural grey) for the grounded conductor, Green (or bare) for the the grounding conductor and Orange for the "wild leg" of a center tapped delta supply

    Steve


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Looks like Steve responded to things a lot like I would have. However, I never said the wiring to the second panel was a switch leg, I said it acted like one (for the purposes of eliminating inductive heating).

    What I'm fishing for here is for somebody to post the code sections that prohibit this installation (if you ignore the bonding/ground issue). 300(B) 4 isn't the same installation, but it does have an example of where neutrals aren't required to be present in a panel and can be originated in another enclosure. This is sort of a "kick you off rejecting things for looks and posting code references" type exercise.

    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Joe Martin View Post
    The second panel is fed from the first and is only there because there was not enough room in the 1st panel for the added circuits. Therefore it is an extension of the first panel. If you turn off the main breaker in the first panel it also shuts off the second panel. You can call it two panels if you like, but basically it is the same panel. Not a remote panel, not a sub-panel, a second section, section-2 or section B.

    Would you look at it differently if the first panel had feed-thru lugs that fed the second? Same thing. The way it is set up now is similar to the old split-bus panels with a main in the top section feeding the bottom section or even 2-sections in the same enclosure. Only difference is that there are two enclosures.
    Joe, with all respect for your experience, while we're agreed as to the manifold violations, IMO because the lefthand panel does not meet the definition of a service panel it is technically a subpanel whether is it fed from the first by a chase nipple, a short nipple, a wireway, open conductors entering through loom, or 50 ft of EMT.


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Question: Can I create a split panel, by placing one panel above another, carry the hots top-to-bottom, but only one bonding wire for the neutral/ground?
    Electrically yes!
    If right panel is bonded, the white wire serves to trip either of the two upstream breakers should the left panel become energized.

    Separately: If a very tall panel has neutral and ground bars, across the top, can a circuit come in from the top terminating the white and ground near the top, while the hot continues, say, 3 feet, all the way to the bottom?
    (This is meant to address the magnetic field issue.)

    The left panel, as Joe Martin mentioned, is acting as a split-panel, the lonely white would carry only fault current.

    Best practices say the two panels should be bonded. The question of the missing whites could be relevant if the separation, between panels, was significant, but only under extreme scenarios of greatly imbalanced loads.

    Not sure if 312.8 (A) is relevant.
    If the coupler is metallic, I do not see an electrical or safety issue, that leaves the text of the code.
    That which is not prohibited is permitted.

    P.s.: a case could be made that the white wire serves no purpose.

    Last edited by Frank Belluccia; 04-29-2019 at 12:12 PM.

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Frank Belluccia View Post
    Question: Can I create a split panel, by placing one panel above another ...
    "Can" You? If physically possible, yes, you "can".

    But you are not allowed to.

    You would still have two separate panels.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Recent discussion on Mike Holts forum.

    https://forums.mikeholt.com/showthread.php?t=197930

    All answers based on unamended National Electrical codes.

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Jerry Peck View Post
    Thank you Jim

    That part i addressed, but missed in the original question - I thought the original question was about the pigtails in the service equipment panel.

    To expand on the one part of my reply pointing that out ad an issue - wherever a hot ungrounded conductor goes, the associated grounded conductor needs to go also.

    Doing thst part of what was shown in the photo was never allowed by code.

    The grounding conductors, however, are different as they serve a different purpose - given all else being done correctly (and it wasn't)..

    Jim will correct me if I am incorrect on this, but ... IF ... thst big "if" ... the two panel enclosures were properly bounded together (and they are not), then the grounding conductors could terminate in the service equipment panel while the hot and neutral (matching pair of the circuit) were pigtailed off to the other panel.

    As wired - the left panel is not properly grounded to the right panel, and ... ALL of the current from ALL of the circuits must use the one white grounded feeder conductor path back to the panel on the right. That one white grounded feeder conductor is only intended to carry any unbalanced current in the feeders.

    There are also other issues with that, one being the magnetic fields created by the ac current in those blue hit conductors with no cancelling magnetic fields from the white grounded conductors which aren't there.
    Jerry

    I'm not following what your saying in paragraph 6 of your post. None of the current flowing through the breakers in that left hand panel is going to return to the right hand panel on that white colored conductor between the 2 panels. It will come into the left hand panel on the two energized feeder conductors and return to the energized conductors of the branch circuits in the left hand panel on the individual blue wires.

    With all of the current going to and coming from that left hand panel going through the same nipple I cannot see any impedance problem either. The magnetic fields created by the currents in the feeder conductors and in the energized branch circuit conductors will cancel each other out.

    There is one panel arrangement were this separation of the energized and grounded current carrying conductors is done all the time. that is in the special panels that are narrow enough to fit inside the flanges of an I Column. Those panels are listed as an assembly though and the only place I have ever seen them is in industrial facilities.

    --
    Tom Horne


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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    See how quickly you can get to the point of what I'm quoting?

    Quote Originally Posted by THOMAS HORNE View Post
    Jerry

    I'm not following what your saying in paragraph 6 of your post.
    Tom,

    And I'm not going to bother reading my way down to there when you could have considered us readers and just posted the part you are referring to as I've been telling you.

    When I see a long quoted post - not worth reading it, especially after having explained to that poster the etiquette of this board is not to waste others time reading what is not needed in quoted posts.

    Are you on a 'post the most words in the shortest time' record hunt?

    Last edited by Jerry Peck; 08-09-2019 at 07:44 AM. Reason: speelin'
    Jerry Peck
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    www.AskCodeMan.com

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    Default Re: Neutrals and grounds for sub-panel attached to the main panel bus bars

    Quote Originally Posted by Joe Martin View Post
    ...(snip) Would you look at it differently if the first panel had feed-thru lugs that fed the second? Same thing. The way it is set up now is similar to the old split-bus panels with a main in the top section feeding the bottom section or even 2-sections in the same enclosure. Only difference is that there are two enclosures.
    I'm afraid that there is no way to shoe horn that set up into the definition of a Panelboard viz.

    "Panelboard. A single panel or group of panel units designed for assembly in the form of a single panel, including buses and automatic overcurrent devices, and equipped with or without switches for the control of light, heat, or power circuits; designed to be placed in a cabinet or cutout box placed in or against a wall, partition, or other support; and accessible only from the front."

    --
    Tom Horne


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