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Thread: sub panel

  1. #1
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    Default sub panel

    Wondered if someone could comment on a sub panel that had a 100 amp main breaker, that was fed by a 60 amp breaker from the 100 amp main panel. The wire feeding the sub panel was sufficient for a 100 amps.

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  2. #2
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    Default Re: sub panel

    Intriguing! I wonder why they would have done that. If I see something like this, I make a comment on the order of "Be aware that although the subpanel appears to be 100 amp, it will be limited to 60 due to the smaller feed in the main panel." That alerts the buyer to the fact that the subpanel will not actually handle the full 100 that it otherwise could. However, I don't see any particular danger in limiting a panel to LESS than its capability; it's when they go the other way around and put a 60 amp panel on a 100 amp breaker that I get worried.


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    Default Re: sub panel

    Quote Originally Posted by Russell Melville View Post
    Wondered if someone could comment on a ...
    .
    panel that had a 100 amp main breaker,
    .
    that was fed by a 60 amp breaker
    .
    from the 100 amp main panel.
    .
    The wire feeding the sub panel was sufficient for a 100 amps.
    Comment that nothing was wrong as you described it?

    The only comment I might make from your description is that if they changed the 60 amp breaker out to a 100 amp breaker they would have a 100 amp distribution panel there ... keeping in mind (of course) that the service equipment panel also had a 100 amp main breakers and that if 100 amps was used at the distribution panel the main breaker would likely trip too - or may trip first - and that would not be a good thing.

    In other words, replacing that 60 amp breaker with a 100 amp breaker could lead to an unexpected "lights out" situation.

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  4. #4
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    What is the 100 amp wiring method to the sub-panel? If it's cable then it's likely that the EGC is undersized according to 250.122(B).


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    Default Re: sub panel

    Here is a picture of the main panel. As I stated, the wire is not undersized.

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    Default Re: submarine panel

    I had something along those lines the other day: 100 amp service to the house, 100 amp main breaker in the service panel, also in that panel a 100 amp breaker feeding another 100 amp breaker in the remote panel. All cable sizes were correct. I believe the intent is to upgrade the service at a later date, at which time the remote panel will not need alteration.

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  7. #7
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    Quote Originally Posted by Russell Melville View Post
    Here is a picture of the main panel. As I stated, the wire is not undersized.

    If that's a standard cable feeding the subpanel the EGC is too small.


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    Quote Originally Posted by Robert Meier View Post
    What is the 100 amp wiring method to the sub-panel? If it's cable then it's likely that the EGC is undersized according to 250.122(B).
    I don't see an EGC in that picture.

    The service cable looks to be 2-2-2 with earth provided by what appears to be either a site-made conductor or two 6awg or 4awg conductors (I can't really tell from the picture).

    The feeder to the remote panel also appears to be 2awg, either in some type of conduit or as part of an AC or MC cable assembly. I can't see anything in that picture to indicate what is providing ground to the remote panel.


  9. #9
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    Quote Originally Posted by Russell Melville View Post
    Here is a picture of the main panel. As I stated, the wire is not undersized.
    Can you explain what we're looking at in this photo? There is AC cable (left) and SE cable (center) entering the top of the panel. Are either of these the service entrance conductors (I'd guess the SE cable) ? Which CB is the service disconnect? Is the AC cable connected to the 60 amp CB feeding the subpanel?




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    Default Re: sub panel

    Looks like the SE is feeding the panel based onit going into the main breaker.

    I like how they left the label on the bond screw when they installed it.

    I suspect the old metal cable feeds the original panel in the house, but there is no way to tell from the pic. If it does there may be issues with neutral and ground separtion in the other panel.

    All answers based on unamended National Electrical codes.

  11. #11
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    The cable at the left services the sub panel. It is like an old bx cable. The center cable is the service entrance.


  12. #12
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    Quote Originally Posted by Russell Melville View Post
    The cable at the left services the sub panel. It is like an old bx cable. The center cable is the service entrance.
    Since the AC cable does not contain an EGC then 250.122(B) (previously mentioned) would not apply. The only issue may be the bare neutral conductor that is spliced to the AC cable and the bonding screw.


  13. #13
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    100 amp wire on a 60 amp breaker is odd, but not a code violation, unless the 60 amp breaker terminals cannot accept wire that big. It's not legal to trim strands off a wire to make it fit. The MCB size on the sub-panel being fed by that feeder does not matter because it is only serving as a disconnect switch. The feeder in question is a manufactured cable assembly and I doubt the jacketing/flex conduit exterior would provide an acceptable ground. It was probably a legal grounding means when it was made, but not today. The acceptability of the bare neutral wire splice extention is questionable, but it is functional. A ground for that feeder is the only thing worth calling IMO.

    Last edited by Garry Blankenship; 06-02-2012 at 10:41 PM. Reason: Same word twice; deleted one.

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    It looks like the armored cable is the feed to the remote panel AND there is no separate grounding conductor. This is not correct.

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  15. #15
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    The jacket of type AC cable is a listed EGC. No wire type EGC is required.

    250.118 Types of Equipment Grounding Conductors.
    (8) Armor of Type AC cable as provided in 320.108.
    320.108 Equipment Grounding Conductor. Type AC cable
    shall provide an adequate path for fault current as required
    by 250.4(A)(5) or (B)(4) to act as an equipment grounding
    conductor.



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    Default Re: sub panel

    I hope that is not a neutral on the ground block? (right of main)


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    Quote Originally Posted by Richard Skalski View Post
    I hope that is not a neutral on the ground block? (right of main)
    Why do you say that?


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    Quote Originally Posted by Richard Skalski View Post
    I hope that is not a neutral on the ground block? (right of main)
    The bond screw is installed. There would be no difference between the left and right bus function.

    All answers based on unamended National Electrical codes.

  19. #19
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    Quote Originally Posted by Robert Meier View Post
    The jacket of type AC cable is a listed EGC. No wire type EGC is required.
    Yea; the NEC has covered it's bases through this hop-scotch by ultimately saying the jacket must provide an adequate fault path or it cannot be used as an EGC. The same jacket when not factory bundled w/ conductors inside is limited to 6' for use as an EGC. The helical nature of it's construction creates so much resistance that they won't allow pieces longer than 6' w/o adding an EGC and also why there is specific limitation to 20 amps or less overcurrent protection. The OP is MC / made before AFC. What little AFC I encountered while still wearing the bags had a small bonding strap / conductor that looked like a piece of mini metal tape which served to shunt out those resistance creating spirals. I do not know, but assume that system is how the AFC jacket gets approval as a EGC. You look at the connectors, the enamel painted can, loose lock nuts and it is very unlikely there is any ground path there. Absent UL listing evidence that it is approved as an EGC I would call it for licensed review.


  20. #20
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    Quote Originally Posted by Garry Blankenship View Post
    Yea; the NEC has covered it's bases through this hop-scotch by ultimately saying the jacket must provide an adequate fault path or it cannot be used as an EGC. The same jacket when not factory bundled w/ conductors inside is limited to 6' for use as an EGC. The helical nature of it's construction creates so much resistance that they won't allow pieces longer than 6' w/o adding an EGC and also why there is specific limitation to 20 amps or less overcurrent protection. The OP is MC / made before AFC.
    What are you basing this comment on? MC cable of that age would have an insulated EGC within it's jacket. And what is AFC?


  21. #21
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    Quote Originally Posted by Robert Meier View Post
    What are you basing this comment on? MC cable of that age would have an insulated EGC within it's jacket. And what is AFC?
    Recollection. The first metal mfg. cable assembly I ever saw was called BX. No idea what those letters stand for, but always was 20 amps or less cable. Rarely ever encountered M/C cable which I understood to be steel flex conduit w/ the conductors built inside, but typically larger amperages. When aluminum became prevelant in it's various forms I was introduced to and installed branch circuiting with an aluminum jacketed amoured flexible cable, ( AFC ), but it may have stood for aluminum flex cable. Armoured Flex Cable, ( possibly aluminum flex cable ), and Metal Clad Cable are synomyms in my world. Both meaning a manufactured cable assembly with conductors and flexible metallic jacket. I simply never heard of AFC until aluminum was omnipresent which dated it's existence to me. MC was pre-aluminum and AFC was post in terms of time. Why do you believe older MC would have an insulated EGC ? Back then I believe they considered the jacket an adequate ground.


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    Quote Originally Posted by Robert Meier View Post
    What are you basing this comment on? MC cable of that age would have an insulated EGC within it's jacket. And what is AFC?
    I think the issue is with some of the older "BX" type cable that doesn't have the 16awg wire/strip bonded to the helical jacket. In the newer AC cables this conductor in combination with the metal jacket is suitable for EGC. In the older cables, with no wire/strip bonded to the jacket AND with no insulated EGC, the question is whether the jacket alone is suitable for use as an EGC or if we should consider this cable type to be type MC with no EGC present (and therefore unsuitable as a feeder in this application).


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    Some are confusing two similar but different metallic flexible cabling types. They have differences and cannot be called the same cable. Also sheath material does not determine the cable type.

    MC cable has an insulated ground and the sheath is not used as an EGC. Type MC cable does not have a bond strip. I have not seen MC with a steel sheath. There is now a type MC-ap with a grounding conductor that can be cut off flush with the connector and not connected to the box or device with a grounding screw.

    Type AC cable is different in that the sheath is the EGC as long as it has the internal bond strip. It also does not contain a grounding conductor. Type AC cable existed for many years prior to MC cable. It was available in both a steel and later an aluminum sheath.

    The original AC cable did not have a bond strip and cannot be used as an EGC.

    All answers based on unamended National Electrical codes.

  24. #24
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    Quote Originally Posted by Jim Port View Post
    Some are confusing two similar but different metallic flexible cabling types. They have differences and cannot be called the same cable. Also sheath material does not determine the cable type.

    MC cable has an insulated ground and the sheath is not used as an EGC. Type MC cable does not have a bond strip. I have not seen MC with a steel sheath. There is now a type MC-ap with a grounding conductor that can be cut off flush with the connector and not connected to the box or device with a grounding screw.

    Type AC cable is different in that the sheath is the EGC as long as it has the internal bond strip. It also does not contain a grounding conductor. Type AC cable existed for many years prior to MC cable. It was available in both a steel and later an aluminum sheath.

    The original AC cable did not have a bond strip and cannot be used as an EGC.
    I would note a few other things. The bonding strip was added to AC cable around 1958. I've never seen large AC like this (possible #4 or #2 AWG) that was installed prior to 1958. Also judging from the insulation (either TW, THW or THHN) I would say that this cable were manufactured after the inclusion of the boding strip. But, disclaimer here, I'm only guessing.

    Also I'm unsure if you can say that a cable manufactured without the bonding strip cannot be used as as EGC. Was the cable listed as such before a bonding strip was required?


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    Quote Originally Posted by Garry Blankenship View Post
    It's not legal to trim strands off a wire to make it fit.
    Say what? You do you get THAT from? Code reference please ... or any other reference you have for that matter.
    EDIT: ---> OOPS! I read that as saying that it is not ILlegal - my error - it is correct as stated.

    It was probably a legal grounding means when it was made, but not today.
    I doubt it was acceptable back when it was installed as shown, however, we do not know if the service equipment and the distribution panel are in the same structure or not - and it makes a difference for being acceptable or not when it was installed as shown.

    The acceptability of the bare neutral wire splice extention is questionable, but it is functional.
    An uninsulated neutral conductor which is feeding other-than-service-equipment is functional in your book?

    It is not allowed in THE book which matters (the NEC).

    A ground for that feeder is the only thing worth calling IMO.
    That missing ground for that feeder is only the starting point, and more information is needed for that missing ground ... such as is the distribution panel it feeds in the same structure or a different structure and when it was installed - regardless, though, that installation has now been recognized as being less than safe, thus it should be called out as a safety item regardless of when it was installed.

    Last edited by Jerry Peck; 06-03-2012 at 08:34 PM. Reason: It is NOT LEGAL to cut the strands off, it IS ILLEGAL to cut the strands off ... I goofed when I read that. Me bad. :o
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    Default Re: sub panel

    The sub panel is in the same structure.


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    Quote Originally Posted by Russell Melville View Post
    The sub panel is in the same structure.
    With the distribution panel in the same structure the neutral is required to be insulated and a separate neutral and separate grounding conductor are required, even back to when that possibly could have been installed.

    About the only thing which could have made that acceptable at one time is that the distribution panel was 'the service equipment' at one time and that the 'feeders' were actually the 'service entrance conductors', but that brings up another problems about the service entrance conductors entering the structure and no service disconnect being close - unless the distribution panel (which would have been the service equipment back then) is on the other side of that wall, and I doubt the distribution panel is that close to what is shown in the photo.

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  28. #28
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    Why is there a missing EGC in the subpanel feeder, isn't the wiring method AC cable?


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    Quote Originally Posted by Robert Meier View Post
    Why is there a missing EGC in the subpanel feeder, isn't the wiring method AC cable?
    We don't know if the EGC is missing or not - it all hinges on whether there is a low-impedence bonding strip inside the metal jacket.


  30. #30
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    Quote Originally Posted by Corn Walker View Post
    We don't know if the EGC is missing or not - it all hinges on whether there is a low-impedence bonding strip inside the metal jacket.
    I would assume that the strip is present given some of the facts that I mentioned earlier but this thread presents another question, where is it written that Type AC without the bonding strip was never permitted to be used as an EGC?


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    Default Re: sub panel

    It probably reverts back to a listing and labeling issue regarding the grounding of AC cables.

    Jerry, how would you know the resultant ampacity of the remaining strands?

    All answers based on unamended National Electrical codes.

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    Quote Originally Posted by Jim Port View Post
    Jerry, how would you know the resultant ampacity of the remaining strands?
    Jim,

    I went back and re-read what you were questioning ... I made a big OOPS! as I read it as 'It's not ILlegal to trim strands off a wire to make it fit.' instead of as "It's not legal to trim strands off a wire to make it fit."

    It is NOT LEGAL to cut the strands off, it IS ILLEGAL to cut the strands off ... I goofed when I read that. Me bad. I am going back and changing my post with an edit note - THANK YOU for pointing that out.

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  33. #33
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    Quote Originally Posted by Jerry Peck View Post
    Say what? You do you get THAT from? Code reference please ... or any other reference you have for that matter.
    EDIT: ---> OOPS! I read that as saying that it is not ILlegal - my error - it is correct as stated.



    I doubt it was acceptable back when it was installed as shown, however, we do not know if the service equipment and the distribution panel are in the same structure or not - and it makes a difference for being acceptable or not when it was installed as shown.

    An uninsulated neutral conductor which is feeding other-than-service-equipment is functional in your book?

    It is not allowed in THE book which matters (the NEC).

    That missing ground for that feeder is only the starting point, and more information is needed for that missing ground ... such as is the distribution panel it feeds in the same structure or a different structure and when it was installed - regardless, though, that installation has now been recognized as being less than safe, thus it should be called out as a safety item regardless of when it was installed.
    to 12"

    Geeze J.P., you can confuse things. It was stated earlier that it is illegal to cut off strands and that the grounding issues should be called. That neutral wire is insulated. The short uninsulated piece of neutral is, as stated, functional, it is no thing in the grand scheme and yes ~ technically not code compliant. Look at it as a wire that was stripped of it's insulation a bit more than needed. If it was a hot, it would be very serious and an entirely different safety concern. Bare ground wires are allowed around the entire panel space and they terminate, ( in this case ), in the same place as that bare neutral wire. Ditto the neutral wire of the service entrance cable - - - it is bare / uninsulated inside the panel. A fair amount of the posts here are electricians and none of them seem too concerned about it. They know it's not legal and they also know it's like doing 26 in a 25.


  34. #34
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    Quote Originally Posted by Jerry Peck View Post
    Comment that nothing was wrong as you described it?

    The only comment I might make from your description is that if they changed the 60 amp breaker out to a 100 amp breaker they would have a 100 amp distribution panel there ... keeping in mind (of course) that the service equipment panel also had a 100 amp main breakers and that if 100 amps was used at the distribution panel the main breaker would likely trip too - or may trip first - and that would not be a good thing.

    In other words, replacing that 60 amp breaker with a 100 amp breaker could lead to an unexpected "lights out" situation.
    Jerry what happened to the sub panel education?


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    Default Re: sub panel

    My first thought is this situation should be reviewed by a qualified electrical contractor. Also, feeding a 100 A breaker from a 100 A breaker is not a good practice since you won't be sure which will blow first.


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    Quote Originally Posted by Don McCubbin View Post
    My first thought is this situation should be reviewed by a qualified electrical contractor. Also, feeding a 100 A breaker from a 100 A breaker is not a good practice since you won't be sure which will blow first.
    Except for possibly of needing to check two places to reset the breaker there is no issue. The issue would be why the breaker tripped.

    All answers based on unamended National Electrical codes.

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    Quote Originally Posted by Paul Johnston View Post
    Jerry what happened to the sub panel education?
    We were in his submarine, so no problem.

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    Quote Originally Posted by Garry Blankenship View Post
    to 12"
    Huh? What is that in reference to???

    Geeze J.P., you can confuse things. It was stated earlier that it is illegal to cut off strands ...
    No, it was stated that it was no legal to cut the strands off ... I read it as it was not illegal to cut the strands off ... I see I am not the only one reading "illegal" instead of "legal". You stated it correctly: it is not legal to cut the strands off.

    [quoto]That neutral wire is insulated.[/quote]

    No it isn't. MOST of the neutral wire is insulated ... but SOME of the neutral wire is not insulated. You say so yourself right here:
    The short uninsulated piece of neutral is, ...
    as stated, functional, ...
    No it isn't. The ENTIRE neutral is required to be insulated if the neutral is not the service entrance conductor neutral - and that uninsulated section of the neutral *is not* part of the service entrance conductors.

    Look at it as a wire that was stripped of it's insulation a bit more than needed.
    Do you need glasses? First, that is not the same wire, second, if it was the same wire and you stripped that much too much you would be replacing it with a properly insulated and stripped conductor.

    Bare ground wires are allowed around the entire panel space and they terminate,
    Yeah, but we are not talking about a ground wire, we are talking about a neutral. TWO DIFFERENT THINGS.

    I'm game, let's ask them:
    Quote Originally Posted by Garry Blankenship View Post
    A fair amount of the posts here are electricians and none of them seem too concerned about it. They know it's not legal and they also know it's like doing 26 in a 25.
    a) How many of the electrician here go with Garry and say that uninsulated neutral is NOT a problem?
    b) How many think it needs to be addressed?

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  39. #39
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    Quote Originally Posted by Jerry Peck View Post
    I'm game, let's ask them:


    a) How many of the electrician here go with Garry and say that uninsulated neutral is NOT a problem?
    b) How many think it needs to be addressed?
    I put in my 2 cents in post #12.


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    Default Re: sub panel

    Seeing there are only three wires, isn't it obvious that the white wire is being used as a ground and not a neutral? If that is the case, does it matter if the ground conductor is bare or insulated? I am the least of experts here so I ask humbly.


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    Quote Originally Posted by Russell Melville View Post
    Seeing there are only three wires, isn't it obvious that the white wire is being used as a ground and not a neutral?
    Without additional information as to if there is a bonding strip inside what appears to be old AC cable ... some here are going the route of assuming that there is a bonding strip and thus the other metal covering is the ground path ... while others here, myself included, are not inclined to presume that there is is bonding strip inside it and therefore the outer metal covering may not be serving as the ground path, as such the white insulated conductor is serving as the neutral *and* the ground, and that is only allowed for service conductors, not for feeder conductors.

    If that is the case, does it matter if the ground conductor is bare or insulated?
    A ground conductor is allowed to be bare or insulated, however, we suspect that is serving as a neutral and therefore it must be insulated.

    Provided, of course, that we are both referring to the same conductor.

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    Default Re: sub panel

    Thanks JP, I am learning and admit to my shame that I didn't take a picture of the sub panel. I don't remember the age of the house, but it is approx 60 years old. The sub panel was fairly new, probably updated the same time as the main panel. The BX cable that is feeding it appears to be quite old. I would guess someone had a piece of the BX cable laying around and used it. I am with you and doubt there is a bonding strip inside, simply because of the age of the cable.


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    I can see how it could be said that functionally the splice is an extreme case of too much insulation being stripped off before being terminated in the bus, if you disregard the splice. To a much lesser extent I can almost see someone saying it is not a hazard, that is until you try to take the cover off and you have a current carrying conductor that is bare for a foot or more easily exposing you to a shock hazard.

    As an installer would I accept this? No way.

    As a customer would I accept this? H ell no.

    As an inspector would I accept this? No ****@#! way. Oh yeah, and your jobs will be getting a much harder look too.

    All answers based on unamended National Electrical codes.

  44. #44
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    Default Re: sub panel

    OK. The uninsulated neutral splice extention, ( inside the panel ), is not code compliant. Assuming an inspector knows that, he/she is obligated to report it. I could be wrong. but believe all posters agree with that, including yours truly. That said;, ( hypothetical situation ), the new home owner removes the panel cover and wraps his/her hand right around that bare neutral extention. How bad is that person going to be shocked ? There are lots of unlikely circumstances that could be therorized based upon where this hypothetical person's other appendages are, but for this question please assume both feet on the ground and the second hand is at their side. Is this the end of this new home owner ?


  45. #45
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    Default Re: sub panel

    Quote Originally Posted by Garry Blankenship View Post
    OK. The uninsulated neutral splice extention, ( inside the panel ), is not code compliant. Assuming an inspector knows that, he/she is obligated to report it. I could be wrong. but believe all posters agree with that, including yours truly. That said;, ( hypothetical situation ), the new home owner removes the panel cover and wraps his/her hand right around that bare neutral extention. How bad is that person going to be shocked ? There are lots of unlikely circumstances that could be therorized based upon where this hypothetical person's other appendages are, but for this question please assume both feet on the ground and the second hand is at their side. Is this the end of this new home owner ?
    Under normal conditions nothing will happen.


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    Default Re: sub panel

    Quote Originally Posted by Robert Meier View Post
    Under normal conditions nothing will happen.
    Thank you Robert. That is my point. Illegal ~ yes; a serious hazzard ~ no. Panels are full of bare grounded wires, like that bare service entrance neutral which oddly is not required to be insulated, ( evidently ). Wired correctly they are all bonded together, eliminating any differences in potential. Even the can itself has the same shock potential as the ground wires or that neutral wire. It's terrible looking work and I would have to clean it up for that reason before I would change it for safety reasons. Assuming that splice is done correctly and neatly, I'm not seeing any gain made in customer safety. I know we can't pick & choose what we want to report, but it is not a skull & crossbones situation. Maybe a trip hazzard. Statements like " An uninsulated neutral conductor which is feeding other-than-service-equipment is functional in your book?" and "To a much lesser extent I can almost see someone saying it is not a hazard, that is until you try to take the cover off and you have a current carrying conductor that is bare for a foot or more easily exposing you to a shock hazard." are missleading. An inspector with limited electrical depth could only become more confused. That neutral is functional and it is no more a shock hazzard than any of the other bare grounded wires inside that panel or the panel can itself for that matter.


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    Default Re: sub panel

    Quote Originally Posted by Russell Melville View Post
    Seeing there are only three wires, isn't it obvious that the white wire is being used as a ground and not a neutral? If that is the case, does it matter if the ground conductor is bare or insulated? I am the least of experts here so I ask humbly.
    Yes that is quite likely, and if found to be the case the conductors should be marked or tagged.

    I wouldn't be surprised if the "sub" is set up as straight 240V only thing being supplied off the "sub" (since its in the same structure) is just 240V straight loads or those excepted in past, for example: an older electric cook top & wall oven, and/or an older electric dryer, none of which require a "neutral" existing.

    Its an older install, obviously; and we've been provided with no information on the "sub" except for a 100A breaker on same, and IIRC, a 60A (did I read that somewhere?) load. As to the "why" might very well be those circuits off the "sub" were wired with SE...and the conductors and terminations of the feeder and "sub" and beyond are being limited to a lower ampacity/temperature rating

    Last edited by H.G. Watson, Sr.; 06-06-2012 at 12:08 PM.

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    Default Re: sub panel

    Quote Originally Posted by H.G. Watson, Sr. View Post
    Yes that is quite likely, and if found to be the case the conductors should be marked or tagged.

    I wouldn't be surprised if the "sub" is set up as straight 240V only thing being supplied off the "sub" (since its in the same structure) is just 240V straight loads or those excepted in past, for example: an older electric cook top & wall oven, and/or an older electric dryer, none of which require a "neutral" existing.

    Its an older install, obviously; and we've been provided with no information on the "sub" except for a 100A breaker on same, and IIRC, a 60A (did I read that somewhere?) load. As to the "why" might very well be those circuits off the "sub" were wired with SE...and the conductors and terminations of the feeder and "sub" and beyond are being limited to a lower ampacity/temperature rating
    Thanks for that Russ & Dub Ya. I never considered a 240 volt only sub-panel. So if it is a 240 volt only sub-panel, you call it a ground wire and it's legal / all good, ( albeit unsightly ). If you call it a neutral, it's "not functional" and it's a "current carrying shock hazzard". Please keep in mind that the conductor is not touched - - - yet what we call it makes it either fine or according to some not functional and a shock hazzard. A soft apology to both J.P.s, but both too bright to avoid the temptation of stirring the pot a bit. The difference is Jim knows where Jerry knows what "The Book" says, ( a very valuable contributor I might add ).


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    Default Re: sub panel

    Would someone actually run a straight 1, 240 volt feeder to a subpanel in a house with 3 wire AC cable?


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    Default Re: sub panel

    Quote Originally Posted by Robert Meier View Post
    Would someone actually run a straight 1, 240 volt feeder to a subpanel in a house with 3 wire AC cable?
    For whatever reasons, I'm under the impression the panel pictured is not the original service panel and/or not the original (exact) service panel location - and that the "sub" panel is nearby and between the old service panel location and the loads it's supplying via a feeder (i.e. installed replacement panel closer to SE and landed older 2-wire+grnd 240 circuits on sub rather than extend back to new service panel location or re-wire them).


    Sure, why NOT ?? Its over 20A, its using the indicated conductor for ground, and its not of a restricted size, and wasn't limited as to length since hmmm at least a few code cycles prior to 99, its been limited to 60C ampacity and has 60C terminations on the 60A breaker, Its in an attached garage (next to OH door) isn't it? The indicated conductor is full size, being used for ground, Have on the truck or at the supply for whip use, go ahead use it, esp. if was a paid panel replcement, emergency or unplanned work why the heck not?


    The flexible cable looks coated/jacketed to me.

    Last edited by H.G. Watson, Sr.; 06-06-2012 at 03:49 PM.

  51. #51
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    Default Re: sub panel

    Quote Originally Posted by H.G. Watson, Sr. View Post
    Sure, why NOT ?? Its over 20A, its using the indicated conductor for ground, and its not of a restricted size, and wasn't limited as to length since hmmm at least a few code cycles prior to 99, its been limited to 60C ampacity and has 60C terminations on the 60A breaker, Its in an attached garage (next to OH door) isn't it? The indicated conductor is full size, being used for ground, Have on the truck or at the supply for whip use, go ahead use it, esp. if was emergency or unplanned work why the heck not?


    The flexible feeder cable looks coated/jacketed to me.
    It's undoubtedly type AC cable, you can see the old paper wrap around the individual conductors in the photo. I'm still not sold on the possibility that this feeds a 240 volt panel without a neutral.


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    Default Re: sub panel

    Quote Originally Posted by Robert Meier View Post
    It's undoubtedly type AC cable, you can see the old paper wrap around the individual conductors in the photo. I'm still not sold on the possibility that this feeds a 240 volt panel without a neutral.
    Unless I missed something in the thread...I don't believe the OP has indicated either way.

    Imagine, if you would - a FPE split bus panel or Zinsco/Sylvnia/ panel replacement - on the cheap and fast - after a HI report, negotiated repair demanded completed and re-inspected before closing, or a quick replacement post closing, post-binder issuance, and pre-policy issueance, the new HO getting a letter from the home insurer declining coverage unless panel is replaced. Just few examples of paid work (T&M) on budget and time-is-of-the-essence minimal fix.


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    Default Re: sub panel

    Quote Originally Posted by Robert Meier View Post
    Under normal conditions nothing will happen.
    Under normal conditions ... fires don't start either.

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    Default Re: sub panel

    The sub panel was approx 30 feet away, and I do remember it being used for a hot water heater and dryer. Both panels looked relatively new, which makes me wonder why they didn't increase the entance cable size and install a 200 apm panel. The entance cable looked quite new and I'm sure was updated the same time as both panels.


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    Default Re: sub panel

    I think your right H.G. It was a low budget house, an elderly women lived there and the family was very anxious to unload it. I was an insurance inspector for Mueller for years and found a lot of old and obsolete panels that would be required to be replaced.


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    Default Re: sub panel

    Quote Originally Posted by Russell Melville View Post
    The sub panel was approx 30 feet away, and I do remember it being used for a hot water heater and dryer. Both panels looked relatively new, which makes me wonder why they didn't increase the entance cable size and install a 200 apm panel. The entance cable looked quite new and I'm sure was updated the same time as both panels.
    Quote Originally Posted by Russell Melville
    I think your right H.G. It was a low budget house, an elderly women lived there and the family was very anxious to unload it. I was an insurance inspector for Mueller for years and found a lot of old and obsolete panels that would be required to be replaced
    Thanks for the confirmation Russell, that the "sub" panel is just 240V. Perhaps now all the chicken little "hazard of a bare neutral" when its groundING conductor baloney can finally stop. The presently white (identified as a grounded conductor) but actually a grounding conductor should be permanently marked green or tagged in both panels.

    They wouldn't need to increase the service capacity if load calculations don't require it. 200A SE cable and main breaker panel if unnecessary, is significantly more expensive than 100A equipment.


  57. #57
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    Default Re: sub panel

    Quote Originally Posted by H.G. Watson, Sr. View Post
    Thanks for the confirmation Russell, that the "sub" panel is just 240V. Perhaps now all the chicken little "hazard of a bare neutral" when its groundING conductor baloney can finally stop. The presently white (identified as a grounded conductor) but actually a grounding conductor should be permanently marked green or tagged in both panels.

    They wouldn't need to increase the service capacity if load calculations don't require it. 200A SE cable and main breaker panel if unnecessary, is significantly more expensive than 100A equipment.
    I would feel most vindicated, if this were true. However, dryer motors are typically 120 volt. That means the much discussed wire is being used as a neutral, regardless of what we call it.


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    Default Re: sub panel

    universal motors, hush. you're confusing timer circuits. Anyway older have tsf on board.Finally, doesn't mean hill of beans - a 2-wire plus ground is allowed for a dryer outlet, N&G are bonded on the terminal block. Still allowed.


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    Default Re: sub panel

    Quote Originally Posted by H.G. Watson, Sr. View Post
    a 2-wire plus ground is allowed for a dryer outlet, N&G are bonded on the terminal block. Still allowed.
    Still allowed to remain in use where they exist in existing installations, not still allowed to be installed for new installations.

    And even the existing installations have conditions and requirements which may not have been met at the time of installation and/or which may no longer be met by changes over time.

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    Default Re: sub panel

    Forgive me if I repeat something already stated, this thread is soooo long but have read threw half of it.

    Biggest issue for me would be the insulated bonding screw.
    Bend radius in the mickey mouse ears, questionable.
    Cables subject to damage, side and bottom.
    I would perfer trimmed strands for voltage drop issues when necessary and as the AHJ I would not consider it illegal if the conductor is oversized, (not applicable in this case however).
    Whether BX or flexible metal conduit (FMC), if considered a grounding means at the year it was installed, then it is legal, correct, and accepted as such.
    I doubt the stab rating in that 100 amp panel is in excess of 60 amps.


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