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Thread: Odd intriguing and perhaps dangerous multi unit grounding question/problem: JUMPER??

  1. #51
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    There has been no new panel installed and feeder installed in my working on this proj

    ~
    Last edited by docj67; 01-08-18 at 02:27 PM. Reason: typo

  2. #52
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    Quote Originally Posted by al hildenbrand View Post
    OK. I hear (read, really) that. But again, the current in the Service Entrance Mast Conductors is caused by ( and only by ) the connected LOAD.

    There's a reason the additional panel and feeder were installed. . . I can't see it from this side of my screen. Why was additional branch circuit OCPD space required? Is it because the new branch circuits go to new loads?
    Al, you have great points, but he cannot possibly answer those questions and it falls outside his scope of work. The guy is not getting paid to fix the whole shebang.
    "Electricity is really just organized lightning." George Carlin


    Derek

  3. #53
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    Quote Originally Posted by al hildenbrand View Post

    There's a reason the additional panel and feeder were installed. . . I can't see it from this side of my screen. Why was additional branch circuit OCPD space required? Is it because the new branch circuits go to new loads?
    How do we know there was not two panels to begin with?
    "Electricity is really just organized lightning." George Carlin


    Derek

  4. #54
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    Quote Originally Posted by docj67 View Post
    A has two #8's
    B has nothing ( no EGC visible ) (FPE PANEL)
    The conduit is the EGC.

    If panel B is the one you are replacing and there are no mysterious bare #8 wires, it can be replaced.

    Panel A may or may not have a problem. Hardest part is not knowing where the other ends are.

    Two wires are puzzling. If they simply were unneeded GECs that went to part of the building GES, they would be harmless. Assuming they land in the EGC bus and not the neutral bus.

    A connection at the service equipment to a GES still has to be done. Fixing your customers stuff without fixing the others there is problematic.

    You said you were going to sub this part out?
    "Electricity is really just organized lightning." George Carlin


    Derek

  5. #55
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    yes most likely

    sub to one of
    my mentors
    or
    my hopeful new journeyman's current boss

    15 and 30 years experience respectively

    can one conduit be an egc for two feeders?

    and yes my intention and conmunication to client

    from start hass included entire building: all units inclusive -thx.
    appreciate reminders to make sure Service equipment is included, thats partially why i want a veteran to handle it under my management.

    I request closure of thread and further dialogue to occur off line .....thx for continued moderatinf


    Quote Originally Posted by jumper View Post
    The conduit is the EGC.

    If panel B is the one you are replacing and there are no mysterious bare #8 wires, it can be replaced.

    Panel A may or may not have a problem. Hardest part is not knowing where the other ends are.

    Two wires are puzzling. If they simply were unneeded GECs that went to part of the building GES, they would be harmless. Assuming they land in the EGC bus and not the neutral bus.

    A connection at the service equipment to a GES still has to be done. Fixing your customers stuff without fixing the others there is problematic.

    You said you were going to sub this part out?

  6. #56
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    Quote Originally Posted by docj67 View Post
    There has been no new panel installed and feeder installed in my working on this proj
    Ahh, I apologize. By typing "new panel", and 'new loads", I am only referring to the Sq D HOM subpanel and the load connected to the branch circuits that come from it. That Sq D HOM subpanel is "new" to the as-built decades-old FPE assembly.

    I never meant to say the "new" is the project you are doing right now, nor that you are causing a problem. As you say, Doc, in the opening post ( OP ) title: "perhaps dangerous". The four-service multi-condo existing Premises Wiring (System), as first seen by you before you did anything, seems to be in a heavily loaded state with respect to the Service Entrance Mast Conductors. Whether the Service Entrance Mast Conductors are overloaded, in fact, requires more information than we've yet seen in this thread.

    I am used to seeing this kind of old service in the multidwelling fourplexes that are common in the inner City of my work area. The FPE equipment dates the service/subpanel assembly in your posts as several decades old or older.

    The original FPE service/subpanel assembly connected load will tend to creep larger over time as dishwashers, microwaves, hot tubs, whatever, are added. I'm not trying to say that has, in fact, happened, BUT that addition of the Sq D HOM subpanel was for more branch circuit overcurrent protective devices. . . no?
    Another Al in Minnesota

  7. #57
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    Quote Originally Posted by jumper View Post
    How do we know there was not two panels to begin with?
    Yes, perhaps an old FPE subpanel was replaced with a Sq D HOM panel. . . one can hope this is the case and that no appreciable new load has been added since the original Service Conductor sizing calculation occurred 3 to 5 decades ago.

    I may be over cautious. . .

    My field experience with the fourplexes in my area have taught be to be cautious.
    Another Al in Minnesota

  8. #58
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    cautious and conservative is how i run my business:egc question reasked

    and just a last
    comment for Derek; new subpanel will have new feeders w egc as old one is impractical to chase

    Im on vacation to Oregon!!! Yahoo!!

    thx all!! was fun!!!!


    (still curious if one conduit can be used as egc for two sets of feeders)

    best regards,js




    Quote Originally Posted by al hildenbrand View Post
    Yes, perhaps an old FPE subpanel was replaced with a Sq D HOM panel. . . one can hope this is the case and that no appreciable new load has been added since the original Service Conductor sizing calculation occurred 3 to 5 decades ago.

    I may be over cautious. . .

    My field experience with the fourplexes in my area have taught be to be cautious.

  9. #59
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    Quote Originally Posted by docj67 View Post
    (still curious if one conduit can be used as egc for two sets of feeders)
    When all the conductors of two sets of feeders are contained within a metallic raceway, a raceway identified in 250.118 as a suitable EGC (Equipment Grounding Conductor), the single raceway is acceptable as the EGC for both feeders.

    Have a great vacation.

    If you wish, at some point in the future, it would be fun to hear the outcome of the project described in this thread.
    Another Al in Minnesota

  10. #60
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    grateful to both of you

    Quote Originally Posted by al hildenbrand View Post
    When all the conductors of two sets of feeders are contained within a metallic raceway, a raceway identified in 250.118 as a suitable EGC (Equipment Grounding Conductor), the single raceway is acceptable as the EGC for both feeders.

    Have a great vacation.

    If you wish, at some point in the future, it would be fun to hear the outcome of the project described in this thread.

    Will do!!! For sure!!! Thx for Egc info

    Newbie Nate is sharp but needs some down time to recharge his batteries bc that
    4plex has kicked my u know what
    plus i need more time to dry behind the ears!

    In gratitude,js

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