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Thread: Bonding screw

  1. #1
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    Default Bonding screw

    Hi, Glad to be here.
    I'm not an inspector, or electrician. Just a home owner who
    saw something in my home wiring, and after reading one of the threads here
    am wondering if this is correct. My well stopped pumping for a short time which caused me to open
    the box and look. Saw no problem so I started searching the web for answers.
    Finally found a plumbing problem and fixed it. Well works again no problem.


    But inside this box.....I would suppose it's a sub panel, the green bonding screw is in place. I read here and other places that the green bonding screw should not
    be there.


    Since I have an additional sub panel that hooks up to an unattached building I opened that box to compare, and No bonding screw.


    So which one of these setups is correct......or are they both correct just different.


    NOTE that neither has ever been a problem, I just found this and after reading
    am wanting to know if this is a problem and potential danger?

    SubPaneltoWell.jpg


    1 Main panel supply's a sub panel


    2 80 amp fuse at main panel to sub panel


    3 Three wire connection to sub panel


    4 Sub panel has green bonding screw installed.


    5 Sub panel supplies air conditioner - heat pump with 80 amp fuse


    6 Also supplies well with 30 amp fuse


    Should the above sub panel have green bonding screw installed.........?

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  2. #2
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    Default Re: Bonding screw

    Quote Originally Posted by Don McMan View Post
    Since I have an additional sub panel that hooks up to an unattached building ...
    The first question before an answer is:

    You have a remote panel (not the service equipment panel) "that hooks up to an unattached building" - do you mean: a) that feeds a unattached (detached) building; or b) that is located on a detached building?

    And, if you mean b) that the remote panel is located on/in a detached building, do you know about when was that done; i.e., that it may have been original to the house and the house was built in xxxx; the pump house was added later; etc - if you know?

    Jerry Peck
    Construction Litigation Consultant ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

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    Default Re: Bonding screw

    Quote Originally Posted by Don McMan View Post
    Hi, Glad to be here.
    I'm not an inspector, or electrician. Just a home owner who
    saw something in my home wiring, and after reading one of the threads here
    am wondering if this is correct. My well stopped pumping for a short time which caused me to open
    the box and look. Saw no problem so I started searching the web for answers.
    Finally found a plumbing problem and fixed it. Well works again no problem.
    But inside this box.....I would suppose it's a sub panel, the green bonding screw is in place. I read here and other places that the green bonding screw should not
    be there.
    Since I have an additional sub panel that hooks up to an unattached building I opened that box to compare, and No bonding screw.
    So which one of these setups is correct......or are they both correct just different.
    NOTE that neither has ever been a problem, I just found this and after reading
    am wanting to know if this is a problem and potential danger?
    1 Main panel supply's a sub panel
    2 80 amp fuse at main panel to sub panel
    3 Three wire connection to sub panel
    4 Sub panel has green bonding screw installed.
    5 Sub panel supplies air conditioner - heat pump with 80 amp fuse
    6 Also supplies well with 30 amp fuse
    Should the above sub panel have green bonding screw installed.........?
    Don,

    I think I can guess where Jerry is going with this.

    At one point in the fairly recent past (I think prior to the 2008 NEC, but I would have to double-check), it was acceptable, under very specific conditions, to not have to separate neutral and equipment grounding at detached buildings/locations. As a result, some panels at locations separate from the building that holds the service equipment (for example, a pump house) might not have isolated neutral and equipment grounding conductors.

    This would depend on a few items, including the age of the "sub-panel" installation and whether or not there was a direct metal connection back to the building that holds the service equipment.

    So, is there a grounding electrode (ground rod) near the well?
    When was the well electrical installed?
    When was the detached building constructed (specifically, when was the electrical installed)?

    I suspect Jerry will do a better job of explaining it than I will.

    "Bring out yer dead"
    "I'm not dead yet!"
    http://www.FullCircleInspect.com/

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    Default Re: Bonding screw

    OK, and Thanks for the reply.
    Although I don't know specific dates.


    The panel that powers the well, is attached to the house, then a wire goes from there
    to the well house and directly attaches to the well pump 500ft below the ground .
    There is also a metal pipe that goes from the well house back to the house.

    SubPaneltoWell.jpg



    Also the current house was built in 2004, but the well house was there since the 1970's and powered a house that burned down in 1998.....from and electrical problem,
    or so the story goes. I bought the house about 4 years ago.


    The other 2 wires to the air conditioner which is right next to the house.
    __________________________________________________ __________________________________
    On the other side of the house there is a box attached to the house,
    that feeds an unattached (detached) building.
    It has buried wire that goes to a cottage type building, and inside to another panel. That panel,
    has 3 20amp fuses, a 15 amp fuse, and a double 20 amp fuse which powers the stove.

    panaeltoCottage.jpg



    The wire that powers this has wire and on the wire there is a date of 2004.
    I believe that's when the wire was made because it is printed on the black wire in yellow.


  5. #5
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    Default Re: Bonding screw

    Quote Originally Posted by [COLOR=#333333
    Don,[/COLOR]

    I think I can guess where Jerry is going with this.

    At one point in the fairly recent past (I think prior to the 2008 NEC, but I would have to double-check), it was acceptable, under very specific conditions, to not have to separate neutral and equipment grounding at detached buildings/locations. As a result, some panels at locations separate from the building that holds the service equipment (for example, a pump house) might not have isolated neutral and equipment grounding conductors.

    This would depend on a few items, including the age of the "sub-panel" installation and whether or not there was a direct metal connection back to the building that holds the service equipment.

    So, is there a grounding electrode (ground rod) near the well?
    When was the well electrical installed?
    When was the detached building constructed (specifically, when was the electrical installed)?

    I suspect Jerry will do a better job of explaining it than I will.
    So, it probably is OK, which brings up the question, what changed prior to 2008 that
    made it OK.

    Seems that since there has been no problems all is good, but what happens when I sell
    this place, and the new guy builds a garage or something next to the well house, then runs a panel off the first panel pictured above. Would it be just like the well house is the main panel since the green screw is in.

    I should most probably not worry about any of it, but as stated the house that was here before burned down due to electric, and while gardening, I have dug up artifacts.....LOL.
    Just enough to make me skiddish so better to be informed than not.

    Anyway, Thanks to you guys who have replied. I see from reading some of the threads here it's a complicated business, and I appreciate your prompt replies.

    - - - Updated - - -

    Quote Originally Posted by [COLOR=#333333
    Don,[/COLOR]

    I think I can guess where Jerry is going with this.

    At one point in the fairly recent past (I think prior to the 2008 NEC, but I would have to double-check), it was acceptable, under very specific conditions, to not have to separate neutral and equipment grounding at detached buildings/locations. As a result, some panels at locations separate from the building that holds the service equipment (for example, a pump house) might not have isolated neutral and equipment grounding conductors.

    This would depend on a few items, including the age of the "sub-panel" installation and whether or not there was a direct metal connection back to the building that holds the service equipment.

    So, is there a grounding electrode (ground rod) near the well?
    When was the well electrical installed?
    When was the detached building constructed (specifically, when was the electrical installed)?

    I suspect Jerry will do a better job of explaining it than I will.
    So, it probably is OK, which brings up the question, what changed prior to 2008 that
    made it OK.

    Seems that since there has been no problems all is good, but what happens when I sell
    this place, and the new guy builds a garage or something next to the well house, then runs a panel off the first panel pictured above. Would it be just like the well house is the main panel since the green screw is in.

    I should most probably not worry about any of it, but as stated the house that was here before burned down due to electric, and while gardening, I have dug up artifacts.....LOL.
    Just enough to make me skiddish so better to be informed than not.

    Anyway, Thanks to you guys who have replied. I see from reading some of the threads here it's a complicated business, and I appreciate your prompt replies.


  6. #6
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    Default Re: Bonding screw

    It would be very helpful if you would post more photographs were you widen the view to the conduits and cables which enter each of those panels. I saw some concerning things in the Panel which supplies the Cottage. A wider photograph would help us to see if the 2 conductors from that double pole breaker actually go into separate conduits and perhaps make a guess as to why that might be.

    I have some additional questions:

    Is there only one utility meter on the property?

    Were is the Service Disconnecting Means; which means the very first place were you could cut off all power to the entire premises? To answer this question begin with the side of the house that faces the road, which is side 1, and count clockwise so that the side to the left as seen from the road is side 2 and so forth. Then say which side each of those panels is on and do not leave out the Service Panel that contains the Service Disconnecting Means.

    Is there a single wire in the Cottage which goes from the cottage's panel to a ground rod or into the ground just outside the building? A photograph with the cottage panel's cover removed would be most helpful.

    What year was the cottage built?

    Is the well casing metal?

    Is there a disconnect for the pump, such as an enclosed switch, in the pump house?
    ENCLOSED-SWITCH-SQUARE-D.JPG

    Does the pump house have any luminaire/s (lighting fixtures) no matter how simple; such as a porcelain socket with a pull string switch; or receptacle/s?

    --
    Tom Horne


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    Default Re: Bonding screw

    That panel is a 240 volt only panel. There is no neutral.

    All answers based on unamended National Electrical codes.

  8. #8
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    Default Re: Bonding screw

    Quote Originally Posted by Jim Port View Post
    That panel is a 240 volt only panel. There is no neutral.
    Which of the panels are you referring to? I would guess that you mean the one for the Air Conditioner and the Well Pump but I want to be sure.

    I know that I regularly forget to do it so don't think this is meant to be some sort of attack on you. I have been admonished for not quoting the posting that I'm responding to with the quote reduced to the portion of a multi part post that I'm trying to address. I'm now convinced that doing that is very helpful in following a thread.

    --
    Tom Horne

    Last edited by THOMAS HORNE; 09-12-2019 at 10:38 AM.

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    Default Re: Bonding screw

    " what changed prior to 2008 that
    made it OK."

    2 possibilities occur to me:

    1. constant trend since 1897 code, people less tolerant of risk, and code constantly becoming more restrictive

    2. someone figured out that they could sell more wire



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    Default Re: Bonding screw

    (I accidentally deleted my answer while trying to change one word.)
    To answer the Green Screw part of the question, it looks like the green screw came out of someone's pocket. It's not wired, so it really doesn't matter.
    The other thing I think I'm seeing is that the outgoing ground wire is hooked up to the incoming terminal on the panel, and the incoming ground is hooked up under a small screw.
    I'm not even sure how it fits there. I think there are terminal adapters available for doing this.


  11. #11
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    Default Re: Bonding screw

    Quote Originally Posted by THOMAS HORNE View Post
    I have been admonished for not quoting the posting that I'm responding to with the quote reduced to the portion of a multi part post that I'm trying to address. I'm now convinced that doing that is very helpful in following a thread.
    Tom,

    I don't recall that you were admonished for using full quoted posts, just explained the advantages of shortening quotes to the part being referred to.

    Jerry Peck
    Construction Litigation Consultant ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  12. #12
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    Default Re: Bonding screw

    Quote Originally Posted by Jerry Peck View Post
    Tom,

    I don't recall that you were admonished for using full quoted posts, just explained the advantages of shortening quotes to the part being referred to.
    Lets not quibble over a single word. It's not a productive way to use our time.

    --
    Tom Horne


  13. #13
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    Default Re: Bonding screw

    Quote Originally Posted by THOMAS HORNE View Post
    Lets not quibble over a single word. It's not a productive way to use our time.
    Curious if you saw the ? I suspect you may have missed it?

    Jerry Peck
    Construction Litigation Consultant ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

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    Default Re: Bonding screw

    Quote Originally Posted by THOMAS HORNE View Post
    Which of the panels are you referring to? I would guess that you mean the one for the Air Conditioner and the Well Pump but I want to be sure.
    Since only one photo was posted I thought it was obvious.

    - - - Updated - - -

    Quote Originally Posted by THOMAS HORNE View Post
    Which of the panels are you referring to? I would guess that you mean the one for the Air Conditioner and the Well Pump but I want to be sure.
    Since only one photo was posted I thought it was obvious.

    All answers based on unamended National Electrical codes.

  15. #15
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    Default Re: Bonding screw

    Quote Originally Posted by Jim Port View Post
    Since only one photo was posted I thought it was obvious.
    Jim, there I found at least three photos looking back through the various posts.

    Jerry Peck
    Construction Litigation Consultant ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  16. #16
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    Default Re: Bonding screw

    The only one showing for me is the Subpaneltowell.jpg.

    All answers based on unamended National Electrical codes.

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    Default Re: Bonding screw

    Jim, look in posts #4 (two photo) and #6 (one photo).

    Jerry Peck
    Construction Litigation Consultant ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  18. #18
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    Default Re: Bonding screw

    Quote Originally Posted by Don McMan View Post
    __________________________________________________ __________________________________
    On the other side of the house there is a box attached to the house,
    that feeds an unattached (detached) building.
    It has buried wire that goes to a cottage type building, and inside to another panel. That panel,
    has 3 20amp fuses, a 15 amp fuse, and a double 20 amp fuse which powers the stove.

    panaeltoCottage.jpg



    The wire that powers this has wire and on the wire there is a date of 2004.
    I believe that's when the wire was made because it is printed on the black wire in yellow.
    Again I have some concerns about this panel.

    Which wire has the 2004 date on it? Is it coming from the double pole circuit breaker in this panel, from the Service Equipment enclosure to the main lugs of this panel, or on both those circuits?

    There is no Equipment Grounding Conductor (EGC) in the feeder that supplies this panel. For a panel in or on the same building as the one at which the Service Equipment is located that is not permissible and hasn't been for many years. Even if the installation is old enough to predate the requirement for an EGC in the feeder to the cottage it is certainly not old enough to not need an EGC from this panel to the service equipment.

    The Feeder which supplies the Panel appears to enter the back of the panel through an unbushed knockout against a bored hole. It has no protection for the feeder conductors which are in the form of individual conductors at the point visible in the photograph. The absence of a cable or raceway connector violates the requirement for connecting either of those to the panel cabinet. That also exposes the wood siding of the building to the heat of any arc or other electrical failure which occurs in that cabinet.

    The feeder conductors which are protected by the double pole breaker; which presumably supply the panel inside the cottage, appear to leave the panel cabinet through separate knockouts. That would violate the requirement that all conductors of a circuit be in the same raceway, cable, or trench. Being in the same trench without a raceway would depend on the separate wires being listed for direct burial. But even if the individual conductors are listed for direct burial they would have to be in a single raceway from were they leave the panel's cabinet down to the 2 foot minimum depth of burial to the top of conductors, the top of the raceway sweep if used, and the bottom of the raceway if no sweep is used were the wires leave the raceway.

    If you will post another photograph, with a wider field of view, that would be very helpful to the folks that are trying to help you bring your installations into compliance with the applicable edition of the NEC.

    --
    Tom Horne


  19. #19
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    Default Re: Bonding screw

    Quote Originally Posted by Dave Ruth View Post
    " what changed prior to 2008 that
    made it OK."

    2 possibilities occur to me:

    1. constant trend since 1897 code, people less tolerant of risk, and code constantly becoming more restrictive

    2. someone figured out that they could sell more wire
    Dave

    The code goes through a continuous process of revision in order to adapt it to court decisions, to keep pace with changes in technology and materials, and take into account the problems identified during the life of the previous additions of the code.

    I was an Electrician for 50 years and an actively serving Volunteer Firefighter and EMT for the same period. During those years in the craft and in public service I personally witnessed incidents which indicated a need for changes in the electrical code.

    For example I attended a call for an electrocution caused by the lack of an Equipment Grounding Conductor (EGC) in a feeder to a detached building. The decedent was using a three wire electric drill in a detached shop. The feeder was inadequately sized for it's loading at the time of the incident. The load on the feeder was markedly imbalanced. The voltage drop in the feeder was very high. The decedent was kneeling on a concrete slab on grade floor when he tried to operate the drill, cried out and collapsed. A coworker had the good sense to pull the cord out of the receptacle. Another coworker mashed down hard on the emergency machinery disconnect not realizing that it had no effect on the convenience outlets. The call to the local rescue squad was made within a minute of the shock. The travel time for the squads ambulance was fifteen minutes. My engine was dispatched as first responder and arrived within 7 minutes of the shock. Engines and basic life support ambulances were not equipped with defibrillators back then so the outcome was set when the shock occurred. Even if his coworkers had known CPR the outcome would not have been any different. If fibrillation of his heart muscle could have been reversed earlier he would have had an excellent chance of recovery. Without that there was no hope.

    The shock which killed the decedent was the direct result of the excessive voltage drop on the neutral and the bonding of the neutral to the Equipment Grounding Conductors in the detached building. The highly conductive slab on grade floor was a much better grounding electrode than the driven rod or rods outside the building. That is why a deadly 3/100ths of an amp flowed through his body and interfered with the organized beating of his heart.

    If the feeder had an EGC there would have been no connection between the EGCs in that shop and the neutral of the feeder, the touch potential of the drill's metal shell would not have been elevated enough above the slab on grade conductive floor to push the 30 milliamperes through his chest from his hand on the drill to his knee on the floor.

    I doubt the incident report ever got seen by anybody on a code making panel of the National Fire Protection Association which is the NECs publisher. Since I was only 1 of the nations 1 million active firefighters I think that it is safe to say that there were more than 1 such incidents.

    I realize that I get wordy when I recount such incidents but even after decades have passed I find that I'm still a sore looser when it comes to having lost a patient.

    Sometimes there is a fairly good reason for spending more on materials then was previously thought to be needed. Keep in mind that it wasn't all that many years ago that Equipment Grounding Conductors were not even mentioned in the NEC. Certainly that was true within my lifetime.

    --
    Tom Horne



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