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  1. #1
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    Default Double Tap and Bundling Madness

    I counted 12 double taps in this panel which is a record for me. And every cable was brought into the box through the 4 main holes at the top of the box.







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  2. #2
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    Default Re: Double Tap and Bundling Madness

    Nick are you sure those breakers don't allow two wires? I can't tell from the photo but it looks like it might be one of the few that has provision for two wires.

    Jim Luttrall
    www.MrInspector.net
    Plano, Texas

  3. #3
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    Default Re: Double Tap and Bundling Madness

    They were not Jim. I looked closely at the breakers and they did not have double lugs, only a single round hole for the conductor connection.

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  4. #4
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    Default Re: Double Tap and Bundling Madness

    Good chance you have a derating issue with the supper bundling. Connectors most likely are not listed for that many wires under there. Siemens QP breakers are not rated for 2 conductors under 1 terminal if Im thinking of the correct listing for QPs.


  5. #5
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    Default Re: Double Tap and Bundling Madness

    Just trying to learn a little something here. How many wires can you put through one connector? I'm sure the different size connectors are rated for a different number of conductors/wires based on their size, but is there a general rule of thumb?

    Thanks

    Luke


  6. #6
    Mbrooke's Avatar
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    Default Re: Double Tap and Bundling Madness

    Quote Originally Posted by lukerabun View Post
    Just trying to learn a little something here. How many wires can you put through one connector? I'm sure the different size connectors are rated for a different number of conductors/wires based on their size, but is there a general rule of thumb?

    Thanks

    Luke
    Its usually up to the listing of the device, sometimes the NEC. The number of wires on a breaker is based on the listing of the breaker. Most only can take 1, however Square D QO and Square D Homeline 15 and 20 amp can take 2 copper conductors of the same size if placed correctly on the screw plate. Neutral bars are always 1 per hole, ground can take more if the panel board says its ok too.

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  7. #7
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    Default Re: Double Tap and Bundling Madness

    What does derating actually involve?

    "It takes a big man to cry. It takes an even bigger man to laugh at that man". - Jack Handey

  8. #8
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    Default Re: Double Tap and Bundling Madness

    Quote Originally Posted by Nick Ostrowski View Post
    What does derating actually involve?
    To keep it simple it involves keeping the conducters spaced apart, ie entering different holes and not huddled together so tight in large packs.

    Similar procedure followed with conduit. If more wires are put in conduit those wires are either sized larger or put in another conduit to keep the overall count low.

    Issue comes from overheating. Less of a risk in residential as appose to commercial where circuits are loaded more but still not up to code.


  9. #9
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    Default Re: Double Tap and Bundling Madness

    Since the conductors do not have the space to radiate the heat when grouped together the code makes an installer derate or lower the ampacity of the conductors from the Table 310 chart. The more conductors the less they are allowed to carry.

    Derating is not an issue when the conduit or nipple is 24" or less in length.

    All answers based on unamended National Electrical codes.

  10. #10
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    Default Re: Double Tap and Bundling Madness

    Quote Originally Posted by Jim Port View Post
    Derating is not an issue when the conduit or nipple is 24" or less in length.
    Thanks, Jim.

    Forget bundling and nail him for double taps.

    Cutler Hammer also makes a breaker that can take two wires. Square D or CH only.

    John Kogel, RHI, BC HI Lic #47455
    www.allsafehome.ca

  11. #11
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    Default Re: Double Tap and Bundling Madness

    Quote Originally Posted by lukerabun View Post
    Just trying to learn a little something here. How many wires can you put through one connector?
    Typically two with #12 or #14


  12. #12
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    Default Re: Double Tap and Bundling Madness

    Quote Originally Posted by lukerabun View Post
    Just trying to learn a little something here. How many wires can you put through one connector? I'm sure the different size connectors are rated for a different number of conductors/wires based on their size, but is there a general rule of thumb? Thanks Luke
    Luke,

    If I understand your question correctly, you are referring to the number of cables that can exit through an opening in the panelbox. That, too, is up to the listing/manufacturer. The strain relief clamps typically allow 2 flat (2 wire + ground) or one round (3 wire + ground) through an individual opening.

    Department of Redundancy Department
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  13. #13
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    Default Re: Double Tap and Bundling Madness

    Any thoughts about the painted cables? Looks like all yellow sheathing inside then white on the outside, guessing it was painted, or am I seeing an optical illusion?

    One thought is if they are painted are you sealing them all together, no chance of air moving through, creating a pseudo conduit situation, unless the bundle is under 24" then it's not an issue.

    Other opinions???



  14. #14
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    Default Re: Double Tap and Bundling Madness

    You are correct Mike. The cable sheathing was painted.

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  15. #15
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    Default Re: Double Tap and Bundling Madness

    Hey Nick, I see the neutral bars but don't see any ground wires from all the branch circuits going anywhere. Were they cut off or are they hidden and the photo doesn't show them? Just wondering.


  16. #16
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    Default Re: Double Tap and Bundling Madness

    Quote Originally Posted by Mike Borchardt View Post
    Hey Nick, I see the neutral bars but don't see any ground wires from all the branch circuits going anywhere. Were they cut off or are they hidden and the photo doesn't show them? Just wondering.
    The grounds are there. Just tucked behind the bundles.

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  17. #17
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    Default Re: Double Tap and Bundling Madness

    Can barley see it behind the wires but there are extra ground bus bars

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