Where to place ground wires?

Discussion in 'Electrical Forum discussion & Blog' started by James23912, Nov 29, 2020.

  1. James23912

    James23912 Member

    Joined:
    May 16, 2020
    Location:
    Vermont
    Finally connecting new wiring in house, I will probably see this situation in several as
    Witch boxes, so thought I would ask here.

    I have a 3 gang box for 3 switches in bath, one switch for vanity light, others for fan/light, so there are 3 wires for them as well as a hot line coming in and another line continuing the run, I know what to do with the black and white wires but am not sure on the grounds, my thinking is to connect the in and out lines together and attach each individual ground to the switch that corresponds to the fixtures, does this sound right? I don’t know if you need switch legs for ground wires.

    IOW, attach the ground from the wire going to a fixture to the switch and then attach the other two grounds that are carrying the power
     
  2. WorthFlorida

    WorthFlorida The wife is still training me.

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    Oct 28, 2009
    Occupation:
    Retired
    Location:
    Orlando, Florida
    From this 3 gang box there would be three cables going to the light fixture. The black wire is switched and brings power to the light. The white is connected to the other side of the load (light) and returns to the neutral (white) of the power feed. All four white wires would be connected with a wire nut.


    [​IMG]
     
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  4. wwhitney

    wwhitney Well-Known Member

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    Berkeley, CA
    Make sure you deenergize any circuit before you work on it.

    From your description, each switch should have a grounding pigtail attached to it, and all the grounds (EGCs) and pigtails should be connected together. By my count that's 8 wires: power in, power out, 3 cables for the loads, and 3 pigtails for the switches. Connecting 8 wires together can be challenging. Sometimes it's worth splitting it into two groups of 4, with yet another pigtail joining the two groups. That would mean making (2) 5-fold connections instead of the (1) 8-fold connection.

    Cheers, Wayne
     
  5. James23912

    James23912 Member

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    Location:
    Vermont
    Hi, thanks for he replies, good thing I asked, I was going o do it wrong. I am trying those plug in deals, so far so good, will make it fairly easy to get all those connections together, thanks again
     
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Retired Systems engineer for defense industry.
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    If the box is metal, you need to bond the grounds to the box, then run it to the switches.
     
  7. wwhitney

    wwhitney Well-Known Member

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    In the sense that the bonding path for the box should not depend on the presence or absence of the switches. So either the metal box gets a pigtail, or the EGC from the cable supplying the box could be wrapped around a ground screw in the box before continuing on.

    With a metal box and self-ground switches, the 3 pigtails to the switches could be omitted. A self-grounding device has an extra metal tab on one of the screw holes in the yoke, so that screw provides a grounding connection from the metal box.

    Cheers, Wayne
     
  8. James23912

    James23912 Member

    Joined:
    May 16, 2020
    Location:
    Vermont
    Hi thanks for the responses, all the boxes are plastic and there is no power in the house yet, and I changed the wires yesterday using two of those plug in things, but I am wondering, I was a self employed carpenter for years and often did some demo work, and I have seen boxes in which the grounds are twisted together and crimped and then just one wire is left longer and attached to a ground screw, is that still done and was it legal in the past?

    that is how I have done my outlets, just twisted the 2 grounds together (with crimps), then I leave one longer to attach to the outlet so in essence they are their pwn pigtail, could this be done with multiple grounds? for example, I have some double switch boxes that are end of the line runs so there is just power in and then a line from each switch to a light, so rather than the 8 grounds for 3 switches as in the original question, there are 3 wires total for 2 switches, is that different?

    Hope I am not too confusing
     
  9. wwhitney

    wwhitney Well-Known Member

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    Location:
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    If you use a crimp connector listed for the number of wires you have, and you use a crimping tool identified by the manufacturer for use with that crimp connector, and the geometry lets you leave a few of the wires sticking out long enough to also use as the pigtails, that would be fine. Can you give a make/model of the crimp connectors?

    Cheers, Wayne
     
  10. WorthFlorida

    WorthFlorida The wife is still training me.

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    Occupation:
    Retired
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    Pigtailing connections is more of a local thing or personal preference. For light switch gangs pigtailing with a crimp is really not needed because the load is usually fairly light. Many times the white wire and or black is daisy chained to each terminal on the switches. At lot has to do with the amount of wires and box size, again kind of personal preference. However, wall outlets around a room can have a substantial load such as electric heaters, window AC unit or a rack of electronics and computers. Pigtailing is preferred in my book for outlets because you do not want a heavy load going through the side break off tab. Though the outlet maybe rated for the rated amperage, it is where it can generate some heat and voltage drip. If you have five outlets chained to getter and a heavy load is on the last outlet, that is a lot of connections the current is going through. Good pigtail connections with copper wire to copper wire is a better way. Occasionally I read the 2014 NEC book and there is no code that requires certain type of connection for residential outlets and switches.
     
  11. wwhitney

    wwhitney Well-Known Member

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    FWIW, there's one exception to that rule--the neutral conductor on a multiwire branch circuit (MWBC) can not depend on a device for its continuity, so you have to pigtail the neutral to a receptacle on a MWBC. Of course, with the advent of AFCIs and the extra expense of double pole AFCIs, MWBCs are rarer these days.

    Cheers, Wayne
     
  12. James23912

    James23912 Member

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    May 16, 2020
    Location:
    Vermont
    H again, I may have used the wrong terms, when I re did the grounds yesterday I used the push in type connectors, so it was regular pigtailing, when I said "crimp" I meant those buchanan things or whatever they are called, I was told many years ago to use them.

    I really can't see how connecting outlets the way I mentioned makes much of a difference, it seems like twisting the two grounds together and leaving one longer that connects to the ground screw seems pretty much the same as making an actual pigtail, most of the ones I have seen over the years were done the way I mentioned, but as I have only done a few, I will use the pigtail on the rest, and I have an electrician coming Saturday to do the panel so I will ask him as well.

    Again, there is no power to the house right now, I am very careful with wiring, back in 1979 my cousin , a master , was killed by 440 at a factory, so I am really careful

    Oh yeah, the "expense" of AFCIs, close to 1000 bucks

    I do appreciate the help I have gotten from this place
     
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