New kitchen addition – rough wire phase of construction – inspected job.
Not really an excessive amount of lights, but a somewhat complex switching arrangement to permit multiple lighting options to the HO. Not very may stud bays available for switch boxes due to a more complex HVAC design – return bays and supply ducts everywhere.
Ended up with a 5 gang, 3-1/2″ deep, metal box (~90 cu in) as the main switching center. 10 threaded, factory ground screw holes available.
Ganged switch box will end up with 4 – SP switches and 1 – 3-way switch in it.
Will have 6 – #14 Romex cables entering / exiting – 1 – 14/3 + 5 – 14-2.
My SOP would be to ground the metal box via one ground screw with a tag, then bundle all of the cable grounds + device tags + box tag in one wire nut and distribute to the devices. “Tag” is my term for a short piece of wire.
This would result in trying to wire nut 12 #14 wires together – results would be doubtful – if I can even get a wire nut big enough – don’t really think this is an option.
My thought is to ground the bare conductor in each cable (6) to it’s own ground screw and then bring tags out to each switch’s ground screw – will have to make one double tag since I will run out of ground screw holes.
Open to legal / approved suggestions.
Thanks in advance.
Jim
Replies
There was something similar to this asked a few weeks ago.
What you want to do will work. And probably, in general the best. Trying to bundle a bunch of wires togethere will just add bulk. And with that many you will have to do it in groups and then bundle a pigtail from the groups. More bulk. And you have to push all of those wires back into the box together.
Also depending can use one wire for device ground and daisychain it from device to device.
Or combination of those.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill,
Thanks - I thought it was legal and certainly more practical.
JimNever underestimate the value of a sharp pencil or good light.
Thanks for all of your suggestions.
We passed our rough wire inspection yesterday. The inspector's comment on the gang boxes which came under his close scrutiny - "very neatly done"
Here is the solution which I used on the 5 gang box - there were 5 outgoing cables, one line in, one pigtail to the box, plus 5 pigtails to the individual switches. 12 grounds which need to be connected.
1) I left at least 18" of wire available at the box from each of the cables.
2) From one ground screw in each box; I attached a pigtail for each switch.
3) In a Greenie wire nut, I twisted and nutted: "line-in"; the box ground pigtail; and two of the outgoing cable grounds - the line-in ground was left long and extending through the hole in the Greenie.
4) In a red wire nut, I twisted and nutted: the continued "line-in" ground from the Greenie; an additional pigtail to a second ground screw in the box; and the remaining three outgoing cable grounds. Just for fun I "re-coded" the red wire nut with green tape. Step 3 & 4 provide grounding for all 5 outgoing cables, line in and two pigtails to the box. 7 ground screws total - 3 threaded holes left over.
5) Our switches are allegedly self-grounding when used on a metal box; the pigtails are a case of "belt and suspenders"
- A bit of pre-planning and copious amounts of available wire allowed me to ground everything and only occupy the thickness of a wire nut at the back of the box (3-1/2" deep). Just gotta plan those bends before you cut anything.
- Similar solutions were used for the neutrals and hots.
- All wires tucked back in the box occupy roughly 1" of the available box depth - I think I will be able to get the 4 single pole and 1 three way in the box with plenty of space!
In another part of the project there is a 4 gang box which was handled in a similar fashion.
Answers to some of the comments and suggestions offered:
- I am familiar with the copper ground crimps - but only use them as a last resort - usually when the original wire man left next to no wire in the box - I find a nut is easier to rework in the future - I always try to think about "the next guy" since he is frequently me!
- I loved the ground bar suggestion - probably could have dredged up an old one if I had read the suggestion in time - inspector probably would have passed out in ecstasy if I had used that!
Thanks to all for your replies.
Jim
Never underestimate the value of a sharp pencil or good light.
Have you used the bare copper crimp rings for connecting grounds? They are quick to use and a few large crimps would take care of what you are talking about.
I'm not an electrican, but after watching an electrican use them on a few jobs with mulitple grounds they seemed like the right stuff. On my personal wiring they seem easy to use and worth the price of a pair of dedicted crimpers.
Beer was created so carpenters wouldn't rule the world.
It seems like you have 6 ground wires coming in, one metal box and five switches. These must all be bonded together.
Usually in this situation, you would use a metal mud ring [5 gang by thickness of your wall covering + 1/8"]. If you conducted an autopsy of an old switch, you will find that there is no metal in it except for a couple of brass contacts with the screws and the yoke. When installed, the yoke with bond itself to the mudring which in turn bonded to the box. Technically, this is "wrong" but, on a practical level, it won't make any difference. That is, there is angst that the mud ring may become loose and someone walking across the carpet will develop a static charge, touch the metal, oval-head, 6-32 X 1/2" screw holding on the cover plate and fail to get a shock. When completed, the yoke will contact the mud ring [if it sticks out or is flush with the wall] or even conduct thru the screws. So the switchs are covered.
One of the incoming cables is the power. I like to use that ground wire to loop around the 10-32 ground screw and continue on. The best ground screws are Dottie #1032 TC. So you now have six ground wires to connect together.
As mentioned above, you could use one of those copper tube things or you could use a big blue wire nut or you could get a WAGo with six holes [or two 4 holers] or you could screw part of a ground bar to the metal box. [This will save the cost of the ground screw].
~Peter
spend an extra quarter and get self grounding switches
Why not run the ground associated with the line attached to the box then with appropriate wirenut to the five load grounds and use the self grounding switches.
http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?item=62373§ion=10040
One ground crimp ring should be able to handle the whole bundle quite easily, with your "pigtail/tag" too. Wire nut for that is not practical.