I am replacing two existing 3 way switches. The existing ones did not have a ground attached. The electrical box is plastic. There are ground wires in the back of box that are twisted and crimped together. I am guessing I need to add a pig tail to each of the new switches and connect to existing ground wires. I am trying to figure out the proper way to do this. Any help would be appreciated.

I think I will have the same issue on a row(4) of light switches.




The proper way is indeed to pigtail ground wires from that bundle to each switch. They should be wired in such a way that detaching ground from one switch (to replace it, for example) doesn't impact the grounding of the other switch or anything down the line.

If this makes your bundle of grounds large, you may need to upgrade to a larger wire nut. The wire nut container should have a list of color-coded sizes and the number and gauge of wires it supports.

Side note regarding wire nuts: they should hold every wire very very firmly. Many pro electricians around here note that amateurs don't connect the wire nuts firmly enough and encourage a "yank test": after connecting the wire nut, yank each wire pretty hard. If it comes out, the wire nut isn't connected firmly enough or may be the wrong size.

  • If you don't have wire nuts large enough for all the grounds, put a few together in one nut and a pig tail to another nut where you connect the rest. You'll need a big box and may be hitting fill limits if you need to do that, though. – FreeMan Apr 14 at 17:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.