Wiring for garage lights

garagewiring

I would like to change the light setup in my garage. Right now there is one switch that controls 3 lights, I would like to change to 3 Switchs that controls 6 lights…. 2 lights per one switch, can you show me a simple way to do this

Best Answer

Take power to each switch. Then feed neutral, ground, and a switched hot to each set of lights.

^{Grounds not shown for simplicity}

Related Solutions

Wiring – Light fixture powering other lights / garage door opener

From your description the wiring is normal not "jerry rigged". You can add a new wire to the switch but from the wire count you may not be able to fit everything back in the box and your wire fill would exceed code. It may be better to purchase a 2 gang old work box cut the hole the right size for the box pull the old box and install the new 2 gang box. It may be easier to add a 4x4 box in the attic to make your connections to the outside lights and new feed from the 2nd switch. All connections need to be in a box. The 3 sets of wires in the original switch box are possibly the hot feed, the switched feed to the lights and a hot feed to outlets on the wall this would have been a normal setup a few years back. Remember to turn the power off prior to doing the wiring changes and good luck.

Electrical – Can someone help me make sense of the wiring for these switches

First off -- using a 3 way to sub for a single pole is probably Code, but not the greatest idea

Electrically speaking, there's nothing wrong with using a 3-way (SPDT) switch to substitute for a standard (SPST) switch provided it's wired correctly (or else it simply won't work at all). However, it can be quite confusing to folks who are expecting the switch to have ON/OFF labeling.

You are free to use your three-way switches as a substitute for single pole switches. However, personally, I would play it safe here and get some matching single pole switches to go with your three-way switches to avoid confusion. (Simply take one of the Leviton three-ways you were gifted to the local electrical supply house and ask them for the matching single pole switch. Good spec-grade switches are most definitely worth the money, and are only a few bucks more than builder-grade trash that's the cheapest thing on the big-box shelf!)

The copper bundles should be ground, but whoever wired these switches fails at grounding

You'll need to use bare (or green, although bare pigtails are easier to get in some ways) pigtails from the green ground screws on your new switches to the bundle of bare wires in the back in order to ground them as per 404.9(B) of the NEC, as whoever wired the original switches forgot to put them in, and the plastic box that was used clearly doesn't do anything to provide your switches with a ground-fault current path.

Pigtails beat backstabs

Finally, it's better to pigtail multiple wires together to a single wire that goes to a terminal instead of using the backstab terminals, especially on cheap builder-grade switches as builder-grade backstabs are pretty bad at hanging onto wires. This is doubly necessary in your case, as it appears that the wiring in your box is 12AWG, which the backstabs on your new switches won't accept.

Basically, you want to take the black wire that loops around its terminal on the right switch and goes to the left and wire-nut it with a short length of black wire as well as the other black wire that went to the terminal on the left switch that connected to that wire, and connect the other end of the short length of black wire to the corresponding terminal screw on the new left switch. Repeat with the two wires that go to the other terminal on the left switch, another length of black wire, and another nut, then connect the other pigtail to the corresponding terminal screw on the new switch.

As to why that one wire was sent to two switches? It's the incoming hot feed for both the left and right switches in the box.

Finally, if you need a supply of wire for pigtails, some THHN/THWN dual rated wire will always work. (Random wire might not meet Code by way of not being a type of wire found in NEC 310.104.)