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Can I connect a 3 way switch to be used as a single pole? I accidentally purchased a couple of them and only need to control one light each.

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    There was a similar question previously that I'm not finding right now, that question before I believe asked If NEC addressed whether a 3-way switch could be used when only a single pole switch was necessary. If anyone knows how to find that question please link it. – Tyson Jan 16 '17 at 22:30
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    I did it today and it worked so rest assured it's possible. I left one of the two brass screws unconnected – Dan Mantyla Jan 17 '17 at 7:44
  • It is legal and possible to use a 3 way switch as a single pole switch just check the listings they are listed as a 3 way dpst or a standard on off spst. Since they are listed as such the NEC section that says must install according to manufacture instructions would eliminate any need to look in the NEC. – Ed Beal Feb 24 '18 at 3:30
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Yes, you can use 3-way (UK: 2-way) as 2-way (UK: 1-way) switches. It will work fine. Simply make sure the screws are different colors; you want the common terminal and one of the messengers; not both messengers.

You can do the same with a 4-way (UK: the kind that goes between two 2-ways), again choose screws of different colors, i.e. one from the upstream "side" and one from the downstream "side". They are not necessarily on the same physical side.

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Yes it can work. 3-way switches are spdt (single pole double throw) with 3 screw terminals, and regular switches are spst (single pole single throw) with 2 screw terminals.

Just pick the correct two contacts and you are good to go. .

If there are two on one side and just one on the other, then connect to the one that is alone on one side, and either of the other two on the other side.

A multimeter is the quick way to figure out which terminals to use. Just set it for ohms and you will be able to tell what happens as you toggle the switch.

  • Usually the common is black and the travelers are copper. Or silver colored. – Ed Beal Feb 24 '18 at 3:32
  • Regarding "If there are two on one side and just one on the other, then connect to the one that is alone on one side, and either of the other two on the other side." This advice does not work in all cases. I have brand new switches here where it definitely won't work: one side has a black and a brass screw and the other side has a brass screw. (The screws were correctly installed. I checked with a multimeter.) However, the advice by Harper (connect to two screws of different colors) works for every single switch I have in my stock of switches. – Louis Nov 3 '18 at 12:43
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You will have two Common screws. They will be across from each other on the switch. If you look at the switch it will identify both of them it will say common and there will be an arrow pointing to them. Then above one of the common screws you will have another screw. Wire the hot feed coming in to the common on the same side of the switch as the screw which is above. Then wire the hot feed going to the fixture to that screw that is on the same side as the common you just wired in. Twist your bear grounds together and hook them to the green screw. The reason this works and is okay is because as a single pole switch has two screws on the same side of the switch. All you're doing is eliminating one of the commons that the traveler would go to. It is not dangerous for this reason.

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Yep! 3-way switches can work just fine as a single-pole. You'll just have a couple of poles open.

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    I'm not sure what you mean by "You'll just have a couple poles open", did you mean to say, "you'll just use 2 of the 3 terminals, one terminal will remain unused"? – Tyson Jan 16 '17 at 22:24
  • @Tyson yes, what he means is that is that one of the two hot connectors will go un-used. A "pole" is electrical component jargon i.e. spdt is single pole double throw, google it for more info – Dan Mantyla Jan 17 '17 at 7:41
  • @DanMantyla trust me I know, you missed the hint of sarcasm apparently. – Tyson Jan 17 '17 at 15:02
  • While it may be technically correct, the answer doesn't really explain why it's correct and not dangerous to use what is technically the wrong part for the job. Answers should endeavor to explain they WHY along with the WHAT. – The Evil Greebo Jan 18 '17 at 14:30

protected by Community Aug 26 '18 at 21:43

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