Random 14-3 wire in my garage

[Dave in Mass]

I was puttering around in my garage this weekend. There is a circular junction box with a single wire running into it. I never paid any real attention to it in the past but this weekend I was looking for a box I could tie a new ceiling light into.

So, I pulled the cover off and sure enough there was just one wire in there. It was 3 wire (3 plus a ground), Red, Black, White, all capped with wire nuts. Doing a little googling, it appears a wire of this size and 3 wires is usually used for a 2 switch circuit or for something that needs two seperate hots (a light and a fan for instance)

My garage is unfinished and from what I can see, this wire goes straight back to the basement to my panel. I have to start flipping some breakers to confirm butI had a couple of questsions assuming it is a single wire from panel to garage ceiling.

1. It is on the ceiling joists of my unfinished attached garage, roughly lined up and about 8 feet in front of the entry door to the house? Any guesses what might have been installed there at one point? (I have garage door openers and ceiling lights)

2. Would this be tied to two distinct breakers in the panel? I am thinking not since there would only be one neutral but then would the red and black be hooked to the same (15A would be my guess) breaker?

3. If I wanted to use this circuit, any issue with just using the black and white and keeping the red capped?

Thanks.

Dave

 

[aandpdan]

Could it be for a smoke or heat detector? That would be 3 wire as well.

Are you sure it goes to your panel?

 

[Dave in Mass]

Thanks for the quick reply. It definitely feeds down into the basement right near the panel along with a bunch of other wires from the garage and the rest of the house meaning, there are a lot of wires above the panel to sort out.

Yuo could be right about the smoke / heat detector. I would say you wouldnt expect to see that in a garage but the prvious owner did have a small dog kennel in there so that is possible.

I get that smoke detectors need to be on all the time and certainly not on a switch but how do they utilze teh 2nd hot wire?

 

[GCncsuHD]

I get that smoke detectors need to be on all the time and certainly not on a switch but how do they utilze teh 2nd hot wire?

In whole house smoke detector setups, the 3rd wire wouldn't be hot, but rather a "communication" wire that goes between the detectors. Typically they just have 14-2 ran to the first detector, then 14-3 ran from that one, daisychained to the rest.

 

[aandpdan]

Yuo could be right about the smoke / heat detector. I would say you wouldnt expect to see that in a garage but the prvious owner did have a small dog kennel in there so that is possible

Actually you should expect to see it, at least in MA. Heat detectors are required in attached garages on homes built after 2008 and many built before then provisioned for it.

Grab a meter. Is the circuit live now? Then turn off the smokes circuit breaker and check it again.

 

[Beemer533]

I was puttering around in my garage this weekend. There is a circular junction box with a single wire running into it. I never paid any real attention to it in the past but this weekend I was looking for a box I could tie a new ceiling light into.

So, I pulled the cover off and sure enough there was just one wire in there. It was 3 wire (3 plus a ground), Red, Black, White, all capped with wire nuts. Doing a little googling, it appears a wire of this size and 3 wires is usually used for a 2 switch circuit or for something that needs two seperate hots (a light and a fan for instance)

My garage is unfinished and from what I can see, this wire goes straight back to the basement to my panel. I have to start flipping some breakers to confirm butI had a couple of questsions assuming it is a single wire from panel to garage ceiling.

1. It is on the ceiling joists of my unfinished attached garage, roughly lined up and about 8 feet in front of the entry door to the house? Any guesses what might have been installed there at one point? (I have garage door openers and ceiling lights)

Could it have been run to a switch previously for a 3-way and then re routed to the panel for some other purpose? There would be no need to run 14/3 from the panel for a 3-way setup, only between lights and switches.

2. Would this be tied to two distinct breakers in the panel? I am thinking not since there would only be one neutral but then would the red and black be hooked to the same (15A would be my guess) breaker?

Yes, it would be 2 separate breakers. If a neutral is shared, the breakers have to be on separate phases and I think the handles need to be tied together...

3. If I wanted to use this circuit, any issue with just using the black and white and keeping the red capped?

I don't see any issue.

Thanks.

Dave

See in red..

 

[Dave in Mass]

Actually you should expect to see it, at least in MA. Heat detectors are required in attached garages on homes built after 2008 and many built before then provisioned for it.

Grab a meter. Is the circuit live now? Then turn off the smokes circuit breaker and check it again.

Thank you. House was built in the 80's but they might have put the house smoke detectors in right before we bought in 2007.

The circuit is definitely live. I will check the smoke detector circuit to confirm that is what I am looking at.

I decided I didn't need the additonal ceiling light after all but we are having our porch screened in, and it would be good to have a couple of outlets and light/fan so I was looking for a circuit for that as well. But that work will be done by an electrition as part of the build so no need to worry about this homeowner frying himself.