use of 14/3 wire

[mickeyrory]

I have 14/3 wiring from my panel to a string of lights that end with a switch. I understand why 14/3 wiring was used with the switch at the end of the run but as I looked at the connections at my first light i noticed I had two runs of 14/2 connected in this first box. One was connected to the red hot and one connected to the black hot. It seems to me that besides the real reason they use it in this case it also helps keep the number of wire connections under one wire nut to a mininum. I have been finishing my basement and I need to add some lighting. My question is, can I run 14/3 from my panel for the simple reason that it gives me two hot wires to connect to. Not being an electrician this seems logical to me, however, it also begs the question, "if it was that simple why wouldn't it be the wire of choice over 14/2?"

 

[Mustang51js]

14/3 you can use for two separate circuits,that is if your not getting an inspection or you plan on using arc fault outlets.

 

[NoGarageAtHome]

2 conductor cable is obviously cheaper than 3 conductor... So an electrician is not going to run it if he doesn't have to. I've done it when that's all I had and just capped off the extra wire but it really is a waste.

To answer your question ... Yes you will have two hots ( on separate breakers) they share a neutral and ground.

Remember that you size your breaker to your wire size..#14 wire on a 15 amp , #12 for a 20 amp breaker, 10s for a 30 etc. ...you can go bigger on wire but not smaller on the breaker... A 30 amp breaker may not trip while a #14 wire is being burnt. (The breaker can handle the voltage but that little wire can't)

I stay away from using 14s .. It really is just for light lighting loads or maybe a dedicated plug

 

[sberry]

Many times the red is used as a switched wire.

 

[checkthisout]

I have 14/3 wiring from my panel to a string of lights that end with a switch. I understand why 14/3 wiring was used with the switch at the end of the run but as I looked at the connections at my first light i noticed I had two runs of 14/2 connected in this first box. One was connected to the red hot and one connected to the black hot. It seems to me that besides the real reason they use it in this case it also helps keep the number of wire connections under one wire nut to a mininum. I have been finishing my basement and I need to add some lighting. My question is, can I run 14/3 from my panel for the simple reason that it gives me two hot wires to connect to. Not being an electrician this seems logical to me, however, it also begs the question, "if it was that simple why wouldn't it be the wire of choice over 14/2?"

It allows the running of one less wire. It was common on kitchen circuits. Each breaker must be tied with a common trip handle.

It no longer makes sense because while it did save costs on wiring, it doesn't allow you to use a GFCI or arc fault breaker at the origin of the circuit.

 

[reader2580]

You can buy special arc fault breakers that are common trip for two circuits that share a neutral. They cost about twice what a normal arc fault breaker costs, but you are protecting two circuits.

I was required to upgrade to arc fault breakers when I did a bunch of electrical work in my house including replacing all receptacles, switches, and light fixtures. Two circuits were wired with a single 14/3 cable.

 

[dw1]

It no longer makes sense because while it did save costs on wiring, it doesn't allow you to use a GFCI or arc fault breaker at the origin of the circuit.

But now there is this:
http://www.homedepot.com/p/Southwir...Ground-55048255/203641719#product_description

http://www.southwire.com/news-media/4conductorNMcable.htm

14-2-2, it has a black-white, red-white w/red stripe and a ground, now you can use this for AFCI circuits and dont have to share a neutral.

 

[reader2580]

It would be less expensive to run two 14/2 cables instead of that 14/2/2 unless you have a unique situation. I doubt it really saves much in labor as a pro should be able to run two 14/2 cables at the same time.

 

[dw1]

It would be less expensive to run two 14/2 cables instead of that 14/2/2 unless you have a unique situation. I doubt it really saves much in labor as a pro should be able to run two 14/2 cables at the same time.

I agree 100% $40 for 250' 14/2 and $120 for 250' 14/2/2

 

[justsam]

I suspect the latest NEC requirement to provide a neutral at every switch location, (with some exceptions) have driven the need for 14/2/2, especially if 3 way or more are involved.

 

[checkthisout]

I suspect the latest NEC requirement to provide a neutral at every switch location, (with some exceptions) have driven the need for 14/2/2, especially if 3 way or more are involved.

I should do some research first, but I don't understand how you provide a neutral at every location in a 3 way switch circuit??

Do you just leave it hanging there in the box??

 

[mickeyrory]

Everything in my unfinished basement gets power from this 14/3 wire--not much down there. Are the two breakers used for this wiring usually placed together in the panel? I didn't realize that two breakers were used with this type of wiring. I'm putting 12/2 wiring in for my other needs in the finished basement. I think the reason the 14/3 was used was because the switch for the lights is at the end of the line. Would I be able to replace all of the 14/3 wire with 14/2 for the existing lights, that is, except from the last light to the switch.

 

[checkthisout]

Everything in my unfinished basement gets power from this 14/3 wire--not much down there. Are the two breakers used for this wiring usually placed together in the panel? I didn't realize that two breakers were used with this type of wiring. I'm putting 12/2 wiring in for my other needs in the finished basement. I think the reason the 14/3 was used was because the switch for the lights is at the end of the line. Would I be able to replace all of the 14/3 wire with 14/2 for the existing lights, that is, except from the last light to the switch.

Not sure what you mean?

Lets back up a second here, how many circuit breakers do you have to kill in order stop power from flowing into the box where the 14-3 splits into two 14-2 wires?

 

[RickP]

Everything in my unfinished basement gets power from this 14/3 wire--not much down there. Are the two breakers used for this wiring usually placed together in the panel? I didn't realize that two breakers were used with this type of wiring. I'm putting 12/2 wiring in for my other needs in the finished basement. I think the reason the 14/3 was used was because the switch for the lights is at the end of the line. Would I be able to replace all of the 14/3 wire with 14/2 for the existing lights, that is, except from the last light to the switch.

The previous post by checkthisout is right on point, because it sounds like you might have a multi-wire branch circuit. Was your basement originally wired by an electrician? It just doesn't make sense that a pro would run 14-3 for a single lighting circuit.

If you do have a MWBC, it's possible that the 2 breakers don't have a handle tie, depending on when your house was built. MWBCs were installed for several years before the NEC was changed to require the handle ties. My house was wired like that when it was built in 2005.

Another way to check for a MWBC is by probing the 14-3 wires in the first box. If you have 240v across the two hot wires, it's definitely a MWBC.

 

[wyliesdiesels]

But now there is this:
http://www.homedepot.com/p/Southwir...Ground-55048255/203641719#product_description

http://www.southwire.com/news-media/4conductorNMcable.htm

14-2-2, it has a black-white, red-white w/red stripe and a ground, now you can use this for AFCI circuits and dont have to share a neutral.

Thx for the link. Havent seen that stuff before. Though its a rip off! $137 more for a 250' roll of #12/2/2 vs 12/2.

I should do some research first, but I don't understand how you provide a neutral at every location in a 3 way switch circuit??

Do you just leave it hanging there in the box??

Yes, if u dont need the neutral u can just leave it in the box. Some prefer to put a wire nut on it but thats not necessary..

 

[robert_dean]

Perhaps there was a plan at one time to finish the basement and/or hang a ceiling fan at that location. One of the load leads would power the light portion of the fan separately via a second switch. This allows for the fan and light to be independent of each other.

 

[mickeyrory]

Appreciate the comments. I had to put existing lights in different areas so I had to turn off the power at the breaker. The 14/3 wire entered the first fixture and from there the black hot continued on to power three lights, a sump pump and a radon exhaust fan. The red hot serviced two other 14/2 wires from the first fixture. As "No Garage AT Home" pointed out these "hots" were serviced by two breakers. The breakers were in separate areas of the main panel so were not connected together. I only had to throw the breaker that had the black connected to it because the majority of my work was on the lights. I did have to throw the breaker with the red connection when I replaced the first fixture. Not being an electrician I can only assume that the use of the 14/3 was simply to have these two hots on the same wire; well, it saved running two wires but at construction that wouldn't have been a big deal. The first fixture was only ten feet inside the wall from where the main panel is. I forgot to mention that there was a hard wired smoke detector after the switch so maybe that had something to do with running 14/3 but from what

 

[wyliesdiesels]

U need to fix those breakers. Are they on opposite phases? If not u have the potential to overload the neutral!

 

[mickeyrory]

How can I tell if they are on opposite phases or not? They are on the same side of the panel separated by two other breakers. I'm sure it was how they were originally installed when the house was built in the late 90's.

 

[checkthisout]

How can I tell if they are on opposite phases or not? They are on the same side of the panel separated by two other breakers. I'm sure it was how they were originally installed when the house was built in the late 90's.

The 100% way for you would be to pull the cover off the breaker panel and look.

Follow the lug and see which side of the panel it goes to.

 

[dw1]

If there are two breakers between these two you are ok, do this: at the top of the panel at the top breaker, call it breaker A, next one down is breaker B, go all the way down, A-B,A-B, A-B, A-B, A-B all the way down to both your breakers, you want one of them A and the other B, technically if its a MWBC they should be next to each other on a breaker. Breakers across from each other are on the same leg of the service.

And as Wylie stated above, if they are on the same leg, you have the potential to overload the neutral, you need to move one if the are on the same leg, one A and one B

 

[wyliesdiesels]

How can I tell if they are on opposite phases or not? They are on the same side of the panel separated by two other breakers. I'm sure it was how they were originally installed when the house was built in the late 90's.

Using a DMM, measure the voltage between the 2 breakers at the breaker lugs or the 2 hot legs of the 14/3. If u have 240v then youre good. If nothing then the breakers are on the same phase.

Im not sure what the code was back then as I wasnt an electrician then but I doubt it was code compliant to have 2 separate breakers for a MWBC. My house built in '96, has handle tied breakers for all the MWBC....

What brand of panel do u have?

If there are two breakers between these two you are ok, do this: at the top of the panel at the top breaker, call it breaker A, next one down is breaker B, go all the way down, A-B,A-B, A-B, A-B, A-B all the way down to both your breakers, you want one of them A and the other B, technically if its a MWBC they should be next to each other on a breaker. Breakers across from each other are on the same leg of the service.

And as Wylie stated above, if they are on the same leg, you have the potential to overload the neutral, you need to move one if the are on the same leg, one A and one B

Not necessarily. Depends on the brand of panel...

 

[mickeyrory]

Did a little research on how an electric panel is set up, otherwise I wouldn't know what to look for. Yes, they are on opposite phases. I know this is all very basic to those who are in the trade but to us lay people it is all new. Thanks to all who help out with advice because I not only like to do my own work but I like to understand the WHY of the way it should be done and safety is the number one concern for me at the same time. Again, thanks!

 

[dw1]

Using a DMM, measure the voltage between the 2 breakers at the breaker lugs or the 2 hot legs of the 14/3. If u have 240v then youre good. If nothing then the breakers are on the same phase.

Im not sure what the code was back then as I wasnt an electrician then but I doubt it was code compliant to have 2 separate breakers for a MWBC. My house built in '96, has handle tied breakers for all the MWBC....

What brand of panel do u have?



Not necessarily. Depends on the brand of panel...

Yeah, oops. If you were to have an older panel, ITE Pushamatic (Bulldog) Sylvania (Zinsco) or any panel with one single row of breakers then my above advice would not apply. What kind of panel do you have ?

 

[mickeyrory]

Posted a reply yesterday; don't know what went wrong. I just wanted to thank everyone for the comments and information. I learned a lot between the comments and researching what was said. The two hots are on opposite phases. Again thanks.

 

[wyliesdiesels]

What brand of panel do u have?