Another quick wiring question

[kyle242gt]

Hi all -
I have 15 light fixtures, .74a each, which is within the limits of a 15a circuit.
Presently, there are four banks of lights, 6, 4, 3, 2.

However, I figure better safe than sorry, and it's a lot easier to overkill the first time around than to fix it later.

As the lights are all on 14ga, I need 14ga/15a feeds from the panel.

Can I run one 14/3 from the panel, and have one leg feed two banks and the other feed the other two? Or do I need two 14/2 runs with separate neutrals?

Many thanks!

 

[jasonreck71]

That is fine...I have 4 banks of 4 can lights on 1 circuit in my garage..I ran one "hot" wire from the panel into a box with 4 switches then from there went to the 4 banks of lights

 

[kyle242gt]

Thanks for the rapid reply, Jason-

As always, I suppose more info is in order. If my 1000sf garage is divided in two, I have 13 of the lights on one side, two on the other. I figure that's fine for now, it's got a couple windows and will just be for parking and storage.

However, I have these fantasies of putting in a temporary spray booth over there, and will need lots more light. If I add another five or six fixtures, I'll be right at 15a. Admittedly I won't have everything on at once, other than to impress people and make the utility co happy.

 

[Falcon67]

I'm lighting 960 sq/ft in two sections. I just did two light circuits on different breakers. The work area (12x24) has 4 8' lights in banks of two plus the bench lights and the shop area (28x24) will have 8 ea 8's in four banks of two. If I have to work on one circuit, I still have light in the shop.

 

[kyle242gt]

We're on the same page, Falcon - do you feed that with 14/3 or two 14/2? Just need to know if each circuit needs a separate neutral.

Something tells me that if both hots are in use, there's no load on the neutral. And if I have only one hot going, the one neutral is sufficient.

 

[rwreuter]

you can use the same neutral.....though they need to be on different phases in the electrical panel....

do you understand the phase set up in your panel?

if you don't.....just put one breaker on top of the other and they phases will be split.

 

[kyle242gt]

Thanks for the reply RW; the breakers are doubles, which I assume (and will verify) are separate phases.

 

[pattenp]

I must be missing something here. What's the purpose or benefit of running a multiwire branch circuit (using 14/3) for your lights. A MWBC will require a 2 pole breaker (you can't use 2 single pole breakers), so if one bank of lights trip for some reason the second bank will also go off. Why not have one circuit and wire it as multiple feeds from the switches?

If you want your lights on 2 circuits then put it on 2 separate circuits. Do not do a MWBC.

 

[kyle242gt]

Hey, I'm all ears!

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

Tandem 15a, I don't see a lock between the poles. That said, I'm not overly concerned about having separate trips, just a way to have some room to grow if I need more lighting.

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053
Is a full size double breaker; I take it this would require two 14/2 runs?

Same drill here, I take it, I have two of them (don't know why I would?)
http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

I like the tandems to save space in the panel... but I still have plenty of extra slots, so whatever works best...

 

[porcupine73]

You definitely can NOT do a mwbc with that first breaker you linked. That is a tandem breaker, not a double pole breaker. Both circuits off that breaker are off the same phase in the panel. You cannot share the neutral there.

If doing that, and wanting to use two circuits, I would just run two 14/2 instead of one 14/3. Then you don't need a double pole breaker either (unless maybe both circuits run into the same box with the switches, not sure on that), so if one trips you don't lose all the lights. Doing it all on one circuit, as you say .74 amps each using 15 of them, actually does not leave you much room for expansion at all, considering the typical 80% rated breaker and 'continuous (3 hours or more)' loading limitation.

 

[kyle242gt]

Gotcha.

I can either use a tandem with two 14/2 runs (saving space in the panel at the cost of running an additional neutral) or a double (or two singles) with a 14/3 run.

 

[pattenp]

Gotcha.

I can either use a tandem with two 14/2 runs (saving space in the panel at the cost of running an additional neutral) or a double (or two singles) with a 14/3 run.

You can not use 2 single pole breakers to feed one 14/3. To feed 14/3 you have to use a 2 pole breaker where the two switches are mechanically connected (second picture). Its the same type of breaker that is used on 240V circuits. You should run two circuits using two 14/2 on two separate single pole breakers or on one tandem single pole breaker (first breaker picture) and be done with it.

 

[porcupine73]

Also make sure your panel is listed to take the tandem breakers.

 

[kyle242gt]

(doh) I knew that about the 14/3 on the two singles, don't know what I was thinking.

Sounds like tandem (yes, box is okay for that) is the way to go.

Thanks again for the help, everyone!!

 

[Falcon67]

Everything in the shop is 12-2 w/g except the heater, which requires 10-2 w/g. I'm close to 500' pulled. It goes quicker than you think. For light circuits, I run power to the switch box, then jumper the hot to all the switches on the same side of the switch. You end up with all the neutrals and grounds twisted and pushed to the back of the box and just the hot wires from each light bank to mess with.

I was going to run some 12-3 for a three way switch to operate one bank. I have 28' of floor between the man door and the work area at night. I'm not all that decided that it's worth the cost of the wire. I have three 3' dual bulb fluorescent emergency lights to install and I now plan to buy a flo bulb compatible motion switch to light one on entry.

 

[pattenp]

kyle242gt, one code thing you may not be aware of. If you end up having any switch boxes that just contain switch loops you also need to have a neutral to that box even if it's not used. This is where you'd use 14/3 to get the neutral.

 

[rwreuter]

You can not use 2 single pole breakers to feed one 14/3. To feed 14/3 you have to use a 2 pole breaker where the two switches are mechanically connected (second picture). Its the same type of breaker that is used on 240V circuits. You should run two circuits using two 14/2 on two separate single pole breakers or on one tandem single pole breaker (first breaker picture) and be done with it.

you DO NOT use a pole breaker....that is 240v....you use 2 single pole breakers, one on top of another, each breaker will give you 15a, 1800watts. more than enough to operate the lights you are looking at.

in fact you could get away with one single pole breaker.

 

[rwreuter]

Hey, I'm all ears!

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

Tandem 15a, I don't see a lock between the poles. That said, I'm not overly concerned about having separate trips, just a way to have some room to grow if I need more lighting.

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053
Is a full size double breaker; I take it this would require two 14/2 runs?

Same drill here, I take it, I have two of them (don't know why I would?)
http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

I like the tandems to save space in the panel... but I still have plenty of extra slots, so whatever works best...

use 2 of the third breaker....land the black wire on the first one and the red on the second one and the neutral and ground on the bus bar.

DO NOT USE EITHER OF THE FIRST TWO....DO NOT!!!

 

[rwreuter]

using the first breaker (tandem), the neutrals will be on the same phase and the neutral will eventually melt. bad juju.

the second breaker is a 2 pole 15a (240v) breaker....not designed for what you need.

using the 3rd breaker (on opposing phases) is the correct one. the only way to ensure that if you do not know what you are doing is to stack them one on top of another.

 

[kyle242gt]

Thanks again for all the great help guys. Lots of good info in here. After the discussion, I think I'll just to two 14/2's on a tandem 15a. It's not that long of a run to the panel, and I have lots of wire left over.

I guess my electrician is used to other people buying the wire, I have about 200' of 14/3 left over. "Just get a whole roll" he says...

 

[pattenp]

If you use two single pole breakers on a MWBC you are in violation of NEC 210.4(B)
You have to put handle ties on the two singles to comply with code.

you DO NOT use a pole breaker....that is 240v....you use 2 single pole breakers, one on top of another, each breaker will give you 15a, 1800watts. more than enough to operate the lights you are looking at.

in fact you could get away with one single pole breaker.

 

[rwreuter]

that section is referring to using a 2 pole breaker.....


Where two or more branch circuits supply devices or equipment on the same yoke, a means to simultaneously disconnect the ungrounded conductors supplying those devices shall be provided at the point which the branch circuits originate.

 

[pattenp]

I corrected the code section, its 210.4(b) not 210.7.

 

[rwreuter]

ok, the new code referrence.....

this is making it illegal to land a 14-3/12-3/14-2/14-3 or greater on a 2 POLE BREAKER and using each circuit as a 120v individual branch circuit rather than 240v.

 

[kyle242gt]

Does that mean, in layman's terms, that:
you can't use a double pole for two 120's
you can's use two singles for 240
?

 

[rwreuter]

yes

the two 120v....have to be on a single pole breaker, each on their own breaker

for example.....240v air compressor.......2pole 15a or 20a breaker (like your second picture...there has to be a tie so if one leg has a fault both will shut off and protect the user (safety)

for example......12-3....there are 2 small appliance circuits in your kitchen, chances are they are run from a 12-3...circuit A and circuit B....each are 120v and each land on a single pole 20a breaker on different phases.


houses all over america are using 14-3/12-3, black on one breaker and red on another.....i would be 1 bazillion dollars your house has it and i am surprised that pattenp's house does not. (just a few minutes ago i was looking at his breaker panel)

not to pick at him...but his breaker panels are in violation of the NEC.

funny thing....i actually did this for a living.....

 

[pattenp]

Where are you getting this from? I'm looking at NEC 2011 210.4.

ok, the new code referrence.....

this is making it illegal to land a 14-3/12-3/14-2/14-3 or greater on a 2 POLE BREAKER and using each circuit as a 120v individual branch circuit rather than 240v.

 

[kyle242gt]

Haha, you'd be surprised how my house is wired. 1957 construction, 1971 upstairs addition, 1980's kitchen remodel (wherein they stole the 220V to the garage for the candyass electric range). All on lovely Zinsco breakers.

That's why I said "F-it" and had 100A run to the garage. At least there all the screwups are my own.

Used the opportunity to install a new main panel and get rid of the Zinsco stuff too. Remind me again why I bought an old (by Ca standards) house?

 

[pattenp]

So how is my Cutler Hammer CH panel not NEC compliant?

yes

the two 120v....have to be on a single pole breaker, each on their own breaker

for example.....240v air compressor.......2pole 15a or 20a breaker (like your second picture...there has to be a tie so if one leg has a fault both will shut off and protect the user (safety)

for example......12-3....there are 2 small appliance circuits in your kitchen, chances are they are run from a 12-3...circuit A and circuit B....each are 120v and each land on a single pole 20a breaker on different phases.


houses all over america are using 14-3/12-3, black on one breaker and red on another.....i would be 1 bazillion dollars your house has it and i am surprised that pattenp's house does not. (just a few minutes ago i was looking at his breaker panel)

not to pick at him...but his breaker panels are in violation of the NEC.

funny thing....i actually did this for a living.....

 

[rwreuter]

each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit orginates.

simultaneously.......2 pole breaker...ie 240v circuit

 

[rwreuter]

picture 2 of 4....you have white wire (10gauge i think) landed on 2 pole breaker. in ahhhh 4 locations

minor violation.....

another thing...not sure about it though, i would have to look it up and also see where the panel is located in reference to the main....there is no disconnect in that panel.

 

[kyle242gt]

picture 2 of 4...

not seeing pics on my end, are they in another thread?

 

[pattenp]

picture 2 of 4....you have white wire (10gauge i think) landed on 2 pole breaker. in ahhhh 4 locations

minor violation.....
White is marked with red tape. Passed code when inspected. One picture is old before marked with red tape and prior to inspection.

another thing...not sure about it though, i would have to look it up and also see where the panel is located in reference to the main....there is no disconnect in that panel.

That sub panel is in the attached garage and does not need to have a main breaker. Passed inspection.

 

[pattenp]

Pictures are in my profile.

not seeing pics on my end, are they in another thread?

 

[rwreuter]

click on his name, you will see his profile, on the profile you will see something that says "show all albums"....then click on the one with the electrical panels.

i like his garage with the lift in it.....

when i had my house built, i set the lot so i could have a detached garage and it could be connected by a covered walkway. it wouldn't look like an after thought. i have 6.5 acres, so i have plenty of room.

not sure of his ceiling height....14'? mine is 12, so i am not sure if i have room for a lift. am wondering what that silver tube is hanging from the ceiling....HVAC?

 

[pattenp]

Garage ceiling height is 12' 6". Silver tube is exhaust for my home made portable AC unit. There is a fire rated exhaust fan in the ceiling. Other tube fits in window for air intake.

 

[pattenp]

Here's a good explanation of MWBC: http://www.homeinspector.org/resources/journals/Multiwire-Branch-Circuits.pdf

 

[rwreuter]

though old, it is correct...............the black and the red are on opposite or different phases and each are on its own single pole breaker.

not sure where you are getting confused.

 

[pattenp]

I'm not confused. I'm just saying that the single pole breakers have to be connected with handle ties. I'm getting this from 240.15(B)(1).

 

[rwreuter]

as long as that single pole breaker is identified they don't have to be tied together if they are sharing a neutral

it is still NOT illegal to use 2 single pole breakers for a 14-3/12-3.