I am in the middle of a basement remodel. I have 18 recessed lights that I would like to split on two different switches. Is this to much for one 15 amp circuit? If so and I break these lights into two circuits, can you have two different circuits in the same junction (switch) box to control the lights?
Thanks
Replies
why don't you use those two circuits........ no problem in the same box ........it will provide some lighting if one circuit should trip or need maintenance ?
or some one doesn't try to turn you on while your working on them with a single circuit
You could homerun a leg of 14/3 off the switch box back to the panel. This would give good results.
You are good for 1440 watts on one 15A/120V circuit. Depending on your lamp size you could use just one circuit to the switch and split it to two switch legs. I would not go over 75W bulbs with this method (1350W).
Only one home run to make, and half the wire.
Dave
Code rule up here in Canada is that you may have no more than 12 receptacles or fixtures or combinations thereof on a single circuit. Switches don't count. Don't know what your own rules are. If it were my house, the 14 fixtures would be served with two different circuits.
It looks like I will divide the lights into two circuits. Does anyone know if it is legal to have switches from two different circuits in the same gang box? Potentially, you could open one breaker at the main panel and still have live wires in the box. Do the grounds get tied together or should they be separated by circuit?
....yes you can have two circuits in one box...its a multi-wire circuit if you share the same Neutral...yes you tie the grounds together........yes there will be voltage present if you only turn off one breaker....
YOU SOULD KEEP THE NEUTRALS ISOLATED. A NEUTRAL CONDUCTOR SHOULD NOT SHARE CURENTS FROM ANY OTHER CIRCUIT. BARE GROUNDS SHOULD BE TIED TOGETHER. THEY ONLY CARRY FAULT CURENTS FOR SAFTEY.
MARVIN F. MALM PE(ret)
Again, don't know your local rules, but here in Canada you can run a single piece of 3-wire to supply your 2-gang switch box, with the black supplying one switch, the red supplying the other, and the single neutral serving both circuits. I presume you meant "neutral" when you said "ground", because you always tie the bare ground wires together!
Using a dual breaker with a tie bar between them to serve a three-wire cable is always a good idea, to minimize the risk of having one live and one dead circuit in the box as you've mentioned. That said, I've checked with the local authority and up here the tie-bar connected dual breaker is not code required unless it serves split receptacles. The advantage of doing it with separate breakers is that if you overload one side, you don't lose lights to your entire basement.
If you choose to use separate breakers, you must make sure that the two you use aren't supplied from the same phase (i.e. the same buss bar in the panel), otherwise you'll be overloading the single neutral in your three-wire supply cable! If you don't know what I'm talking about, run two separate 2-wire feeds and keep the neutrals separate in your switchbox. It's a little more work to pull 2 wires instead of one, a little more wasted copper for the extra neutral and ground wire, but given the price of 3 wire versus 2 wire cable it's pretty much exactly the same money. Why that is so is a mystery to me- 3 wire should be cheaper than 2 pcs of 2 wire of the same length!
Thanks for all of your hellp. I think I have a good understanding of what I need to do.
although.....you may want to use two separate boxes if you are considering dimmers...
Don't forget, you can always decrease the amount of load on the circuit by using compact florescent bulbs. That complicates things as far as dimmers go. You can get CF bulbs that will work on dimmers but they are pricey.
Using CF bulbs is good for other reasons too like increasing the amount of light without exceeding the limits for the wire, breaker, cans, etc. not to mention the electricity used.
"Again, don't know your local rules, but here in Canada you can run a single piece of 3-wire to supply your 2-gang switch box, with the black supplying one switch, the red supplying the other, and the single neutral serving both circuits. I presume you meant "neutral" when you said "ground", because you always tie the bare ground wires together! "What do you do in a box that has 3 or 4 3-way/4-way switches in it?You would have different "supply" cables for different switches and each might be on a different circuit.
Correct me if I'm wrong, Bill, but if you still had the supply cable(s) entering the switch box first, it makes no difference whether the switched circuits you're supplying are switched with ordinary, 2-way, 3-way or 4-way switches. What changes is the wiring between the switches and the fixtures (and the other switches). Which circuit each group of light fixtures is supplied by is determined at the supply end. Obviously you need to stay clear of cross-connections between circuits if you have multiple 3- and 4-way switches sharing common boxes.
The point I was getting at is that here in Canada, the only place I even vaguely know the code rules, you are permitted to have circuits supplied by more than one breaker sharing a common box, unless that box is serving a split receptacle. That's what the OP was concerned about when it was suggested he supply his 14 fixtures with 2 circuits rather than one. Supplying more than 12 fixtures with a single circuit would be a code violation here in Canada regardless what the ratings of the fixtures were.
"The point I was getting at is that here in Canada, the only place I even vaguely know the code rules, you are permitted to have circuits supplied by more than one breaker sharing a common box, unless that box is serving a split receptacle."I thought that is what you where saying.But you have a box with multiple way switches in then is very likely that you have circuits being feed from different breakers.In fact with the condition I described to Tim (based on a real house) you have maybe 8 different boxes, each with 2-4 switches that are all "common" in that one each box shares a circuit with one or more other of the eight. Way too many lights and to large any area to be on one circuit.I mapped out the breakers for that house, but don't remember the number, but I think that it was probably 4 different circuits.
"The point I was getting at is that here in Canada, the only place I even vaguely know the code rules, you are permitted to have circuits supplied by more than one breaker sharing a common box, unless that box is serving a split receptacle."
He is talking about the Ontario Code and he's speaking Canadian hence the confusion. We speak the same language so I can tell you what he really meant was you could run two separate circuits in the same box so you didn't have to be concerned about
What do you do in a box that has 3 or 4 3-way/4-way switches in it?
I don't have to be concerned about the situation you outlined since I have a better solution, I always carry a flashlight with me.
here the whole thing would be turned down
Tim
"here the whole thing would be turned down"Why and based on what rules?You have an entrance hall and it in you have a box a the front door with which includes a 3-way for the hall area and 3-way for the stair lights. At the top of the stairs is the other 3-way along with another 3-way for ligths in an upper area office. The other 3-way is at another stairway into the area. And in both of those boxes in the upstairs there are switches for other lights in the area.Now back to the entracne hall it is also controlled by a 4-way at the door from the garage and another 4-way at the first floor hallway. And in that 2nd box is also a 3-way with a switch at the other end. And at the ot her end is switches for lights in that area.At back to the box with the switch for the stairs there is also a 3-way for the dining room lights. The other end of the 3-way at the door way from the kitchen.Are you saying that all of those lights have to be off one circuit or are you saying that in Arkansas that they just have one 100 watt bare bulb with a pull chain and hang in the middle of the house where it will shine in all rooms.
Are you saying that all of those lights have to be off one circuit or are you saying that in Arkansas that they just have one 100 watt bare bulb with a pull chain and hang in the middle of the house where it will shine in all rooms.
LOL, thats funny right there .
Only 12 gauge wire is approved for all living areas serving multiple devices. And you guessed it , 20 amp circuits.
Existing circuits are ok but they cannot be added to without up grading .
Tim
Moltenmetal implies that all of the circuits in a box have to be on the same circuit.I quested that. And mentioned when you have multiple ganged boxes with 3 and 4 way switches in them (indicate that part of that circuit will be in an other box) and when this applies to home with several different places where there are these multiple gang boxes with 3/4 way switches that you are going, end up with at least one box that is feed from several different branch circuits.Your reply was that it was illegal in Arkansas, without givin an details.So my coment was how can you guarantee that all of the interconnected lights will be on one circuit other than limiting the house to one light.
Your reply was that it was illegal in Arkansas, without givin an details.
So my coment was how can you guarantee that all of the interconnected lights will be on one circuit other than limiting the house to one light
Its late and Im not going back to make sure what he said cause were not arguing anyway .
I understod or have the understanding that hes going to be adding on to what he has now .
The problem arose when I inspected a house with 15 amp circuits and they used 14 gauge wire. I started counting outlets and went to the book and found that it was non compliance .[I was self training on the job <G> } Then I called it in and got the meetings and had the state inspector on the job the next morning . I was going to allow it if I could get comfortable with the number of outlets but the code didnt help me there. Neither did the state .
Their reason was the homeowner doesnt know what he or she has and they could tie on to it like this author . Theres power , lets use it . I agreed with that . They could plug in an electric heater and I agreed with that too.
The 14 gauge wire was turned down.
If you tie on to a circuit you must be responsible for the whole thing back to the box or what ever you add to it . Whoever does it needs to address the responsibility.
I didnt go into all that because its probably a moot point , cause its not here. Only cause you asked .
Tim
Sorry if I was unclear, and thanks to TomC for clarifying. That was my point: you are permitted, here at least, to have multiple circuits (i.e. supplied by multiple breakers) in a common box.
yah, why Tim?
Actually, Canadian code, or at least the BC ammendements to the code, allows for the 1440 watt limit for entirely fixed loads like lights. For variable loads like plugs, or mixed loads with lights and plugs, you must stick to the 12 device limit. So if you're using fixtures that are clearly rated for a 100 watt limit you could have 14.
Scott.Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.”
Thanks for pointing that out! Does that apply to permanently-mounted fixtures like ceiling cans only?
I re-read the OP's post and he said 18 fixtures, so no different for him, but good to know for future.
>>>Thanks for pointing that out! Does that apply to permanently-mounted fixtures like ceiling cans only?
I forget the exact code excerpt, but I believe that the rule applies to any fixed load, like heating and lighting (no plugs).
>>>I re-read the OP's post and he said 18 fixtures, so no different for him, but good to know for future.
It would depend on the rating of the fixtures. 18 fixtures each rated at 50 watts would be allowed as long as there are no unfixed loads (plugs) in the circuit. I'll see if I can find a copy of the code this weekend and cite the rule. It's an interesting point that can save a lot of time and money.
Scott.Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.”
Then the calculations are out the window if the OP wants to put all fixtures on a dimmer. The off the shelf dimmers, like Leviton, are rated at 600 watts so if he used 150w bulbs like I did he's limited to 4 fixtures per dimmer and 9 fixtures total on the circuit. That would be 3 dimmers needed per circuit.
Then, if he hunted down the 1000w dimmers at the local supply house, he could reduce the total number of dimmers required but would have to change or add boxes because the heat sinks on those dimmers take up a lot of space. He'd be able to have 6 150w fixtures on one dimmer.
But then he could be using the 95w quartz bulbs and get to put 6 fixtures on one regular dimmer and 15 on one circuit. Go to the 45 w quarts bulbs and he could have 13 fixtures per regular dimmer and 32 per circuit. Those bulbs are bright.
Then during all this playing around he also has to chose the trim to go with the cans and the trim will determine the size of the bulb. And so on.