I am installing recessed light fixtures. I need one fixture that has a power circuit coming in to the fixture and two circuits going out of the box to feed other lights.
The fixture says “Maximum of 4 (2 in and 2 out) no. 12 AWG branch circuit conductors suitable for 90 degrees permitted in boxâ€
I am not exactly sure what this means. I am hoping it doesn’t mean I can’t run three cables into this box.
What is a “branch circuit conductor”?
Replies
Sorry, that's what it means.
Does it say anything about 14 guage?
The box in the fixture is fairly small, and by code, this box can only have 4 conductors in it, in addition to the conductors that are part of the fixture itself. This is based on the cubic inches of the box.
The grounding wire is not counted as a conductor, so you can have 2 wires providing power (one hot [black] and one neutral [white]), two wires going out to a further fixture downstream, plus the ground wires, plus the wires that come with the fixture that go to the light socket.
#12 AWG is the maximum wire size conductors you can use in this setup. If you are on a 20 amp circuit your wire size should be 12 AWG. If you are on a 15 amp circuit, your wire size would be 14 AWG, which is also ok.
Suitable for 90 degrees means the wire insulation is rated for a surrounding temperature up to 90 degrees. There are standard ratings. If your wire is rated for a cooler temperature, such as 60 degrees, you can't use it in this fixture because the box gets hotter than that in operation. You can use any wire with a temperature rating of 90 degrees or hotter. If the rating is not stamped on the sheath, it can be looked up in a chart based on the cable type. Your cable might say, for example, "type NM-B". I don't have a chart with me, but another poster might.
A branch circuit conductor is conductor in a circuit downstream of the circuit breaker, and not the conductor bringing power into your house and to the panel. All the wiring in your house is branch circuits except any which provide power to your main panel or any subpanels if you have any.
Yes, the restriction means you can't run three cables into your box. If you have two other fixtures you have to go from the first to the second to the third in line. You can't go to the first and split from there into two.
Damn and blast!
Well that means I have to buy some more wire. I knew getting the light into the hole with three connectors on it was going to be a challenge.
Have to go to the store anyway. Good old Home Depot - missing parts from one of the lights.
I am using 14AWG wire 90 degree wire 15 amp circuit. BTW.
Thanks for the help.
THHN is rated for 90* C.
Don't despair. There is always, well almost always, a way.
If the recess can your installing in an 'old-work' model, one designed to be installed from within the finished space and usually hung off the finish surface you may be in luck.
Old-work cans are removable. This means that the space above them is legally 'accessible'. This means you can install, working through the hole you are going to install the can in, a junction box. A junction box sized to legally accept any combination of wires you care to use.
This is not my first choice of methods. If the area above the can/s is accessible to you, like if there is an attic, a more conventional installation of a junction box, cover and cables would be wiser. Idea being that it is more expected and so easier to troubleshoot if there is a problem years down the road.
If there is no way to get a body up there, as in the case of cathedral ceilings or a floor above, a box accessible through the mounting hole is acceptable according to code.
A trick is to attach the box in such a way as it is easily removable. How you do this will depend on the situation. Some wouldn't fasten the box. I understand the urge but once you get used to the moves needed making it legal is no big deal. It only has to be fastened strongly enough to keep it in one place. A roofing nail tapped in, but not sunk, with a block of iron is adequate.
Run the cables long enough to allow the box to be pulled down out of the fixture mounting hole. This greatly simplifies making up the connections and any later maintenance or repairs. The slack, within reason and neatly tucked out of the way, is of no consequence.
It also helps if you mark the inside of the fixture, only where the trim covers it so the writing doesn't show normally, with a note saying there is a junction box above. All cans fed off that junction box can be similarly marked to say which can the box is above. This greatly simplifies troubleshooting. A Sharpie, particularly the industrial no-fade versions, are good for this.