Lighting – Recessed lighting wiring questions

You probably know this already, but the purpose of a switch is to break the "loop" of electricity that feeds the lights.

Find out where all your wires come from and go to, draw a picture of the circuit and that should narrow down your problem or at least help you in describing your problem to someone who could help you. Drawings are very helpful for issues like this.

From your description, it sounds like the black (hot) wire to the original light was not switched, but the white (neutral) wire was the break in the circuit via the switch. If you wired your can lights up with this in mind, and things still did not work, then there is something else going on that you need to do some investigating to see why your original assumption of where the wires go to/from failed. One of those wires doesn't go where you think it does, or the white/red wire that goes through the switch is not in the same "loop" as the black wire (not likely, nor really possible, but not impossible).

This might be a good opportunity to put the light and the outlets on different circuits. I think that may even be required by code. (ThreePhaseEel suggests that this is only required in bathrooms and kitchens, not necessarily for bedrooms.)

One way to check if you have the same wire (or branch of a circuit) at both ends is to flip the breaker, ground one side of your wire in question to something grounded (pipe, conduit, green ground wire, etc.) and measure with a multimeter that you have 0 Ohms of resistance to ground at the other end (i.e. place one probe on your wire and the other probe on somethign that's grounded...pipe, conduit, green ground wire, etc.). undo the ground and your resistance should go to infinity (or OVLD or something similar). There are also helpful circuit finding tools that would do this same trick...check amazon.

A random check of a manufacturer shows 3-1/2 x 1-1/2 octagon boxes are 11.8 cubic inches. It may also be stamped on your box. You need:

• 1 wire unit for all the grounds
• 4 wire units for your hots
• 3 wire units for your neutrals
• 1 wire unit for the internal clamp
• 2 wire units if a receptacle is inset into that box. If the item is surface mount, 0 wire units.

Total 8 wire units. A wire unit takes 2.0 cubic inches for 14AWG and 2.25 cubic inches for 12 AWG. So that's 18 or 20.25 cubic inches. Your box has 11.8?

You have a few options.

• Add a box extension, a 1-1/2" extension would solve your space problem. Nobody cares which holes the wires come in, I never use knockouts in extensions because then it's hard to remove.
• Put a second nearby box to offload some of the wires.
• Convert to a 4" square box (21 cu. in.) with a mud ring (? cu. in.)giving a face similar to a 3-1/2" octagon box. This may also help you address your depth problem mentioned in the other post. It's ridiculously easy to change boxes since all your wires are flexible and terminate in the box. (by "ridiculously" I'm contrasting it with thru wires which must be pulled, steel conduit, substituting a wider box so you have to cut the conduit, and doing it 21 feet in the air in a boom lift!)