14 and 12 gauge wiring problem

[Chip C]

If the light fixture itself is rated as a junction box, then no box is needed in the wall. This usually is the case with fluorescent fixtures into which the cable is led via a small hole; such fixtures have no mounting provision for an octagon box. If the fixture has been made to mount on an octagon box, then of course it ought to have been mounted on one, which would require a much larger hole in the mirror.

Assuming the OP is in the US, he might find a solution using the

12/2/2 cable that I hear is available there; use one pair to feed the receptacle on a 20A breaker and the other pair would junction onto the old 14/2 to go to the light on a 15A breaker. A huge waste of copper and he's already pulled 12/2 to the outlet, so this is not an appealing solution, but it might be a consideration for someone else who's facing a similar spot.

(If the OP happens to be in Canada, he needs to remember that Canadian code mandates 15A breakers on any circuit containing a lighting fixture, even if it's all wired 12-ga.)

To my mind the worst of it is the junction box in the ceiling. That's going to require a cover plate, a monument to the original bad work.

Chip C Toronto

[terry]

On Sep 18, 11:27=A0am, Kevin Ricks wrote:

For the 3 hour explanation. I learnt something. Thanks. Fortunately leaving a low wattage curling iron plugged in plus the short term use of the hair dryer should be fine. Also to my mind there is always difference between something one does temporarily which is 'right at the limit' and something that is not in accordance with code for the long term for use by those who do not understand. For example using a welder intermittently on a too small or too long an extension cord and getting away with it because you have someone else watching. The extension wire is outside in free air and if it did catch fire you immediately disconnect and since you are welding have a fire extinguisher at hand!. Compare that to someone who incompetently hooks up their clothes dryer with wrong AWG and puts pennies in place of blown fuses! Yup seen that! Also seen every appliance in a rural kitchen plugged into the ceiling light socket using a Christmas tree light extension cord! And wondered how with the extension cord getting hot the fridge ever got enough voltage to start! "Yes ma'am that's why the TV goes to about half width each time the well water pump starts". But it's amazing what WILL work at times; just! Was at a home construction area yesterday; three 115 volt extensions across the street, we just drove over them, plugged into one extension box from a completed home! At a glance all thee looked to be the usual

18 or 16 AWG all plugged into another that at best was #12; maybe #14? "Hey boss this skilsaw don't cut too good"! :-)

[gfretwell]

If you really want to get technical, 210.23(A)(1) says

Cord-and-Plug-Connected Equipment. The rating of any one cord-and-plug-connected utilization equipment shall not exceed 80 percent of the branch-circuit ampere rating.

"Continuous load" is not mentioned

[Mikepier]

The 8 light vanity bar light was adhered to the mirror with mastic or glue. The existing wire comes out of the box, through the hole in the mirror, then out through the fixture hole, which has a grommet. Are you saying I can drill through fixture and mirror opening and into the electrical box to make a hole, then just snake the wire down through this new hole and just let it come out of the fixture the way the existing one is doing now? That might be do-able.

[Chip C]

Well, I don't know about making your own hole in the bar. I'd be more comfortable using it as the manufacturer had it certified.

But yeah, as I understand it, if the fixture bar is a totally enclosed box, with a grommeted hole for entry of the romex, then there normally isn't a junction box at all. The cable can run within the wall, out through a hole in the wall (ie, wallboard+mirror), and in through the grommeted hole, which obviously needs to be exactly aligned with the hole in the wall. Then you make the connections to the fixture's internal wiring within the bar, which must be accessible from the front somehow. I've only seen this with fluorescent fixtures but I've never installed a bathroom light bar.

Here's a blog from someone who is replacing such a fixture with one that needs a junction box:

the first picture you can see the cabling emerging from a small hole in the ceiling. This is, I believe, correct, for an appropriate fixture. In this case, there ought not to be (or does not need to be) any junction box in the ceiling at all. CERTAINLY if there is a box there must be no splice made in it, the cable should be continuous all the way back to the prior accessible junction (switch, other fixture, etc.)

My guess is that there is a junction box behind the mirror dating from some original over-mirror fixture; and when the new big mirror went up, they spliced a short pigtail within that box and led it through the hole in the new mirror. See if you can push a long nail through the hole and figure out whether there's a box there or not.

Chip C Toronto

[dpb]

Mikepier wrote: ...

Too many "the hole"'s...I have no clue what the arrangement is or what the objective is any more from this.

But, if the new hole includes a cable clamp that part would be ok.

There's no real provision against adding a hole in an existing box, but it'll be a pita to do it by drilling thru some other small hole and highly prone to damaging whatever else is already in there so that part I'd not recommend.

IIRC this is an outside wall? What's the siding material? If you're adamant you're not going to take this fixture down and access it that way, if it's simply siding of some sort, going in that way isn't necessarily much worse than drywall.

Again, I can't envision what you're trying to do from the above -- a picture somewhere could be worth more than the thousands of words already expended...

--

[Mikepier]

There is a box behind the mirror, I can see it. I wanted to try and push the existing wires inside out of the way, then drill through the grommet hole/fixture/mirror/wallboard and through the box.