electricallight-fixturelightingwiring
I have a round junction box protruding from an exterior wall. It had a fixture on it with a circular cover, but I've replaced it with a fixture that has a rectangular box which I would guess is supposed to be tight to a wall (see photo).
The area where this is installed is covered, but there is free airflow into the junction box and I can see the wires if I poke my head back there.
Are there any risks to having this wiring exposed in this way?
The correct answer is: Redo the wiring all the way back to the panel.
The workable answer is: The wire with the black stripe on the insulation is BLACK. The other one is white. The junction box is probably not grounded, but I'd attach the ground wire of the light to the junction box anyways.
Safety wise, the ground isn't entirely necessary on a ceiling light as it is pretty unlikely that anyone will touch it.
But seriously, consider replacing the wire right back to the panel. It can be a pain to pull it, but modern wiring is much safer.
Strictly speaking, that round metal mounting bracket on the back of the fixture is supposed to be secured to an electrical box.
It can be a shallow box, but it's supposed to be a box. You must protect the wires. You want that new garage to still be there 10 years from now.
I can't really tell from the photo, but the right shallow metal box should fit within that recess on the back of the fixture without you needing to cut a hole in the siding. But if you have to cut a hole, then you have to cut a hole (if you do, rent, borrow or buy a holesaw for your drill big enough for the box).
You could attach the box through to the OSB with screws, although personally, I'd lay a 2x4 flat side against the OSB inside the garage, toenail it into the studs on both sides, and screw the box directly through the OSB into that 2x4. So a stiff breeze or errant basketball doesn't knock your light fixture off the wall. :-)
Drill a hole through the OSB and the 2x4 big enough to feed the cable and to accommodate the clamp that holds the cable in the box. The cable has to be clamped into the box.
Then attach the round mounting bracket that came with the fixture to that box, wire everything up, attach the light fixture to the bracket that you attached to the box. That's the way it's designed.
If it's a metal box, it has to be grounded (screwing the grounded mounting bracket to it will accomplish this).
You also have to secure the cable inside the garage as dictated by your local electrical code.
Finally, I'd use a dose of waterproof silicone or caulk around the box, and then again around the fixture itself after it's mounted, to make sure water doesn't seep inside.
Good luck!
Best Answer
That needs to be closed up. Use a round to rectangle box adapter.
Image from amazon, no endorsement implied, it was just the first one to come up and I'm being lazy.