Lights on metal ceiling

[Cb-man]

I am getting stuff around to wire up my pole barn. I plan to use metal panels for the ceiling. The electric in the walls will be run behind the walls.
I am curious about wiring in the ceiling for Fluorescent lighting,
what did those with a metal ceiling do? Mount a box to the truss and cut a hole in the metal? put a build out junction box on the wall near the ceiling and run conduit?

 

[UpstateNY]

Just stub armored cable thru ceiling. No need for a box per code, the fixture is the box. Run short surface mounted EMT between fixtures.

 

[Mustang51js]

If you don't want to see pipe then you would have to see where the knock outs are on the back of the light and stub bx or mc wire out in those spots, it's definitely more work

 

[Doug Arthurs]

I to just ran by and left it hanging until my lights went in. The fluorescent don't need a junction box. I had to relocate one light due to my poor planning and mounted a junction box and then used emt to get to the new location. I painted it all white to blend in with the ceiling.

 

[jomobco]

There are 2x4 supports running between my truss which were put in to mount the fluorescents to. No box needed as others have said.

 

[Cb-man]

I don't know a lot about wire so what is bx mx? Armoured wire?
So you just drill a whole in the metal and bring wire into the fixture?
If running 2 or more lights on a circuit do you just tie in the wires running to the next light in the first fixture? or use a junction box to continue on to the next light?

 

[alfredeneuman]

BX is a thing of the past, and hasn't been produced for many years.

The 2 types of armored cable most commonly used today are type MC (metal clad), and type AC.
They both are pretty much the same, but MC has a ground wire in it, and AC depends on a thin aluminum strip in intimate contact with the armor for grounding.

Depending on the circumstances, Romex could used just as well, if the lights are directly mounted to the ceiling.

 

[Charles (in GA)]

Depending on the circumstances, Romex could used just as well, if the lights are directly mounted to the ceiling.

Just drill a clean hole of the right size and install a plastic bushing in the hole for wire protection.

Charles

 

[Mustang51js]

I don't know a lot about wire so what is bx mx? Armoured wire?
So you just drill a whole in the metal and bring wire into the fixture?
If running 2 or more lights on a circuit do you just tie in the wires running to the next light in the first fixture? or use a junction box to continue on to the next light?

If you did decide to use a metal cable you would need the proper connector for that cable,but they make double connectors so all you would need is one hole and both wires would come from that hole, then in your light fixture there will be stamped circles that you would knock one out and that's where the connector goes into. Just make the hole in the metal ceiling is big enough that the connector fits back up when you mount the light to ceiling. You would be daisy chaining the wires from one to the other.

 

[NUTTSGT]

I'm guessing that you are using white panels.

I'd bend some sheetmetal standoffs to attach the lights to the ceiling. Basically an inverted "square" U, which would allow you to screw the "U" to the strip lights and the flat to the ceiling. When it came to the wiring, I'd use a terminal adapter, lock nut and a section of PVC conduit to stub up through the ceiling. Paint the conduit white if you're considered on looks or run it up through the standoff to conceal it.

Of course, you'll need a corresponding hole in the ceiling for the conduit.

 

[Highbeam]

Just drill a clean hole of the right size and install a plastic bushing in the hole for wire protection.

Charles

Those look great for the ceiling but you need the same sort of thing to go into the metal fixture and if you are mounting the fixture tight to the ceiling then there isn't room for two without nesting one inside the other somehow.

 

[mygarageone]

Can't you install it through the light fixture too ?