I have some low profile LED light fixtures in my house, and one of them just stopped working. That specific model was recently discontinued, and has been replaced with an updated model. The two models are basically identical. However, when I took the old fixture down and went to install the new one, I noticed a difference...

The original fixture mounted with its two screws directly to the junction box in the ceiling. But the new fixture comes with a metal crossbar for the junction box, and the instruction describe attaching the crossbar between the fixture and the junction box using the two mounting screws.

I understand using crossbars in situations like when mounting holes don't line up, or when suspending a hanging fixture from the center, but those don't apply here.

Is that crossbar really necessary? What purpose does it serve? Why wouldn't you just screw the new fixture directly to the junction box with no crossbar, exactly like the first fixture was installed? Seems like if it was really needed, the original one would have used a crossbar too...

For further examples, here's the instructions for this original model, which show that there's no crossbar involved:



Whereas here's the instructions for the new model, which shows that they're wanting you to install this crossbar between the box and fixture:




What say you?

Nope. Toss it.

Not an electrician, occasional DIYer here.

Not sure we see all the instructions for the new one - at least I don't see where it mentions connecting any wires? The instructions for the old one clearly show/mention the wiring connections - Black/White/Ground.

Reason I mention this - the label for that crossbar is 'GND' which may mean they expect it to be part of the ground connection for the new fixture.

Also, can't tell from the picture whether they expect the wires to be put through a center hole in the crossbar or not. If so, the crossbar might also be part of cable management, fixing the location of the wires inside the fixture.

If not needed for electrical or cable-management reasons, I don't see the point either. But I am not an electrician - will be interested to see official electricians weigh in.

quote:

Originally posted by joel9507:
Not an electrician, occasional DIYer here.

Not sure we see all the instructions for the new one - at least I don't see where it mentions connecting any wires? The instructions for the old one clearly show/mention the wiring connections - Black/White/Ground.

Reason I mention this - the label for that crossbar is 'GND' which may mean they expect it to be part of the ground connection for the new fixture.

Also, can't tell from the picture whether they expect the wires to be put through a center hole in the crossbar or not. If so, the crossbar might also be part of cable management, fixing the location of the wires inside the fixture.

If not needed for electrical or cable-management reasons, I don't see the point either. But I am not an electrician - will be interested to see official electricians weigh in.

sandman76 is an electrician. So I'll be skipping the crossbar for this fixture. Truth be told, I was confident it was redundant and had already installed it without the crossbar last night, but figured it was worth asking here just to be 100% sure, in case there was some oddball edge case use for the crossbar here for which I wasn't aware.

Wiring is just the same as the original fixture: Black/White/Ground.

The fixture isn't intended to be grounded to the crossbar. It's grounded to the ground wire. The GND marking is just mentioned in the instructions to help with orientation, because otherwise some knucklehead would install it with the "hump" pointed downward and then not be able to install the fixture because the crossbar would be protruding below the level of the drywall. (That "GND" stamped on the crossbar denotes the location where you'd attach a green ground screw, if you were to be grounding the fixture to the crossbar, like so: )


But as mentioned, this fixture isn't intended to be grounded to the crossbar, and doesn't come with a ground screw for the crossbar anyway.


The wires aren't intended to be run through the center hole of the crossbar. The center hole of a crossbar is for mounting a center-hanging fixture, like this:

I suspect the crossbar is to make it easier/more secure to connect the ground when using a plastic box.

One time… once, in my career I saw the bar required for “heat isolation”.

It takes 30 seconds to install, why not?