For all you troubleshooters...

[1793]

About three months ago I go to a customers house to replace some ceiling luminaries. One I replaced had a plastic nail-on device box, no big shakes, I put up the new luminaire, see below.

A few weeks later I get a call that one of the luminaries has come loose from the ceiling. Customer tried to put it back up with no luck. I get there and put it back up. This time I use washers not knowing if the mounting screws pulled through the slots in the luminaire and or bridge. After I put the luminaire back up I gave it a good tug and it was tight to the ceiling.

I get a call three days later, yesterday, that the same luminaire is falling down again. I get there today and the luminaire is hanging by one of the 6/32's x 2" screws and the head was about 1" down from the ceiling and the other screw was completely out of the box.

I now have a theory as to why this luminaire keeps coming down how about any of you?

 

[chris kennedy]

I get there today and the luminaire is hanging by one of the 6/32's x 2" screws and the head was about 1" down from the ceiling and the other screw was completely out of the box.

You can't hang a ceiling fixture from a device box and 6/32's. See 314.27(A).

(see the exception where that is allowed on walls)

 

[Bobhook149]

You can't hang a ceiling fixture from a device box and 6/32's. See 314.27(A).

(see the exception where that is allowed on walls)

Damn, you beat me too it!.... Yeah what he said.

 

[1793]

You can't hang a ceiling fixture from a device box and 6/32's. See 314.27(A).

(see the exception where that is allowed on walls)

This I have now corrected, one of those things you forget about. But why did the luminaire come down?

 

[Sierrasparky]

You can't hang a ceiling fixture from a device box and 6/32's. See 314.27(A).

(see the exception where that is allowed on walls)

Not that I would ever do that. I did have an argument with a fellow EC about that very same issue. He said there was an exception for the ceiling if the luminare was under a certian weight. I argued that it is an acciden waiting to happen as who is going to be there to judge the weight of the replacement fixture down the line.

So was this EC giving me BS about some exeption. By the way this was done in a 6 story Hotel.

 

[chris kennedy]

This I have now corrected, one of those things you forget about. But why did the luminaire come down?

The people that live upstairs are huge fans of Pogo Sticks?

 

[1793]

The people that live upstairs are huge fans of Pogo Sticks?

Should add that this luminaire is on the 2nd floor of a two story SFD.
After a few more posts I will give my thoughts.

 

[electricalperson]

the customer is a very lonely lady and she messes around with the light to call you back so she has someone to talk too. thats my guess or somebody is screwing with it and cant figure out how to put it back together

 

[electricmanscott]

Very suspicious. The box screw holes were probably stripped out or you used the crapola screws that came with the fixture.

 

[1793]

OK my thoughts:

luminaire has the silver foil in the lamp compartment and the supplied insulation on top side.

I think that the heat from the two bulbs, 60w each, caused the plastic box to either soften or expand causing the screws to come loose.

When I return the box has cooled and the screws are tight.

I did replace the old plastic box with a new metal box.

 

[hillbilly1]

The boss's best friend called me out to fix a light that fell in his house, found 100 watt bulbs in a fixture that called for 60 watt max. Had to replace the box because it had melted.

 

[Ebow]

I agree with the heat scenario. The bulbs are heating up the screws which in turn heat up the threaded part of the plastic box causing the weight of the fixture to pull the screws out. #6's would pull out with just a little vibration as they barely secure the fixture as it is.
So I guess I am going for heat by bulbs and vibration by A/C or other source.

Gene
_____________________________________
Remember - Speed Kills and its not always you.

 

[mxslick]

Yep, the heat from the bulbs would be my choice, I have that same luminare in my living room. It is secured to a metal box and hasn't fallen yet, even during some good earthquakes.

 

[jaylectricity]

When forced to hang fixtures and/or smoke detectors from plastic wall boxes used on a ceiling, I usually force an 8/32 into there. Don't know if it helps, but that's what I do.