melting plastic boxes

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Howard Burger

Senior Member
labels on the lights' sockets?

labels on the lights' sockets?

OK, I'm being picky. You said the box was labelled for 60W. What if any, do the sticky labels on the sockets inside the light indicate? I've been suprised in the past to find 40W labels on the sockets of what I thought were 60W fixtures.
 

fireryan

Senior Member
Location
Minnesota
OK, I'm being picky. You said the box was labelled for 60W. What if any, do the sticky labels on the sockets inside the light indicate? I've been suprised in the past to find 40W labels on the sockets of what I thought were 60W fixtures.

both say 60w. I got the info on the light:

Made by patriot lighting
model # 351-4210
 

hurk27

Senior Member
Take a look at 314.27 which states that boxes used at luminaire outlets shall be designed for the purpose.

I would argue that the wall boxes you used were not designed for the purpose, as you have found out.

And the exception even spells it out that they can be used for a wall hung fixture only if it weighs 6# or less.

The exception kind of tells the intent of this requirement, so yes the single gang plastic box in a ceiling, is a violation to support a light fixture.
 

Chamuit

Grumpy Old Man
Location
Texas
Occupation
Electrician
As you have suspected, the boxes are wall boxes meant for switches and receptacles, not luminaires. The manufacuter's web site says they are not fire rated.

However....I am suspect that the fixtures may not be manufactured to the UL specs they are sold under. 3 60's is hot, but I have yet to see a fixture designed for 3 60's that would melt a Carlon box of any kind, ceiling or not. The price mentioned for the fixture makes me think they were made in China to sub standard specs and sold for a pittance to the unsuspecting. Combine that with mounting to a box not designed for the application and 'Huston, we've got problems'.

I did this once. Only one fixture, only one s/g box, only once. The little 6/32's gett nice and hot and slide right out. Of course, it didn't help that the lite was on for several hours.
 

growler

Senior Member
Location
Atlanta,GA
assuming your men did not remove the insulation thinking it was part of the packaging, i would guess the fixture may have been rated for 3 25 watt bulbs and mislabled with a sticker saying 3 60 watt bulbs...

Even if they are listed for 3 ea. 60 watt lamps it's more practical to use the CFL type lamps so as not to generate so much heat. When a fixture over heats the lamps don't last very long.

I don't trust those small fixtures with 180 watts of heat.
 

Sparky555

Senior Member
Have never seen or heard of this problem before. We put in some closet lights that are a 12inch light with 3 60w bulbs in them. These lights are mounted to plastic nail on outlet boxes not the round nail on boxes for lights. We come back the next day and the lights and boxes are hanging out of the ceiling because the boxes are melted and distorted enough to come off the nails. The 6/32 screws also loosened because of the heat. Anyone had this problem with these cheap plastic boxes? Could the light be causing this much heat?

Don't ceiling boxes have 8-32 screws?
 

GUNNING

Senior Member
CFL's

CFL's

This sort of thing happened to me twice both for the same reason.
I used a nail on single gang box on a hall light and took out the fiberglass insulation to install, and the next day the light was hanging from the ceiling by the wires with the box melted and the screws pulled out. Solution, leave the fiberglass mating on the fixture.
Second time it was with a fan kit. Got the call that all three fan kits were hanging from the fans by 2 wires. The plastic had melted and the fixture stud let go of the plastic housing on the butt end of the fan motor. The fan manufacuter forgot to put in the fiberglass matting on the light fixture and added the sticker that said "NO MORE THAN 60 WATTS TOTAL LAMP WATTAGE", for real. It was a manufacturers defect and they relabled the fixture reducing the wattage and inserting the fiberglass matting. It was right after California stopped using incandescent lamps. Somehow the fixture made it to Florida

Best guess here is the yellow fiberglass matting was missing on this fixture despite what the help says. I would be safe and replace the box with something metal OR use CFL's.
 

nizak

Senior Member
There is definetley something wrong, period! In 20 years I have never seen a pvc box melt from the proper installation of a fixture with 60W lamps. To my knowledge the same material is used to produce a single gang nail on box or a round nail on ceiling box.Any type of heat that is substantial enough to melt a box is a real serious problem.There must be more to the story than is being told.
 

fireryan

Senior Member
Location
Minnesota
There is definetley something wrong, period! In 20 years I have never seen a pvc box melt from the proper installation of a fixture with 60W lamps. To my knowledge the same material is used to produce a single gang nail on box or a round nail on ceiling box.Any type of heat that is substantial enough to melt a box is a real serious problem.There must be more to the story than is being told.

Nothing more to the story. It is what it is. Insulation on top of fixture was NEVER removed and is all intact as should be. Takes 3 60W bulbs as stated on sockets and on the box. Gonna change the boxes out to metal pan boxes to take care of the problem of the lights melting boxes. Might tell homeowner to maybe get a different light or maybe change to cfl as discussed. It just makes me nervous these lights are causing this much heat. There is 3 more throughout the house but they are all mounted on metal boxes.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Well, the drywall screws holding the fixture bar to the blue PVC switch box didn't pull out. :roll: And, from the photo, that looks to be an insulated ceiling.

That's a style of luminaire that holds heat. No two ways about it.

Back through the Eighties, we were told, by various inspectors, not to use round blue and yellow PVC nail on ceiling boxes, boxes that were listed for luminaire support, because of this same problem.
 
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Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
Don't let these pics get out to one of the other forums. They don't like Carlon boxes anyway!:grin:

Looks like if there was that much heat those 18 or 22 AWG wires would have been damaged too.
 

fireryan

Senior Member
Location
Minnesota
Well, the drywall screws holding the fixture bar to the blue PVC switch box didn't pull out. :roll: And, from the photo, that looks to be an insulated ceiling.

That's a style of luminaire that holds heat. No two ways about it.

Back through the Eighties, we were told, by various inspectors, not to use round blue and yellow PVC nail on ceiling boxes, boxes that were listed for luminaire support, because of this same problem.

Yeah those screws are what the construction guy put in after the light fell down
 
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