Bad Neutral? Recessed Light Thermal Switch Activates
#1

Hi all, I just installed a series of Juno 5 in IC recessed lights. They are rated for 75 watt incandescent but I´m using 60 watts for the test. All are equally insulated and equally lamped. I ran 14 guage wire and the total load does not exceed 80% of the 15 amp line. There are two branch curcuits that go to non-recessed lights that do not have problems. The last light in a series of 8 (the main branch) will go out due to the thermal switch activating after about 1 hour on high. I replaced the fixture and even re-ran new wire between the problematic and previous fixture. I´m wondering if I might have a bad neutral. If so, could the bad neutral be on a switched branch circuit, or must it be on the main line between where the branch occurs and the last light? The problem occurs whether the branch switches are on or not. Am I on the right track in troubleshooting this, or is my electrical inexperience showing? Thanks for any help or advice. It´s holding up the sheetrock and I really do appreciate it!

#4
I think trinitro is on to something. Flood type bulbs project the light (and therefore some of the heat) downward, while standard incandescents project it upwards almost as much as downwards. Recessed fixtures are more likely to trap heat. Try spot lamps of the same wattage and see what happens. If you are already using spot lamps, and the "clixoff" (thremal switch) continues to open, I agree to swap out that fixture for a new one.
I don't see how the neutral could affect the thermal switch.
Juice
I don't see how the neutral could affect the thermal switch.
Juice
#5
Thanks for the replies. I´ve already tried replacing the fixture, but unless I had 2 units in a row with a bad thermal switches, I don´t think that´s the problem. The fixtures are open without trim/baffles and without spots/floods (I´m using regular bubs temporarily). That may be the problem, although all the other cans are open, with idententical 60 watt bulbs and only the last position in the series has the recurring problem. The fixtures are also rated for PAR-30 Halogen bulbs which produce a lot more heat, so if the 60 watt regulars are a problem, then Halogens will definitely not work, baffles or not. I may be off the deep end, but if the hot side is carrying the full amperage/voltage, but the neutral cannot handle the same, could there be a heating-element effect with too much resistence and wouldnt this occur at the last fixture? Just a desperate theory!
#6
It wouldn't be unheard of to get a bad batch of fixtures with defective thermals in them. Might try asking some questions of the store where they were bought. Maybe you aren't the only one. Try replacing the fixture again just for giggles.
#8
no, unfortunately I don´t have the number for the trim I´m planning on installing. Right now there is no trim. The guy who sold them to me said that there should be no problems with running them without trim during the remodel. He says that contractors do it all the time.
#9
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Guess that shoots down my theory.
You did re-check the wire connections at all of the fixtures?
Why don't you disconnect the other fixtures and just have the problem one hooked to power to see if it'll work. If it doesn't work, take it back to the store and get a new one.
You did re-check the wire connections at all of the fixtures?
Why don't you disconnect the other fixtures and just have the problem one hooked to power to see if it'll work. If it doesn't work, take it back to the store and get a new one.
#11
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""but if the hot side is carrying the full amperage/voltage, but the neutral cannot handle the same, could there be a heating-element effect with too much resistence and wouldnt this occur at the last fixture?""
It doesn't work like this. Whatever current flows through the hot conductor will flow through the neutral. If the neeutral would have a bad connection that spot will overheat.
I still think it's a bulb problem. Perhaps there is a difference in airflow or free space with that location. I've never had good luck using regular bulbs with recessed lights. They all shut off after a while. Halogen bulbs may generate more heat, but they "project" most of that heat downward.
It doesn't work like this. Whatever current flows through the hot conductor will flow through the neutral. If the neeutral would have a bad connection that spot will overheat.
I still think it's a bulb problem. Perhaps there is a difference in airflow or free space with that location. I've never had good luck using regular bulbs with recessed lights. They all shut off after a while. Halogen bulbs may generate more heat, but they "project" most of that heat downward.