Can light thoughts

[Barony]

Installed some can lights in our addition. I have 3 lights on 1 600 watt dimmer switch, and 5 lights on another 600 watt switch. I have been having problems with 2 lights on the 5 light chain, that after 45 minutes of being on, suddenly shut off for 15 minutes and then come back on. It's happened almost every night, and not the same lights. Any thoughts? Change to a 1000 watt switch? This is a dedicated circuit for these lights, so there is only 1 other draw and it is a switched outside light that is never on. Thanks.

[RoosterR]

Do you have the right bulbs in them? Usually that is a sign that the light is getting to hot do to wrong bulbs.

[JohnMickish]

It's the thermal switch in those two lights. Do you have the right lamp/trim combo? The trim will list the type/wattage of lamp that it can work with. If they don't match up it can cause heat to build up and trigger the thermal device. Either that or the thermal device is bad.

What brand fixtures did you get? Commercial Electric, Feit, Juno, Lutron?

[Barony]

I was a two boxes of 4 lights from a box store. I checked the side of the box and have the right bulbs in there, so that isn't the problem. I do not relish the thought of having to crawl into the attic to replace the cans if that is the issue. Brand new cans too.

[LightningBG]

Shouldn't be a problem with the switch if only some of them are going off. Its gotta be heat.

You mentioned the attic. Are they surrounded in insulation and are they rated to be surrounded in insulation? If not you're going to have to replace them or build boxes around them to keep the insulation away.

[JohnMickish]

Good point. Do your lights have an IC rating? Anyways, the beauty of the can lights it everything can be reached thru the hole in the ceiling. It's designed that way. I said it can be reached, I didn't say it was easy or fun.

[CAMAN]

IMO, you should have fully sealed, moisture barriered and insulated boxes built around all can lights in an attic. You can wrap them in insulation, but you still get airflow through that and a TON of heat loss.

[Barony]

The units are Quantums units. I was using a dimmer switch and thought it might be that, so I replaced the switch w/ a regular switch to see if it was that, and it's not. The units are IC, but I did not put boxes over them, just blown insulation. Looks like that could be the next step (boxes).

[JohnMickish]

With IC cans you don't have to build boxes, and most of them have a nice silicone sealing surface to help prevent the heat loss. IC means they are rated for direct contact with insulation material.

[Barony]

This is one of the many reasons why I drink. Arg.

[JohnMickish]

This is one of the many reasons why I drink. Arg.

Funny, but these "simple" projects can get very frustrating if things don't go as planned, especially if the wife starts to nag.

[reddog]

ICAT cans are insulation rated and air tight.

IC housings are far from airtight, but considerably better than their predecessor.

It could be a faulty heat sensor in the housing also.

What wattage bulb do you have in them?

[Barony]

Had 75 watt bulbs and switched to 65 watt bulbs. That seems to have fixed the problem. The lights have been on since 7 and all is well. Thanks for all the help guys. Easy solution in hind sight. The 75 watt bulbs got too hot I guess and kicked out the sensor.

[BobT]

Were those cans rated for 75w? Sounds like a lot.

[spearchucker]

Did you use a regular 75W bulb? I have never seen the BR30 75W lights.

[Barony]

I did use regular 75 watt bulbs, thus the problem. Things are good now though.

[JohnMickish]

I did use regular 75 watt bulbs, thus the problem. Things are good now though.

You can't do that. That little decal inside the light that says what lamps go with what trims is there for a reason. If the thermal device hadn't tripped out there is a chance the thing would have gotten so hot it would have started on fire. There is a reason they put those stickers in there.