Why do our under-cabinet halogen lights repeatedly fail (i.e., entire system stops working)?

Question

We bought a small (3 light) under-counter set that is plugged into an ordinary outlet and installed the set in our kitchen. We love it...but after a time, it just stopped working. My husband replaced it with a whole new set...and now that one has stopped working as well. We bought a meter to test our outlet, but all we could figure out from that is that the outlet is delivering the right amount of voltage. What are we missing?

We've not yet had a chance to try bulb replacement, since both times the whole set has failed (never one light, or two), which leads us to believe it's a "system" failure...

Bruce--we've never had the chance to change the bulbs yet. The bulbs haven't blown--the whole system has failed.

More info for Bruce--after our first installation failed, we threw the whole thing away and bought another one at a different home improvement store, so if we managed to catch a crappy run TWICE under those circumstances, then maybe we ought not even think about replacing the lights...

I just tested the bulbs--all three are good.

Answer 1

It would help if I knew what type of bulb your using; but…Quartz halogen bulbs are designed to operate at extreme temperatures. The most common failure is caused by changing single layer glass bulbs with your bare hands. The oil on the hands {think finger print} causes hot spots and will burn a bulb of that type out in about a month. The easiest way to prevent this is to get a clean pair of socks out of the drawer and put them on your hands like gloves before changing. Good luck…Bruce the electrician...Woops, just caught the part about not having changed bulbs. Did you install them? If not take your meter and do a continuity or Ohms check on the bulbs. If electricity passes through the bulbs they are good, and you probably have a “Monday morning” run of lights. {300 bad sets get out before they are caught} If they don’t pass I’ll stand by my original answer…Bruce

Answer 2

Addition: Ok, I don't know if you are still following this item but I think I may have an answer from another web site. The problem that another individual had suggested that there is a thermal overload switch of some sort built into some of these fixtures. In your case it is possible that this thermal overload switch just went bad and did not work at all, but cut off power to the light. See this link.
http://experts.about.com/q/Electrical-Wiring-Home-1734/Intermittent-light-failure-new.htm


Heat is always the enemy of electrical equipment. If the proper temperature is not maintained, and usually the cooler the better, the electrical component will fail.

There are usually two possible causes of high temperature leading to premature failure:
1) The installation traps heat and the fixture overheats.
2) The design of the equipment provided inadequate cooling and it's going to fail unless you somehow provide an external source of cooling.

This is true on lighting, computer equipment and just about anything electrical. You have to keep it cool.

Sometimes you can burn out motors by supplying them with a low voltage due to a bad connection and voltage drop across the connection, but I don't think this would affect a light fixture.

i don't know how fast these things are burning out, but on a temporary basis you could put a fan on it to see if that extends the life of the bulb. Also, you may be able to get a temperature read using one of those "instant read" thermometers that are used for cooking. You could compare the temp to other fixtures in the house that do not have a failure problem, if you have anything comparable such as recessed lighting fixtures.

A link below verifies the need to maintain proper cooling, and also suggests that bumps of the fixture could cause failure of the element.

Answer 3

Under Cabinet Halogen Lights

Answer 4

I installed such a system in my fathers home several years ago. It had five lights on two separate transformers Recently, I added another light to the system so there are three lights each on the two transformers. This system has never failed.

Are you replacing the wires too, or just the transformers? Could there be a problem with the wires. Perhaps a nail or staple through one. Or a loose wire shorting out inside one light. This seems unlikely because you would not get these symptoms if that is the case.

I disagree that these systems are inherently defective or that it is a heat problem caused by the lights only. A toaster right under the light can cause a lot of heat, but heating the light wouldn't cause this either. Heat on the transformer could cause a problem.

If you are not replacing 100% of the system, including wires, each time, do that.

Answer 5

I'm gonna speculate that perhaps the 3 halogen bulbs are series wired, so when one bulb fails, they all go; like the former xmas tree lights that were series wired. Then the outlet voltage fluctuations along with the heat accumulation and perhaps long usage cycle just make for short lifetimes (Excess vibration of the lamp filaments is not helpful for extending lamp life either. Harrass those salespeople and others who handle your light bulbs roughly.)

Further, I'd mention that tho the halogen lighting might be esthetically more appealing, I'm thinking that it's less efficient. Halogen and typical indandescent bulbs provide light (and heat!); their lumen output is much less per watt of electricity than fluorescents. Even with flourescents there is heat generated from their ballasts, but the overall efficiency of fluorescents over halogens and typical indandescent is significant. (Fluorescents typically last longer too!)

Answer 6

I am familiar with this type of light. They are problematic. You have a low voltage transformer (usually at the top of the cabinet) and 12volt wiring is routed through your cabinets. Did you change the wiring when you changed the rest of it?You should be able to read the transformer to find its rated output, 12vdc 300va.? Using your meter you could test your transformers output voltage, special attention that you do not short the output wires. There may be some kind of thermal protection in the transformer assembly, you may want to read your directions thoroughly or maybe call the tech line. I would suggest changing to a T-5 fluorescent under cabinet fixture, they have a much better track record.

Answer 7

I am so glad to read that someone else is having problems with these kinds of lights. I love them but my bulbs blow out frequently and then I just decided to replace the entire system. (Again. On my second set)

They are fairly inexpensive and so nice and bright for the kitchen I guess I will continue to replace the entire set each time they fail. The heat factor that someone else mentioned makes alot of sense.

Answer 8

A Lot of those type lights have built in switches are you sure you're not just turning them off by accident, Oh If they are Halogen lights DO NOT touch the bulbs when putting them in, the oils off your fingers will make the bulb blow.

Answer 9

I've seen this before and when someone brings this up I try as I might to sidestep it. I believe it's a heat problem. These lights I believe can't take the heat involved in the places there put although they're made for them. It's just something that's a manufacturing nightmare that shouldn't be used.

Answer 10

I have a similar set and never had a problem with them after 2 years even though I use them almost daily.

I'll bet it is the heat factor discussed above since I installed the dimmer/controller remotely and it does not get any heat where it is at.