My kitchen lights (60w bulb) blow out at least monthly, but more like
twice a month. What can be the cause of this? This if the only room in
the house with this issue.
There area number of possible issues.
Is there any vibration sources near them? (exhaust fan, equipment above
them etc.)
Are they enclosed where heat may be a factor?
Is there any chance of moisture?
Do you have any areas of your home where the lights tend to brighten or
dim at times? Especially if they do so in response to some other electrical
even like the furnace or washer or frig starting or stopping?
Are those the only lights burning out early?
If other lights are burning out early around your home, you could have
what is called a floating neutral. It is the result of a poor connection of
the "white" neutral wire somewhere. The result is some outlets and lights
may receive more than the expected voltage and others less. The amount may
change as different loads are added or subtracted.
This can be dangerous. It it exist it can cause a fire and damage
appliances.
Compact fluorescents can fare even worse in recessed ceiling fixtures.
Their output of convected and convected heat is not reduced as much as
many would expect, since they produce little infrared. A 42 watt spiral
compact fluorescent can produce slightly more convected/conducted heat
than a 60 watt incandescent.
Add to this the fact that screw-base compact fluorescents cannot
withstand high temperatures as well as incandescents because heat is bad
for the built-in ballasts in screw-base CFLs.
In recessed ceiling fixtures, if you use screw-base CFLs it is better
to:
1) Use CFLs rated for such use, such as Philips SLS of wattages 15, 20,
and non-dimmable 23 watts
2) In general, use lower wattage. Odds are fair if you don't exceed 23
watts, better if you don't exceed 18 watts.
- Don Klipstein ( snipped-for-privacy@misty.com)
Note: not all recessed lights are rated to be used with insulation close
to them. They will overheat and create both a fire hazard and reduced lamp
life.
The bulb. The socket looks fine, although, not high-end. And there are
two sockets on the same line - both eat up lightbulbs pretty
frequently. No moisture or obstructions that I can see.
If you use those lights a lot, it could be high line voltage. Mine is 130
volts and that is damned hard on incandescent bulbs.
Have you checked your line voltage?
That's the first thing I would recommend. Head down to Radio Shack and
get a cheap digital voltmeter for $10. Then just set it for AC voltage,
remove the light bulb, and touch one lead to the inside threaded part of
the socket and the other lead to the center of the socket. If you're
reading much over 120 V, that could explain the short lifespan of the bulbs.
You should still measure the sockets where you say the bulbs last
longer.
Even if your voltage is correct at this location, if it is lower at
other locations, bulbs will last longer there.
No, I don't especially think that is the situation, but when one does
testing, he should test and record everything that could be relevant.
Later on, he can figure out what is important and what isn't.
Although he likely won't figure that out until he figures out the
problem. That's why he needs all this info.
I'll do that. In addition, I'll record the dates of each new bulb and
when it blew. That should give me a true impression of the issue - if
one exists.
Thanks!
Most incandescents do not get major excessive wear from this.
Incandescents do often die on cold starts, but the explanation is
usually mainly that they become unable to survive a cold start a little
before they become unable to survive steady operation.
What usually happens in an aging incandescent is that the filament
develops a thin spot that is also a bit of a hot spot. This weak spot in
the filament is prone to temperature overshoot during a cold start, due to
the resistance of filament material varying directly with temperature and
the thin spot warming up faster.
Protection from temperature overshoot on such a "deadly thin spot"
usually helps little since their running a bit hot even steadily makes
such filament thin spots suffer accelerated aging in a vicious cycle that
accelerates worse than exponentially.
- Don Klipstein ( snipped-for-privacy@misty.com)
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.