Hi Everyone,

We replaced most of our incandescent light bulbs with compact
fluorescent bulbs about a year and a half ago (it was before the NA
blackout last year). The bulbs are holding up fine, except in the
bathrooms, and I am wondering what could be the reason.

The fixtures have five (three in the powder room) bulbs in parallel, and
we use the 7W (40W equivalent) bulbs. We have lost about five bulbs
since last year, all of them the 7W variety, four in the five-light
fixture, one in the three-light fixture. I do not think they lasted more
than 100 hours max, and they are guaranteed for 5000 hours. The same
size bulbs in table lights so far are ok.

I am wondering what could be the reason for such a high rate of failure?
Is it possible that the powering up event of three or five lights in
parallel produces more transients, or something like that?
There is also more moisture for short periods of time in the bathroom,
but not in the powder room.
I have double checked the wiring of the fixtures, they are wired
correctly, for live and neutral, with the ground attached.

They are also selling similar bulbs, specifically for vanities, about
2.5 times the cost of the regular ones. They only seem to have the
balloon shaped and sized differently around the spiral. I would be
surprised if there were any other differences between them.

Any comment on the above?

--
Peter E. Orban
National Research Council of Canada
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