"Rebel1" wrote in message
...
On 10/19/2011 9:27 AM, Rebel1 wrote:
On 10/18/2011 9:01 PM, Rebel1 wrote:
This apartment has strange problems. Incandescent bulbs burn out too
fast, usually when a switch is turned on. I monitored line voltage with
a plug-in meter that displays voltages in the range of 90 to 130. The
needle stays pointing in the green zone (110 to 125 volts). I don't live
there, but I left the meter there and the renter says it stays in the
green zone.

Aside from that problem, the kitchen has a ceiling fan with three light
bulbs (standard base). The bulb in one position burns out, again when
power is switched on, much more often than the other two.

I've tried using bulbs rated at 130V. Seem to give better life, but
there is still a definite problem that I can't blame on simple high
voltage. There is no flicker that could indicate that the bulb isn't
fully screwed into the socket.

This is an "illegal" apartment, which means that there can be many code
violations.

Thanks for you suggestions/comments.

R1

Up until 9 years ago, the entire apartment was a single room in a large
building with 3 other rental units in it. The owner divided this room
into an apartment for a fourth tenant, my friend.

It turns out that the bulbs in the bathroom, bedroom, and closet do NOT
burn out prematurely. The problem is confined to the kitchen, dining
nook and hallway. As far as my friend knows, the bulbs in any of the
other rental units do not burn out prematurely.

My friend's apartment is on the second floor, along with one other
rental unit. A circuit breaker panel in the common hallway controls
power to the two rentals. I now suspect that one of the breakers feeds
the circuits that have the short-lived bulbs, even though I can't figure
how a defective breaker could do this. I asked her to turn off each
breaker and map out which breakers control the various outlets and
lights in the apartment. I may not hear from her for a few days.

R1

It turns out that the kitchen fan was part of the original house, built in
1976. At that time, it was probably just a bedroom fan, which 9 years ago
became subdivided to create a new apartment. None of the circuit breakers
that control the rest of the apartment affect the kitchen fan/light. That
breaker is probably in the garage. So it is possible that aluminum wiring
was used in the original building. I'll check when I examine the breakers
in the garage.

At this point,the problems a
1) just a single bulb in the kitchen fan burns out prematurely, which is
located on old wiring that does NOT cause problems in the other
second-floor apartment, and
2) some of the bulbs on the new wiring burn out prematurely. I may take my
o-silly-scope there to look for spikes over the weekend. I'll report my
findings.

R1

Earlier, there was a post that mentioned vibration. My experience is that
bulb vibration failures are more common than high voltage or spike problems.
That particularly applies here because the main problem bulb is in a fan.

One solution is to use a "vibration service" bulb which has extra filament
supports and thicker filament wire. Sometimes such bulbs are packaged as
ceiling fan bulbs. Noise, which causes vibration, can be the culprit too.
Traffic and aircraft noise can be picked up by the walls and ceilings of a
building and cause them to vibrate which shakes the filament. New bulbs are
not particularly sensitive; but, as the bulb burns, the filament becomes
thinner and more brittle, so the bulb burns out early.

TKM