John and all,

Thanks for the advice. I probably could have provided more detail, for
instance, the circuit breaker box is completely new one year ago, by a very
competent electrician (not me). The wiring to the old stairway lights is BX
conduit with old copper. I have had problems in other fixtures with the
older wiring in this place, so I should have comsidered the potential (no
pun intended) of a floating neutral or loose connection. I'll go through
each of these next to check them out.

I'm pretty sure this sensor is not the two stage you suggest. The reason it
goes on after being powered off and on is this is how it is tested. It
remains lit for 2 mins. then goes out. Afterward, it is dependent on
darkness and movement. At any rate, I will remove it again when I check the
old wiring in the stairwell.

The stairwell sockets are normal sockets which I can place ordinary bulbs. I
have the compact fluorescents in them except for the one incandescent I
tried to check the socket. That's how I discovered the "half lit" bulb.

Thanks again,

Greg

"John Grabowski" wrote in message
news
Greg, This is difficult to diagnose over the internet with the small
amount
of information given, but here are my thoughts:

I think that you may actually have two separate problems. First is that
you
wrongly wired the motion sensor. I'm not sure if you are aware of it or
not, but there are certain motion sensors that are made to light up the
bulbs at half brightness when it gets dark and when someone crosses the
path
the bulbs will light fully.

You provided a clue in your statement:
"I test the motion sensor by turning off the breaker, then turn it on. The
single spot lights up brightly, but the stairwell lights are out (except
for
the dim incandescent). Then after 2 mins. the spot goes out and so does
the
dim bulb!"
Sometimes a motion sensor will react that way when power is turned off and
then back on.

Look for some other problem with the fluorescent lights in the stairway.
Maybe you have a bad ballast or a loose connection. The fact that the
fluorescent problem surfaced weeks later indicates that it may not be
connected to the motion sensor. Open up the fluorescent lights and see if
you have 120 volts. Try connecting a pigtail socket and bulb to the feed
and see if it lights normally.


John Grabowski
http://www.mrelectrician.tv




"gccch" wrote in message
news:y_b9d.3465$4b.2077@trndny09...
Hello all,

This is a long explanation, but basically I am looking for what could
cause
a light bulb to light up only dimly. Could it be a short to GND or some
other leakage?

Here's the situation.
I have a three floor apt. building with a common panel feeding a lighted
fire escape. They are not switched, always on for safety. On this same
circuit, before reaching the stairwell is a single light in the
basement.
No
problems with this light. There are 2 other leads I have not yet
verified
where they go (either disconnected or feeding something I am unaware
of).
On
the outside of the stairwell is a spot light with a motion sensor to go
on
at night when you go around back. The problems started with the
spotlights
remaining on all the time. Not knowing the age of the sensor I replaced
it,
wired as directed on the package. Since it was summer, I don't know if
it
ever worked properly. I was unable to test it fully. Later, I noticed
the
spots were very dimly lit. The stairwell lights were full power and lit
properly. I removed one spot and the other would light fully. I left it
that
way, but still unsure if the motion sensor is working properly. Again
weeks
later, now the lights are out in the stairway. I've been using
fluorescent
bulbs. The bulbs light up in other sockets on another circuit. I
replaced
one with a regular incandescent and it is barely lit.

I test the motion sensor by turning off the breaker, then turn it on.
The
single spot lights up brightly, but the stairwell lights are out (except
for
the dim incandescent). Then after 2 mins. the spot goes out and so does
the
dim bulb!

The stairwell lights are NOT switched by the sensor. I have removed the
sensor completely, and these bulbs are still not lighting up.

How can the sensor affect the stairwell lights? Why would they not get
enough power to turn on completely?

Obviously, I am not an electrician, but I do have a clue how this stuff
works. I'm about ready to re-wire the darn stairwell.

Any advice?

Greg