I am currently replacing an old fluorescent light fixture with three
recessed lights.

A 20 amp fuse (not breaker) was used for the circuit that contained
this fluorescent light and the over-the-range microwave. The
previous-to-previous owners did much of the work in the house
themselves and usually did a poor job at it (for example, after taking
down some drywall we discovered rot everywhere that lead to finding out
the the overflow pipe that connects to the bath tub was never fitted
with the rubber gasket so there was an inch gap that lead to the tub
leaking whenever a bath was taken - they instead CAULKED the overflow
outlet in the tub).

In this situation the main feed from the fuse goes somewhere (sorry I
can't be more helpful); an outlet box that is about 1/2' from the
ceiling (weird I know) has a 3-wire cord (red, black, and white)
coming from the ceiling and contained a splice to a 2-wire cord (black
and white) that connected to the fluorescent light (with electrical
tape). I ripped all the tape apart and removed the outlet box as we'll
be permanently removing and filling in the hole where that was -
unfortunately I didn't look to closely how the wires were connected.
From this they must have had two of the three from the 3-wire cord
spliced together with one from the 2-wire cord. I removed the 2-wire
cord and all that is left is the 3-wire cord that I hope to use for the
three recessed lights.

I took a multimeter to the three wires and this is the result:

SWITCH OFF
black & red = 26V
black & white = 120V
red & white = 18V

SWITCH ON
black & red = 0V
black & white = 120V
red & white = 120V

A single switch controls the light fixture but the microwave is always
on. Unfortunately I cannot see behind walls to well and I am not sure
how everything is connected, but if persuaded I'll delve deeper.

Any ideas on what is going on? Is the black and white used together
for the microwave but is for some reason still fed up to the light
fixture? What do I splice together out of the three to form one hot
and one neutral?

I'd also like to add that the swithch is a two-way switch and not a
three-way switch.

After looking further, I'm guessing the black is the always hot and was
used to supply a steady current to the outlet near the ceiling. This
outlet will no longer be there - can I properly terminate the black
wire (how) and then just use the red and white wire to power the
recessed lighting?

On 26 Jan 2007 08:06:15 -0800, wrote:

After looking further, I'm guessing the black is the always hot and was
used to supply a steady current to the outlet near the ceiling. This
outlet will no longer be there - can I properly terminate the black
wire (how) and then just use the red and white wire to power the
recessed lighting?

I hope you're not trying to do all of this in your head.

Make a diagram/drawing of all the wires, etc, including wire color of
course.

After the first diagram is made, redo it on another sheet of paper,
trying to make it logical rather than just visual. That is, if two
wires go to the same place, group them together in the second drawing
even if they weren't when you look at the actual wires. Make the
drawing so it helps you understand what is going on, piece by piece.

On Jan 26, 1:06 pm, wrote:
After looking further, I'm guessing the black is the always hot and was
used to supply a steady current to the outlet near the ceiling. This
outlet will no longer be there - can I properly terminate the black
wire (how) and then just use the red and white wire to power the
recessed lighting?
..
Sounds like you are 'on the right track'.
White should be /usually is neutral all the way back to the
fuse/circuit beaker panel. Neutrals are not switched. But see note 2
about 'white wires'.
Black is usually (although us amateurs can be capable of all kinds of
miswiring!) the live lead from the breaker panel.
The red sounds like it is the 'switched live' for the light fixture.
Two notes:
1) Fluorescent fixtures should be and work better when grounded.
2) While in your case the red seems to be the switched live (and this
is not to confuse you) occasionally one can encounter a white wire
that is a 'switched live'.
For example: In this jurisdiction the inspectors prefer that one use
red/black to wall switches; the black takes the 'live' lead to the wall
switch and the red comes from the other side of the switch to the light
fixture/s. But sometimes the electrician didn't have red/black and used
white/black, in which case the white 'switched live' is supposed to be
marked in some way (I sometimes use red nail polish or red tape) but
often is not.

SWITCH OFF
black & red = 26V
black & white = 120V
red & white = 18V

SWITCH ON
black & red = 0V
black & white = 120V
red & white = 120V

BTW some of those readings are probably meaningless and are the result
of the high sensitivity of many multimeters to even small 'induced'
voltages. It's better to use a light bulb/test lamp. For example the 26
volts could just be voltage picked by one wire running adajacent to
another wire (capacitve coupling etc.) to a live wire for suitable
distance.
the fact that the red to black drops to zero (i.e. both wires joined
together when the switch is 'on') seems to prove that.
Als the fact that you get 120 volts on the red wire when the swich is
on also seems to prove that red IS the switched live for your new (non
fluorescent, rereading the OP).
A final question; where is the ground (bare coper or green or
green/yellow) for any metal joining boxes and the new light fixtures?

mm, thanks for the insights but I definitely understand what is going
on (and have it written down anyways).

terry, thanks very much for the reply an yours is more of what I am
looking for. The red is definitely the switched wire, I just need to
know how to properly terminate a single wire (the black) as I will no
longer have the outlet there. I don't want to just put a nut on it -
what is the proper way to terminate a single wire? I'm almost thinking
that is why they put the outlet there in the first place - to terminate
the black wire - as this outlet/light fixture is in the middle of the
circuit and comes from the microwave. The outlet was in such an
illogical place (1/2 near the ceiling!?) that it just really makes me
think that's what they did. I also agree that there should have been a
ground wire for the flourescent light - I installed a new flourescent
light about 12' away from this one that I took down and there was a
ground wire available there...

To add, there is no ground wire on this circuit (unless it stopped at
the microwave).

On Jan 26, 12:46 pm, wrote:
mm, thanks for the insights but I definitely understand what is going
on (and have it written down anyways).

....
... The red is definitely the switched wire, I just need to
know how to properly terminate a single wire (the black) as I will no
longer have the outlet there. I don't want to just put a nut on it -
what is the proper way to terminate a single wire?

If you're not using it, just put a wire nut on it and go on. I'd tape
it for a little added comfort, but it really doesn't do anything the
nut didn't/won't do other than add a little extra to keep it in place.
But, if you use the proper size, it'll be tight, anyway.

The "better way" would be to go back to the feed junction and
disconnect it from the feed there. If there is no future need for it,
it could then be cut off flush at each end. Failing that, the best is
to cap it where the present box/junction is so it is accessible for
future.

Whatever this box is presently, even if you use it no longer for any
purpose other than the junction, it must not be covered over by a wall
finish of some sort (drywall, paneling, etc.) but must remain
accessible.

I'm almost thinking
that is why they put the outlet there in the first place - to terminate
the black wire - as this outlet/light fixture is in the middle of the
circuit and comes from the microwave. The outlet was in such an
illogical place (1/2 near the ceiling!?) that it just really makes me
think that's what they did. I also agree that there should have been a
ground wire for the flourescent light - I installed a new flourescent
light about 12' away from this one that I took down and there was a
ground wire available there...

Thanks dpb,

I will just find a proper fitting nut and put that on. I already
removed the box as each recessed light already has it's own box for
housing the splices. Thanks again!