Jim - It sounds like a circuit diagram is necessary to find out what
wire is doing what.
Some ideas to help (remembering that electricity is dangerous and you
need to use appropriate caution):
- Make a diagram of the outlet including each connection so you can
always put it back together the old way
- Turn off the circuit and disconnect each wire. Verify each wire has
no power. A non-contact voltage tester is helpful. Put a wire nut on
each bare end for safety.
- Turn the power back on and see which wire is the hot supply. If that
is the two wire cable, you found your neutral, which should be the other
wire in the pair. If it is the three wire cable (black or red), that
white wire is probably your neutral and the other wire (red or black)
may be a second hot wire on another circuit.
- You already figured out some of the outlets after this on in the
circuit. I'd go to the next closest outlet and make the same diagram in
that outlet. Hopefully, it will make more sense with a single pair in
and out. With the power off and verified with a voltage tester, put a
continuity checker on the wire pair in one outlet box and touch the
wires in the second box to verify you have the wire pair identified.
This process should help further figure out the wiring in the home.
Other things that may help:
- disconnected wires, such as when the circuit breaker is off or when
the neutral is disconnected my indicate an odd voltage with a digital
volt meter. Put a load on the wires and the voltage will go to near
zero. I used a lamp socket with a light bulb.
- if you have metal boxes, they may be wired with a ground wire
independent of the electrical supply wires. This was the case in my my
first and my current houses.
- three conductor wire may have been used to run two circuits with a
single wire pair. Two hots share a neutral. I don't think this is code
anymore and don't recommend it. Part of the theory is that if they are
out a phase (different lines of the 220 supply), the single neutral can
handle it.
- The red may be a switched circuit, where perhaps there was a wall
switch that controlled the outlet. If you have any wall switches, check
them and see if they come into play in your circuit diagram. At some
point, an overhead light may have been connected to the wall switch and
the old wires to the outlet were just left behind.
- Some electricians follow a pattern on supply into the top of the box
and next outlet out the bottom of the box (I may have that backwards)
for wall outlets, so if you are mapping multiple outlets, that may make
things easier.
Good luck with the project. Taking the time to do the full circuit
diagram in my 1950 built house was critical to understanding the
problems I was having and figuring out a way to fix issues, such as
every outlet but one in the original portion of the house including the
refrigerator on the same circuit. I ended up rewiring all those outlets
into four circuits and ended the common computer lockups or beeping UPS
warnings.
Brian
On 3/24/2013 8:50 AM, Jim and Kathy wrote:
> I have a very strange electrical problem at my vacation home and am hoping
> someone here has an idea of what could be going on.
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