I don't understand your description, but it's far from meeting code so you
really do have something to be looked into. I still think you have an open
ckt somewhere, either hot or neutral, depending on where you're seeing the
40Vac measurement. If one shows the 40V and not the other, that's going to
be the one that is open ckted. Remember though if it's a switched outlet,
the switch must be ON for the ac measurement.
Another way to check the wires is to ohm them out. Kill the main power
breakers and open the relevant breaker. and tie the hot to the neutral at
one end or the other, and measure the ohms of the wires from the other end.
It shouldn't be more than an ohm or two, often closer to a half ohm or so.
Don't forget to disconnect hot from neutral when you're done.
120Vac hot to gnd = OK
0.0V neutral to gnd = OK assuming there IS a gnd wire connected.
120 Vac hot to neutral = OK.
Radio Shack sells handly little testers you just plug in and read the LEDs
for this kind of thing too; handy to have.
Sounds like the vac just tripped whatever had to happen to push the ckt to
an open ckt. Not unusual for loose wires in a fixture/outlet/switch/etc.
They start with a surge that would create an arc if there were a poor
connection and eventually the carbon from the arc would open the ckt.
Happens all the time with loose connections.
Newsgroups are great places to get assistance.
If you have a very low voltage from the hot to neutral and 124 volts form
the hot to ground, I would look for an open neutral. If you cut the breaker
off and check the resistance between the neutral and ground you may find
that open. There should be a very low (almost zero) resistance between the
two. One guess is there are several recepticals on that circuit and atleast
one is between that one and the breaker box. Try finding all of them and
plugging a lamp into both sockets, one at a time. Chances are you will find
power on one socket and not the other. A jumper between the screws can burn
out between the two.
So, going from the GFI outlet closest to the breaker (next room), it
was the only one working. I pulled the receptacle from the next one
and examined it. Loose wire in there with some black from a flash/
burn. I tightened it up, restored power, and everything works. I'm
replacing the receptacle right now (same 20A type).
Thanks for the help everyone.
Glad you found it,
Simple wasn't it ?
I am an electrician at a large plant, but I did not stay at a Holiday Inn.
I had something similar like that happen to me about 15 years ago. It took
out the hot wire instead of the neutral. Vacuum cleaner did that to me
also. Guess that motor starting up draws lots of current and will take out
any marginal receptacle.
As far as the wiring question with the stove, I would not like to guess at
that without seeing it. I don't think you will have any problems with it,
but still do not like the idea of borrowing a ground with a wire of a much
lesser gauge than the main wires. I don't know the code for the grounding,
but bet it would not pass. As mentioned the old 3 wiring should be
grandfathered in and would be ok. Most stoves will use the two 240 volt
wires for the elements and very little current will be on the neutral wire,
just whatever the stove uses for the 120 volts. Probably only the lights
and clock/oven control circuits.
When you replace the receptacle, wire it up using the pigtail
The black from the "supply" and the black to downstream loads should
be wire nutted together along with a short (pigtail) black wire that
supplies the local receptacle.
Do the same with the neutrals.
Wiring up a receptacle in this manner will keep the rest of the
circuit working even if a "local" device fails.
Voltages sound like an open neutral, best covered by RBM. I might test
with something like a light bulb in a pigtail socket. If the neutral was
open just H-G would light up.
Very slight chance a breaker is tripped and has to be turned off hard to
Do you know which breaker is for that receptacle? (H-G voltage should
disappear when turned off.)
Are any other receptacles dead? (Could be where neutral is open, or also
Do you know of other receptacles on that breaker that are working? (They
would also be candidates for where the neutral is open.)
When one wire is close to another AC wire, there is some
power that is transferred by magnetic waves. Your VOM is
probably reading this "ghost voltage". There is probably not
enough amperage to do anything useful. But, your VOM is
On Sat, 6 Mar 2010 12:47:52 -0800 (PST), Mike Reed
If you are seeing an induced voltage, you are probably using a digital
meter, which are high impedeance, mabye 11MegOhms per volt.
You mght want to measure the same place with an analog meter. They are
iirc 20KOhms or maybe 50KOhms per volt, either way must lower, so they
put a load on the voltage that dissipates the 40 volts but very low
maximum current that you may have, and the voltage will read
correctly, probalby very near zero.
Analog meters are those with needles that move.
Except for FET-VOMs which are analog and use a needle, but have very
high impedance. I'm not recommending one of those, but I think there
have been none of those for sale for 25 years. And they probably say
FET-VOM on them. At the bottom of the needle area, it says the
impedance of the meter in ohms per volt.
For most things, I still like digital meters, which are auto-polarity
for one thing.
I agree with the induced voltage concept. I have encountered this
many times. Put a power strip onto your outlet, then put your
voltmeter into the power strip. If you get 40 V, then plug some
appliance into another receptacle in the power strip. Your voltage
will go to 0. The most likely thing to be wrong here is that your GFI
failed (a common occurrence). You can pull the GFI out of the box and
measure the voltage going to the GFI. If you have proper voltage
entering the GFI, then your GFI is dead. If you don't have voltage,
then your breaker is probably bad. Either is fairly easy to replace.
Start at the source and work your way back.
Remove the breaker panel and measure the voltage right on the breaker
when it's on. If you don't get 110/120 volts there, the breaker is
probably faulty. Replace it before moving on.
If you know the order the outlets are wired in, work your way along the
circuit, testing at each outlet until you reach the end. Most likely you
will read full voltage till you get past a certain outlet. Go back to
the previous outlet, pull it out, and inspect it (with the power off, of
course). I'm betting a connection has arced, come loose, or otherwise
failed in one of the outlets.
If you don't know the wiring order, pull every outlet out one by one and
inspect the wiring. If it were me, I would go ahead and replace every
outlet in the room. Unless it's a very large room or multiple rooms are
on the circuit, it shouldn't cost more than $20 to replace all the
outlets. Cheap peace of mind, and you'll know you have good outlets for
the coming years.
Also, if the outlets are wired "daisy chain" (incoming cable is wired to
one side of the outlet, outgoing cable is wired to the other side), I
recommend rewiring so the cables connect directly with a short pigtail
running to the outlet in that box. That way, power runs directly from one
box to the other, and not through an electrical outlet.
Oh, if any outlets have the spring loaded "stab" connections on the back,
replace the outlet and make the connection on the screw terminals.
Finally, inspect the wiring where it enters and exits the box. I've never
had a problem with plastic boxes, but metal boxes can cut into the cable
or can be damaged if the clamp was overtightened.
I would suggest two things. You have a bad neutral. Very bad
and very dangerous, or you are using a sensitive digital meter that is
picking up ghost voltage. As soon as you put a load on that kind of
circuit, it will dorp to zero volts again. The first one you call the
pro in. It might be in your home or it might be a problem out side.
If it is the second issue, it is nothing of substance.
What you have is an open circuit in the Hot lead somewhere back to the
breaker box, almost certain.
The 40 Vac will often be a simply "phantom volage" caused by all kinds of
things in the air and the high impedance of the meter can see it. Plug a
nightlight or anything with a bulb into the ckt and the voltage will almost
surely go away. It's sort of like static voltage, but comes from a
different source by way of an analogy. 40Vac is a rather typical voltage
for such things.
If the 40V ac does not go away when a bulb is plugged in, there there is
a serious wiring problem somewhere but 99.999% of the time it's going to be
an open ckt in the wiring. Probably at an outlet or a switch.
In fact, even properly wired ckts will often show the 40Vac if there is a
switch to the outlet and it's turned off; same situation an an open ckt.
But when the switch goes on, it should jump to a solid 120Vac level,
whatever voltage is normal for your area.
It's may or may not be dangerous; it depends on where and how the open ckt
has occurred. You should get it checked out soon, or open that breaker until
someone does get there to look at it.
This business of false or phantom voltage readings has been mentioned
many, many times on this and other news groups in the past.
Even the cheapest of today's digital multimeters can pick up induced
voltages from a 'dead' or disconnected wire which runs nearby other
wires etc. A reading of 40 volts is probably meaningless. Another
meter might give 21 volts; again meaningless! And even radio/wireless
waves, which are very low strength higher frequency AC emanations can
be picked up by any length of wire acting as an antenna/aerial!
As variuos posters have mentioned 'plug something 'real' such as a
lamp, into the GFI and if it does not light up something is open
somwhere between the output prong contacts of that outlet and circuit
breaker feeding that circuit. Try the preceding outlet on that circuit
to see if it it has power!
If all is correct back to the circuit breaker there should be full
115/120 volts on the live lead (usually black*) lead into the 'input'
side of the GFI. However the neutral (usually white*) could be open.
*In North American practice.
Finally the GFI may be faulty. Pertinent ...................
Question; are any outlets 'upstream' of the GFI working OK?
Question; is the GFI the last outlet on that circuit 'run', that would
mean there are no further outlets downstream of it!
Question; or is the GFI the first outlet on that circuit run; if so
and it is faulty then all other outlets downstream of it may also
have no voltage.
It is also very difficult explaining when one has no idea of the
electrical knowledge of the enquirer! Something that, makes complete
sense to anyone knowledgeable, may be difficult/dangerous to someone
Oops. Should hav read the following
Unsafe by my reckoning, double ovens hooked to what gauge wiring??????
"using the oven's ground for the neutral ..............." yikes!!!!
More than hokey by sound of it. And don't think an insurance company
would be very sympathetic if something did happen!
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