I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!

I think 30v is more than induced curent, I have no idea on a fix but
also check your ground connection to see if current is being wasted to
ground, be carefull the ground could also be hot.

blueman wrote:
I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!

Yes.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

"blueman" wrote in message
...
I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!

You fail to tell where you were working. If it was in your home then you
definitely have some wiring problems. Neutral grounded at than the service
comes to mind.

finding the problem you can try turning off circuits one at a time until the
problem goes away. Then a physical inspection of every box on both circuits
may lead you to a solution

If your at work then who knows. I have seen over 30 v when low voltage
conductors were run in the same conduit as medium voltage conductors. Took
us for ever to find it. I never believed anyone would be that stupid to do
what we found.

blueman wrote:
I was working last night on an electrical circuit that was shut off
at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!

Depends what you measured the 30 Volts with.

The modern digital electronic meters are very high impeadance and can
easily pick up 30 volts from induced voltage as you call it.

A neon test light is also pretty sensitve to induced voltage.

Use an older mechanical volt meter (Simpson 260) or make a test lamp
with a night light bulb.

Mark

On Sun, 13 Mar 2005 09:51:17 GMT, blueman wrote:

I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!


IHMO:

Good question! I've run into this alot, and at the power plant I
worked at, when you opened a breaker our electrictions would verify no
induced voltage. We had lots of high amps cables running side by
side. Many times we were required to put in grounding straps/bars to
cancel out the induced voltage.

Now as for 30v's that is kinda high, but around the definition of
low-voltage(24v) of the NEC, I would verify your volt meter is working
correctly, and check for any potential voltage leakage into the dead
circuit.

Fill us in, on what you found.


later,

tom @ www.MedicalJobList.com

blueman wrote:
I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!

SQLit did bring up a good point. A floating neutral could be a
possibility. Try putting a small load on the circuit and that 30V should
drop to almost zero. It it holds at about 30, then you have a potentially
dangerous wiring problem. However your measurement of 0.7 ma would tend to
rule the neutral problem out.


--
Joseph Meehan

26 + 6 = 1 It's Irish Math

blueman wrote:
I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!


Measuring 30 volts from hot to ground with a high impedance voltmeter
can easily be caused by capacitive coupling to that that wire from
another wire in close proximity carrying full voltage. It's a common
question posed here. It could also occur if the breaker had popped under
overload many times and had a very high resistance leakage path inside
it through deposited vaporized contact material.

But, if you really measured 30 volts from neutral to ground (and didn't
intend to say that the measurement was from hot to ground.) then
there's something seriously wrong because the neutral should be at
ground potential, and there's no way that 700 microamps of capacitive
coupling or leakage is going to create 30 volts between two wires which
are connected together.

Better measure again to be sure, and if you still get 30 volts between
neutral and ground, my guess is that the ground lead ISN'T really
grounded and you're seeing an induced voltage on it too, relative to
neutral. THAT could be sinister.

Let us know what you find,

Jeff
--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"

In article LvYYd.215960$0u.189579@fed1read04, "SQLit" wrote:

"blueman" wrote in message
...
I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!

You fail to tell where you were working. If it was in your home then you
definitely have some wiring problems. Neutral grounded at than the service
comes to mind.

Nonsense. He's probably using a digital multimeter, which is exquisitely
sensitive to very low amperage induced currents. If he uses an analog
multimeter, the "problem" will very likely disappear. There is no reason to
suspect wiring problems of any sort unless these readings are seen with an
analog meter as well.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

blueman wrote:

I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?


Plug in a common household lamp to the dead circuit. Make sure its on.
Now take your meter reading when its under a load. If your still getting
voltage you DO have a problem. My guess is you will show close to zero
once you take the measurement with a load connected to it.

Bob

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
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"Doug Miller" wrote in message
...
In article LvYYd.215960$0u.189579@fed1read04, "SQLit"
wrote:

"blueman" wrote in message
...
I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!

You fail to tell where you were working. If it was in your home then you
definitely have some wiring problems. Neutral grounded at than the service
comes to mind.

Nonsense. He's probably using a digital multimeter, which is exquisitely
sensitive to very low amperage induced currents. If he uses an analog
multimeter, the "problem" will very likely disappear. There is no reason to
suspect wiring problems of any sort unless these readings are seen with an
analog meter as well.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

This is Turtle.

He did state that his compact flourescent light would cause it to light up
dimly. Mill-Voltage does not light up flourescent lites to light up. I thought
that at the first but the flourescent lite took that ideal out.

TURTLE

Doug Miller wrote:

In article LvYYd.215960$0u.189579@fed1read04, "SQLit" wrote:

"blueman" wrote in message
...

I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!

You fail to tell where you were working. If it was in your home then you
definitely have some wiring problems. Neutral grounded at than the service
comes to mind.


Nonsense. He's probably using a digital multimeter, which is exquisitely
sensitive to very low amperage induced currents. If he uses an analog
multimeter, the "problem" will very likely disappear. There is no reason to
suspect wiring problems of any sort unless these readings are seen with an
analog meter as well.

You weren't bothered at all by his saying he measured 30 volts between
neutral and ground?

If you weren't, then please riddle me this Doug. Why would ANY kind of
voltmeter, digital or otherwise, indicate that much voltage between
neutral and ground (That's what the OP stated.) unless there was a
serious defect in the home's wiring.

Jeff


--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?


--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"

m Ransley wrote:

I think 30v is more than induced curent...

It's voltage, not current, and easy to see on an open circuit next to a
powered conductor... 120 V across 10 pF/foot over 100', ie 1000 pF, ie
1/(2Pi60C) = 2.6 meg in series with a 10 meg meter would make it show 95 V.

You seem very determined to show your ignorance :-)

Nick

(Doug Miller) writes:

In article LvYYd.215960$0u.189579@fed1read04, "SQLit" wrote:

"blueman" wrote in message
...
I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!

You fail to tell where you were working. If it was in your home then you
definitely have some wiring problems. Neutral grounded at than the service
comes to mind.

Nonsense. He's probably using a digital multimeter, which is exquisitely
sensitive to very low amperage induced currents. If he uses an analog
multimeter, the "problem" will very likely disappear. There is no reason to
suspect wiring problems of any sort unless these readings are seen with an
analog meter as well.

Yes, I am using a digital voltmeter and when I "short" the conductors
to ground the total currrent is just 0.75mA which was what made me
think induced current. However, this being electrical, I wanted to
check to make sure I wasn't missing something.

The Real Tom Tom @ www.WorkAtHomePlans.com writes:
On Sun, 13 Mar 2005 09:51:17 GMT, blueman wrote:

I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!


IHMO:

Good question! I've run into this alot, and at the power plant I
worked at, when you opened a breaker our electrictions would verify no
induced voltage. We had lots of high amps cables running side by
side. Many times we were required to put in grounding straps/bars to
cancel out the induced voltage.

Now as for 30v's that is kinda high, but around the definition of
low-voltage(24v) of the NEC, I would verify your volt meter is working
correctly, and check for any potential voltage leakage into the dead
circuit.

Fill us in, on what you found.

I verified this with 2 different digital voltmeters, albeit none of
them very professional ones.

Jeff Wisnia writes:

blueman wrote:
I was working last night on an electrical circuit that was shut off at
the breaker.
Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.
Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?
Thanks!


Measuring 30 volts from hot to ground with a high impedance voltmeter
can easily be caused by capacitive coupling to that that wire from
another wire in close proximity carrying full voltage. It's a common
question posed here. It could also occur if the breaker had popped
under overload many times and had a very high resistance leakage path
inside it through deposited vaporized contact material.

But, if you really measured 30 volts from neutral to ground (and
didn't intend to say that the measurement was from hot to ground.)
then there's something seriously wrong because the neutral should be
at ground potential, and there's no way that 700 microamps of
capacitive coupling or leakage is going to create 30 volts between two
wires which are connected together.

Better measure again to be sure, and if you still get 30 volts between
neutral and ground, my guess is that the ground lead ISN'T really
grounded and you're seeing an induced voltage on it too, relative to
neutral. THAT could be sinister.

Let us know what you find,


Good point! I did indeed find 30 volt both hot-to-ground and
neutral-to-ground.

However, I believe I can explain the neutral-to-ground voltage very
simply. The reason I was opening up the junction boxes in the basement
and checking voltages was that I was having some wacky behavior with
most of the circuit out but a few of the compact flourescents dimly
lit. It turns out that one of the neutrals had slipped out of the wire
nut. This could explain the induced current in both the neutral and
the hot since with the breaker off they were both effectively
"floating".

Let me know though if you think I am missing something.

Thanks.

In article , Jeff Wisnia wrote:

You weren't bothered at all by his saying he measured 30 volts between
neutral and ground?

Not if he measured it with a digital meter, no.

If you weren't, then please riddle me this Doug. Why would ANY kind of
voltmeter, digital or otherwise, indicate that much voltage between
neutral and ground (That's what the OP stated.) unless there was a
serious defect in the home's wiring.

Digital meters can read voltages at *extremely* low currents. *Any* device
that produces a magnetic field can induce an electrical current on wires that
pass near it. Unexpected currents of less than line voltage, when read by
digital meters, should be verified with an analog meter before leaping to the
conclusion that there is "a serious defect in the home's wiring."

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

He said it lit a compact flourescent bulb also. That does not sound
like a meter problem or induced voltage. The floating ground sounds
more likely.

Stretch

"stretch" wrote in message
oups.com...
He said it lit a compact flourescent bulb also. That does not sound
like a meter problem or induced voltage. The floating ground sounds
more likely.

Stretch

It takes about 70 volts to set off the neon bulb testers. It also takes
almost no current for them. Induced voltage will very easy light them up.
I use the testers almost every day at work in a large plant. I have seen
the tester light up, read about 100 volts on a Fluke digital meter and
about 20 volts on the good old Simpson 260 analog meter . While I don't
think it will really hirt you, I can tell you that it will make you hirt
yourself, especially if you are hot and sweaty.

If a nutral is loose and feeding back on it, you can get almost the full
voltage and almost the full current of the circuit it is connected to.

blueman wrote:

Jeff Wisnia writes:


blueman wrote:

I was working last night on an electrical circuit that was shut off at
the breaker.
Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.
Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?
Thanks!


Measuring 30 volts from hot to ground with a high impedance voltmeter
can easily be caused by capacitive coupling to that that wire from
another wire in close proximity carrying full voltage. It's a common
question posed here. It could also occur if the breaker had popped
under overload many times and had a very high resistance leakage path
inside it through deposited vaporized contact material.

But, if you really measured 30 volts from neutral to ground (and
didn't intend to say that the measurement was from hot to ground.)
then there's something seriously wrong because the neutral should be
at ground potential, and there's no way that 700 microamps of
capacitive coupling or leakage is going to create 30 volts between two
wires which are connected together.

Better measure again to be sure, and if you still get 30 volts between
neutral and ground, my guess is that the ground lead ISN'T really
grounded and you're seeing an induced voltage on it too, relative to
neutral. THAT could be sinister.

Let us know what you find,



Good point! I did indeed find 30 volt both hot-to-ground and
neutral-to-ground.

However, I believe I can explain the neutral-to-ground voltage very
simply. The reason I was opening up the junction boxes in the basement
and checking voltages was that I was having some wacky behavior with
most of the circuit out but a few of the compact flourescents dimly
lit. It turns out that one of the neutrals had slipped out of the wire
nut. This could explain the induced current in both the neutral and
the hot since with the breaker off they were both effectively
"floating".

Let me know though if you think I am missing something.

Thanks.

Roger that, I think you're on track now. If you reconnected that neutral
wire nut and left the breaker open I'd bet dollars to donuts that you'd
still measure "something", but now less than 30 volts, with that meter
between hot and neutral or hot and ground, but nada between neutral and
ground. (Because the capacitance between the hot and neutral in that run
would form the lower leg of a capacitive voltage divider and shunt some
of that stray current to ground.)

Glad you got it fixed though!

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"

"blueman" wrote in message
...
The Real Tom Tom @ www.WorkAtHomePlans.com writes:
On Sun, 13 Mar 2005 09:51:17 GMT, blueman wrote:

I was working last night on an electrical circuit that was shut off at
the breaker.

Nevertheless, the voltage from neutral to ground and from hot to
ground both measured about 30V. This was enough to cause my voltage
probe to buzz and to even cause a compact flourescent to light
dimly. The current across the circuit however measure just 0.7 mA.

Am I correct in assuming that this is probably just induced voltage
from neighboring wires that run alongside it or is there potentially
something more serious and sinister going on?

Thanks!


IHMO:

Good question! I've run into this alot, and at the power plant I
worked at, when you opened a breaker our electrictions would verify no
induced voltage. We had lots of high amps cables running side by
side. Many times we were required to put in grounding straps/bars to
cancel out the induced voltage.

Now as for 30v's that is kinda high, but around the definition of
low-voltage(24v) of the NEC, I would verify your volt meter is working
correctly, and check for any potential voltage leakage into the dead
circuit.

Fill us in, on what you found.

I verified this with 2 different digital voltmeters, albeit none of
them very professional ones.

Serious this time........take your reading and then take several more
readings, turning on and off some different lights, 110v breakers etc.......

If your measured voltage goes up to near 220v in some instances and then in
other instances down to near or at zero volts then you have a floating
neutral and you really should have someone with experience trace it down and
fix it for you.

Usually its just the main neutral lug screw in the service has come a bit
loose and needs tightened--generally it will be discolored and will have
kinduva darkish 'staining' to it...

BUT the problem could also be in the meter panel or even at the utility co.
transformer.....

Best to use an analog meter for this--( in case this isn't clear to you as
of yet ), these are typically the older meters, or in any case ( generally )
they are meters that have an actual needle rather than having an lcd
display.

--

SVL

Doug Miller wrote:

In article , Jeff Wisnia wrote:


You weren't bothered at all by his saying he measured 30 volts between
neutral and ground?


Not if he measured it with a digital meter, no.


If you weren't, then please riddle me this Doug. Why would ANY kind of
voltmeter, digital or otherwise, indicate that much voltage between
neutral and ground (That's what the OP stated.) unless there was a
serious defect in the home's wiring.


Digital meters can read voltages at *extremely* low currents. *Any* device
that produces a magnetic field can induce an electrical current on wires that
pass near it. Unexpected currents of less than line voltage, when read by
digital meters, should be verified with an analog meter before leaping to the
conclusion that there is "a serious defect in the home's wiring."



No question that magnetic fields can induce voltages Doug, but they are
unlikely to be anywhere near as large as 30 volts in house wiring
because the outgoing and return current carrying conductors are so
physically close to each other that their magnetic fields cancel almost
completely and don't leave much of a net ac magnetic field to induce a
voltage in another nearby conductor. And, I would expect that since the
ground lead is also in close proximity to the hot and neutral leads in
typical house wiring that magnetic field would induce a near equal
voltage in it too, bucking out the voltages induced in the other two
wires, leaving little voltage to measure between them.

It's genberally capacitive coupling which causes those "phantom low
current voltages" on disconnected conductors in houses.

Things can be different in industrial applications where currents can be
much higher and the wire runs a lot longer. For example, running a three
phase circuit between two boxes in three separate pieces of metal
conduit instead of a single larger conduit because a hack installer
didn't have any large enough pipe with him (and didn't know any better)
might not seem dangerous at first thought. But, as soon as some
significant currents are put through those conductors they induce
currents in the three conduits, which, since they're electrically
onnected together at both ends by the walls of the boxes, act like a
shorted 3 phase transformer secondary. The three conduits can get hot
and often will start arcing where they join onto the boxes.

At any event, the OP found the problem, an open connection in the
neutral lead at a wire nut. The degree of "seriousness" of that defect
in his house wiring is debatable.

Peace,

Jeff


Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"

"PrecisionMachinisT" writes:

Serious this time........take your reading and then take several more
readings, turning on and off some different lights, 110v breakers etc.......

If your measured voltage goes up to near 220v in some instances and then in
other instances down to near or at zero volts then you have a floating
neutral and you really should have someone with experience trace it down and
fix it for you.

Usually its just the main neutral lug screw in the service has come a bit
loose and needs tightened--generally it will be discolored and will have
kinduva darkish 'staining' to it...

BUT the problem could also be in the meter panel or even at the utility co.
transformer.....

Best to use an analog meter for this--( in case this isn't clear to you as
of yet ), these are typically the older meters, or in any case ( generally )
they are meters that have an actual needle rather than having an lcd
display.

SVL

Thanks -- as pointed out in another post, I ended up tracing problem
back to loose wire nut (that was just installed by a licensed
electrician no less).

I hope that this explains everything, including the dimly lit compact
flourescent, so that there are no other problems I need to look for
now that everything seems to be fixed and working properly.

Interesting about the Analog meter -- my parents were going through
some of my childhood stuff and found my circa 1974 20+ range Archer
multimeter (there were no digital ones then). I would have thrown it
out other than for sentimental reasons, though it sounds now like I
should keep it!

"blueman" wrote in message
...
"PrecisionMachinisT" writes:

Serious this time........take your reading and then take several more
readings, turning on and off some different lights, 110v breakers
etc.......

If your measured voltage goes up to near 220v in some instances and then
in
other instances down to near or at zero volts then you have a floating
neutral and you really should have someone with experience trace it down
and
fix it for you.

Usually its just the main neutral lug screw in the service has come a
bit
loose and needs tightened--generally it will be discolored and will have
kinduva darkish 'staining' to it...

BUT the problem could also be in the meter panel or even at the utility
co.
transformer.....

Best to use an analog meter for this--( in case this isn't clear to you
as
of yet ), these are typically the older meters, or in any case (
generally )
they are meters that have an actual needle rather than having an lcd
display.

SVL

Thanks -- as pointed out in another post, I ended up tracing problem
back to loose wire nut (that was just installed by a licensed
electrician no less).

I hope that this explains everything, including the dimly lit compact
flourescent, so that there are no other problems I need to look for
now that everything seems to be fixed and working properly.

Interesting about the Analog meter -- my parents were going through
some of my childhood stuff and found my circa 1974 20+ range Archer
multimeter (there were no digital ones then). I would have thrown it
out other than for sentimental reasons, though it sounds now like I
should keep it!

Suggest do the testing as I described anyways just to be certain--though I
havent followed this thread completely and so its unclear to me what you did
find as the cause.

But yes I do prefer to use the older meters. I dont much care for having to
de-cipher phantom readings, or having deal with a scale value that won't
settle in to some reading that actually makes sense...with an older meter,
the needle generally swings into position reliably and repeatably.

--

SVL

According to Doug Miller :
In article , Jeff Wisnia wrote:

You weren't bothered at all by his saying he measured 30 volts between
neutral and ground?

Not if he measured it with a digital meter, no.

_Even_ with a digital meter. Hint: neutral and ground are _supposed_ to be
shorted together at the panel. Unless there's a break in the neutral or ground,
even a digital meter shouldn't see that much difference between ground and
neutral.

Showing 30V hot to ground or neutral, when the breaker is off, is where the
impedance of the meter matters.

[Worst case difference between neutral and ground, assuming the circuit
is in operation is about 1.5% (allowable voltage drop at full current
thru the neutral).]

The OP's measurement of .7ma is also too high for impedance effects. It'd
be a few microamps or less.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

wrote:
m Ransley wrote:


I think 30v is more than induced curent...


It's voltage, not current, and easy to see on an open circuit next to a
powered conductor... 120 V across 10 pF/foot over 100', ie 1000 pF, ie
1/(2Pi60C) = 2.6 meg in series with a 10 meg meter would make it show 95 V.

You seem very determined to show your ignorance :-)

Nick


At last! Somebody else who really understands what's happening in such
cases.


Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"

On 13 Mar 2005 14:02:55 -0500, wrote:

m Ransley wrote:

I think 30v is more than induced curent...

It's voltage, not current, and easy to see on an open circuit next to a
powered conductor... 120 V across 10 pF/foot over 100', ie 1000 pF, ie
1/(2Pi60C) = 2.6 meg in series with a 10 meg meter would make it show 95 V.

You seem very determined to show your ignorance :-)

Nick


Redo your problem Nick, your problem solving for was for a single
conductor, and measuring voltage end to end. Not for two(or more)
conductors running side by side, and measuring voltage at one end.
The voltage induced in one conductor, would be exacly the same as the
induced in the others, therefe for no potential would exist between
the conductors(as in OP's story) where the voltage should be sensed,
between the conductors and an immediate grounding source(not the ECG,
since that is one of the parallel conductors).

I'll give you an A for effort, Faraday would be proud. :-P

BTW, the NEC covers taking steps to minimize induced voltages and
inductive heating, even for common fokes, it gives enough information
about how running conductors close together will reduce/elminate it.
Just that I see often that digital meters show voltage, on dead legs,
and I've chatted with others about how to ensure you have no juice
left. One smart chap said, cind the ECG and Neutral are bonded, why
not bond the ungrounded(hot) conductors, we cam up with an idea that
you can bond all three with a shorted out three prong plug. Now
voltage should be ZERO, but we figured come time to close the breaker,
we would forget it in place, and melt it.

later,

tom

The Real Tom wrote:

On 13 Mar 2005 14:02:55 -0500, wrote:


m Ransley wrote:


I think 30v is more than induced curent...

It's voltage, not current, and easy to see on an open circuit next to a
powered conductor... 120 V across 10 pF/foot over 100', ie 1000 pF, ie
1/(2Pi60C) = 2.6 meg in series with a 10 meg meter would make it show 95 V.

You seem very determined to show your ignorance :-)

Nick



Redo your problem Nick, your problem solving for was for a single
conductor, and measuring voltage end to end.

Not the way I read it Tom. The voltage measured end to end on that
isolated conductor would be zero.

I believe he was describing a single isolated conductor running near one
with an ac voltage on it. The 95 V he mentioned would be measured
relative to the other side of the ac source swinging that powered
conductor (Which would of course be "neutral" and/or "ground" in a
home.) That voltage would be the same anywhere along its length.

He really should have described the most likely case; that the isolated
conductor in a home wiring system would be a black wire in a length of
Romex and the white wire and ground leads in that Romex would be
connected to the other side of the ac source (ground). So, there would
be a fair amount of capacitance between the isolated conductor and the
two grounded ones in the Romex, probably more than the amount per foot
he estimated for a "nearby" powered conductor. That would create a
capacitive voltage divider, so the voltage measured on the isolated
conductor couldn't possibly reach the 95 V level he mentioned.


Not for two(or more)
conductors running side by side, and measuring voltage at one end.
The voltage induced in one conductor, would be exacly the same as the
induced in the others, therefe for no potential would exist between
the conductors(as in OP's story) where the voltage should be sensed,
between the conductors and an immediate grounding source(not the ECG,
since that is one of the parallel conductors).

I'll give you an A for effort, Faraday would be proud. :-P

BTW, the NEC covers taking steps to minimize induced voltages and
inductive heating, even for common fokes, it gives enough information
about how running conductors close together will reduce/elminate it.

Twisting the conductors really helps with the inductive heating stuff.

Just that I see often that digital meters show voltage, on dead legs,
and I've chatted with others about how to ensure you have no juice
left. One smart chap said, cind the ECG and Neutral are bonded, why
not bond the ungrounded(hot) conductors, we cam up with an idea that
you can bond all three with a shorted out three prong plug. Now
voltage should be ZERO, but we figured come time to close the breaker,
we would forget it in place, and melt it.

later,

tom


Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"