I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the light
fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I have
a non contact volt sensor but it was not working and also I was tempted to
give the finger test but I'm getting old and my heart may not take the kick.
I guess I should have referenced the polarities to a cold water pipe. What
would you do?

I wouldn't worry about it and go home and get a good sleep.


"# Fred #" wrote in message
...
I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the
light fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I
have a non contact volt sensor but it was not working and also I was
tempted to give the finger test but I'm getting old and my heart may not
take the kick. I guess I should have referenced the polarities to a cold
water pipe. What would you do?

The finger test won't help, you need to use the two arm test from the wires
to the nearest grounded thing, but I'd recommend something other than your
body parts



"# Fred #" wrote in message
...
I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the
light fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I
have a non contact volt sensor but it was not working and also I was
tempted to give the finger test but I'm getting old and my heart may not
take the kick. I guess I should have referenced the polarities to a cold
water pipe. What would you do?

# Fred # wrote:

I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the light
fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I have
a non contact volt sensor but it was not working and also I was tempted to
give the finger test but I'm getting old and my heart may not take the kick.
I guess I should have referenced the polarities to a cold water pipe. What
would you do?



If I had a long enough piece of wire handy I'd put the smallest bulb
handy in the fixtur, connect its black wire to one of the two power
wires and connect my piece of wire to the white fixture lead, then touch
its other end to a water pipe and have someone switch on the power.

If the bulb lit I'd know the fixture's black wire was on the correct of
power lead. If it didn't light I'd repeat the test with the black
fixture lead connected to the other power wire.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

On Tue, 12 Dec 2006 12:50:16 -0800, "# Fred #"
wrote:

I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the light
fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I have
a non contact volt sensor but it was not working and also I was tempted to
give the finger test but I'm getting old and my heart may not take the kick.
I guess I should have referenced the polarities to a cold water pipe. What
would you do?

Do you own a circut test lamp?

"# Fred #" wrote in message
...
I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the
light fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I
have a non contact volt sensor but it was not working and also I was
tempted to give the finger test but I'm getting old and my heart may not
take the kick. I guess I should have referenced the polarities to a cold
water pipe. What would you do?

Neon testers are really, really inexpensive.

As others said use a neon bulb tester. Touch one lead to your hand and the
other to the circuit. If it is the hot lead the tester will dimly light. I
would still be sure to wear sneakers and not be touching anything grounded.
Try first in a plug.


"# Fred #" wrote in message
...
I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the
light fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I
have a non contact volt sensor but it was not working and also I was
tempted to give the finger test but I'm getting old and my heart may not
take the kick. I guess I should have referenced the polarities to a cold
water pipe. What would you do?

"# Fred #" wrote in message
...
I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the
light
fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I
have
a non contact volt sensor but it was not working and also I was tempted to
give the finger test but I'm getting old and my heart may not take the
kick.
I guess I should have referenced the polarities to a cold water pipe. What
would you do?



I'd run a lead to the nearest water pipe or sink faucet.

"# Fred #" wrote in message
...
I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the
light fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I
have a non contact volt sensor but it was not working and also I was
tempted to give the finger test but I'm getting old and my heart may not
take the kick. I guess I should have referenced the polarities to a cold
water pipe. What would you do?


If this is the biggest problem you ever encounter working on older homes you
have gotten off real easy.

As Hotrod said, " go home and sleep well".

Colbyt

On Tue, 12 Dec 2006 16:36:35 -0500, "Charles Schuler"
wrote:


"# Fred #" wrote in message
...
I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the
light fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I
have a non contact volt sensor but it was not working and also I was
tempted to give the finger test but I'm getting old and my heart may not
take the kick. I guess I should have referenced the polarities to a cold
water pipe. What would you do?

Neon testers are really, really inexpensive.


And not only that, but if you touch one lead to a hot wire and grab
the other lead (of the neon tester) with your fingers, the neon will
show a slight glow. It wont do that on the neutral. And you wont get
a shock doing this. I do it all the time. To be totally honest, I
really never understood why it lights when touched, but it works.

Go out and spend the 2 bucks for the neon tester and save lots of time
and shocks too. Touching hot wires is not a good idea at anytime,
even though I do see professional electricians do it.

I know what you are dealing with. On the old K+T the wires were often
all the same color black, or if one was white, its too dirty now.
Those cloth wires had a tar or wax like substance in the coating which
seemed to discolor them over time. Once you ID them, put some white
electrical tape on the neutrals.

wrote:
esters are really, really inexpensive.



And not only that, but if you touch one lead to a hot wire and grab
the other lead (of the neon tester) with your fingers, the neon will
show a slight glow. It wont do that on the neutral. And you wont get
a shock doing this. I do it all the time. To be totally honest, I
really never understood why it lights when touched, but it works.


"It woiks" because your body has "free space capacitance"* which can
accumulate a charge, like it does when you scuff your shoes on a carpet,
and will get discharged when you "spark" to ground (or to another
person's capacitance, sharing your charge with them). The value of your
body capacitance varies from about 100 to 300 picofarads, depending on
whether you are skinny or fat.

AC line voltage connected to one side of the the neon tester drives a
minute current (less than a milliamp) in and out of your body's
capacitance, and that current is enough to make the tester's bulb glow.

* The free space capacitance of an object is the sum mutual capacity of
it to all the conducting objects of the universe. (Wow!)

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

spake thus:

On Tue, 12 Dec 2006 16:36:35 -0500, "Charles Schuler"
wrote:

"# Fred #" wrote in message
...

I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the
light fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I
have a non contact volt sensor but it was not working and also I was
tempted to give the finger test but I'm getting old and my heart may not
take the kick. I guess I should have referenced the polarities to a cold
water pipe. What would you do?

Neon testers are really, really inexpensive.

And not only that, but if you touch one lead to a hot wire and grab
the other lead (of the neon tester) with your fingers, the neon will
show a slight glow. It wont do that on the neutral. And you wont get
a shock doing this. I do it all the time. To be totally honest, I
really never understood why it lights when touched, but it works.

Well, obviously it lights because some current is flowing through it
(and your body). Apparently little enough to not give you a buzz.

Thanks but no thanks. The other day I was installing a circuit in a
flooded basement, and I was paranoid to even touch boxes and cables with
the circuits de-energized. (You know, wet shoes and all.) I prefer other
ways of donating my body to science.


--
Just as McDonald's is where you go when you're hungry but don't really
care about the quality of your food, Wikipedia is where you go when
you're curious but don't really care about the quality of your knowledge.

- Matthew White's WikiWatch (http://users.erols.com/mwhite28/wikiwoo.htm)

On Wed, 13 Dec 2006 08:47:12 -0600, wrote:

On Tue, 12 Dec 2006 16:36:35 -0500, "Charles Schuler"
wrote:


"# Fred #" wrote in message
...
I just helped someone to replace an overhead light fixture in an old house
with existing K&T wiring without wire termination ID. I referenced the
light fixture terminal polarities to the nearest K&T ungrounded outlet but
realized if that outlet is wired wrong so will my light installation. I
have a non contact volt sensor but it was not working and also I was
tempted to give the finger test but I'm getting old and my heart may not
take the kick. I guess I should have referenced the polarities to a cold
water pipe. What would you do?

Neon testers are really, really inexpensive.


And not only that, but if you touch one lead to a hot wire and grab
the other lead (of the neon tester) with your fingers, the neon will
show a slight glow. It wont do that on the neutral. And you wont get
a shock doing this. I do it all the time. To be totally honest, I
really never understood why it lights when touched, but it works.


Neon bulbs require at least about 90V to light, but draw very little
current. Maybe that helps.

Go out and spend the 2 bucks for the neon tester and save lots of time
and shocks too. Touching hot wires is not a good idea at anytime,
even though I do see professional electricians do it.

I know what you are dealing with. On the old K+T the wires were often
all the same color black, or if one was white, its too dirty now.
Those cloth wires had a tar or wax like substance in the coating which
seemed to discolor them over time. Once you ID them, put some white
electrical tape on the neutrals.
--
12 days until the winter solstice celebration

Mark Lloyd
http://notstupid.laughingsquid.com

"How could you ask be to believe in God when there's
absolutely no evidence that I can see?" -- Jodie Foster

David Nebenzahl wrote:
Thanks but no thanks. The other day I was installing a circuit in a
flooded basement, and I was paranoid to even touch boxes and cables with
the circuits de-energized. (You know, wet shoes and all.) I prefer other
ways of donating my body to science.

For years I've had a small screwdriver with a neon bulb in a translucent
handle, and a little metal contact on top. To test for AC voltage, you
hold your finger on the contact and shove the blade of the screwdriver
into the outlet or onto the conductor being tested. The only time I
came even close to sensing anything at all was when I used it at its
maximum rated voltage, 600V. At that I might not have noticed the
sensation had I not been aware it might happen.

--
Asking Iran and Syria to help us succeed in Iraq is like your local fire
department asking a couple of arsonists to help put out the fire.
-- Joe Lieberman