Hi all. A simple electrical question (I hope).

I have a clamp on amp meter and I'm interested in seeing how much
current
is used at various loads by the feeder line running to my remote
garage.

The feeder is has 2 hots and 1 neutral going to a sub panel that
divides it
into several 110 circuits.

I know that the current on the neutral will be the difference between
the current on
the two hots (less any stray current lost to the grounding rod), but
I'm interested in
knowing the 'total' amps of the 220 circuit.

I'm thinking I could measure the current on one hot, then on the other
hot, and add
the two values together. What I would like to do is install a
permanent meter but
now I'm thinking that I need two, one for each hot. If I try to
measure the current
by passing both hots through the 'clamp', since they are 180 degrees
out of phase,
won't they cancel each other out (and I would end up with the
difference of the
two like on the netural)?

So my long winded question is this - how can I use a single 'clamp-on'
style meter
to measure current on a 220vac circuit?

Thanks.

kpg wrote:
Hi all. A simple electrical question (I hope).

I have a clamp on amp meter and I'm interested in seeing how much
current
is used at various loads by the feeder line running to my remote
garage.

The feeder is has 2 hots and 1 neutral going to a sub panel that
divides it
into several 110 circuits.

I know that the current on the neutral will be the difference between
the current on
the two hots (less any stray current lost to the grounding rod), but
I'm interested in
knowing the 'total' amps of the 220 circuit.

I'm thinking I could measure the current on one hot, then on the other
hot, and add
the two values together. What I would like to do is install a
permanent meter but
now I'm thinking that I need two, one for each hot. If I try to
measure the current
by passing both hots through the 'clamp', since they are 180 degrees
out of phase,
won't they cancel each other out (and I would end up with the
difference of the
two like on the netural)?

So my long winded question is this - how can I use a single 'clamp-on'
style meter
to measure current on a 220vac circuit?

Thanks.

Run one through in the opposite direction.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

CJT wrote:

kpg wrote:

Hi all. A simple electrical question (I hope).

I have a clamp on amp meter and I'm interested in seeing how much
current
is used at various loads by the feeder line running to my remote
garage.

The feeder is has 2 hots and 1 neutral going to a sub panel that
divides it
into several 110 circuits.

I know that the current on the neutral will be the difference between
the current on
the two hots (less any stray current lost to the grounding rod), but
I'm interested in
knowing the 'total' amps of the 220 circuit.

I'm thinking I could measure the current on one hot, then on the other
hot, and add
the two values together. What I would like to do is install a
permanent meter but
now I'm thinking that I need two, one for each hot. If I try to
measure the current
by passing both hots through the 'clamp', since they are 180 degrees
out of phase,
won't they cancel each other out (and I would end up with the
difference of the
two like on the netural)?

So my long winded question is this - how can I use a single 'clamp-on'
style meter
to measure current on a 220vac circuit?

Thanks.

Run one through in the opposite direction.

Oh, and divide by two.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

"kpg" wrote in message
oups.com...
Hi all. A simple electrical question (I hope).

I have a clamp on amp meter and I'm interested in seeing how much
current
is used at various loads by the feeder line running to my remote
garage.

The feeder is has 2 hots and 1 neutral going to a sub panel that
divides it
into several 110 circuits.

I know that the current on the neutral will be the difference between
the current on
the two hots (less any stray current lost to the grounding rod), but
I'm interested in
knowing the 'total' amps of the 220 circuit.

I'm thinking I could measure the current on one hot, then on the other
hot, and add
the two values together. What I would like to do is install a
permanent meter but
now I'm thinking that I need two, one for each hot. If I try to
measure the current
by passing both hots through the 'clamp', since they are 180 degrees
out of phase,
won't they cancel each other out (and I would end up with the
difference of the
two like on the netural)?

So my long winded question is this - how can I use a single 'clamp-on'
style meter
to measure current on a 220vac circuit?

If you created a loop so that you simultaneously measured one hot backwards
and one forwards it ought to work.
(actually I don't know, but it seems like it should)

Why do you want to do this anyhow? The information is pretty useless.

kpg wrote:
Hi all. A simple electrical question (I hope).

I have a clamp on amp meter and I'm interested in seeing how much
current
is used at various loads by the feeder line running to my remote
garage.

The feeder is has 2 hots and 1 neutral going to a sub panel that
divides it
into several 110 circuits.

I know that the current on the neutral will be the difference between
the current on
the two hots (less any stray current lost to the grounding rod),

Actually, no it won't. If you had a pure 240 load the current on the
neutral would be *zero.* Since you have 120VAC branch circuits, some
will have more load than others, and some will be connected to one phase
and some will be connected to the opposite phase. So you will have
*some* current on the neutral, but it should be significantly less than
the current on either of the "hot" wires.

I realize that sounds very, very strange, but google for "Edison
circuit" for an explanation - a feeder to a remote subpanel is
essentially a really big Edison circuit.

but
I'm interested in
knowing the 'total' amps of the 220 circuit.


It's probably slightly unbalanced. Measure one leg, then the other.

I'm thinking I could measure the current on one hot, then on the other
hot, and add
the two values together. What I would like to do is install a
permanent meter but
now I'm thinking that I need two, one for each hot. If I try to
measure the current
by passing both hots through the 'clamp', since they are 180 degrees
out of phase,
won't they cancel each other out (and I would end up with the
difference of the
two like on the netural)?

So my long winded question is this - how can I use a single 'clamp-on'
style meter
to measure current on a 220vac circuit?

Thanks.


Current is current. You measure it directly.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Why do you want to do this anyhow? The information is pretty useless.- Hide quoted text -

Well, I can't argue with you there. For one, I like gadgets. For
another, I have
a 5hp compressor, some computer equipment, a full time window unit,
and
a part time window unit, a bunch of fluorescent lights, occasionally a
hand drill
or table saw.

It all runs on a 30 amp branch circuit and at times the breaker gets
quite
warm to the touch. I thought it would be nice to be able to monitor
the load on the system, i.e., the amps flowing through the feeder
line.

And did I mention I like gadgets?

I'll do some experiments with the one backwards divide by two
method.

On Aug 13, 11:02 pm, kpg wrote:
Why do you want to do this anyhow? The information is pretty useless.- Hide quoted text -

Well, I can't argue with you there. For one, I like gadgets. For
another, I have
a 5hp compressor, some computer equipment, a full time window unit,
and
a part time window unit, a bunch of fluorescent lights, occasionally a
hand drill
or table saw.

It all runs on a 30 amp branch circuit and at times the breaker gets
quite
warm to the touch. I thought it would be nice to be able to monitor
the load on the system, i.e., the amps flowing through the feeder
line.

And did I mention I like gadgets?

I'll do some experiments with the one backwards divide by two
method.

Each item should have a nameplate. The nameplate will give you a rough
estimate of how much everything is using.

Everything you have listed could be single phase, which means that
each item will cause the reading to go up in only one phase of the
circuit. If you do have 240V stuff it will cause both phases to go up
at the same time.

Measure each leg with nothing on and then turn each item on and read
again.

Unless you are planing to upgrading , try not to use the compressor
and the AC unit at the same time.

The breaker is constantly monitoring the use.

Everything you have listed could be single phase, which means that
each item will cause the reading to go up in only one phase of the
circuit. If you do have 240V stuff it will cause both phases to go up
at the same time.

Yes, all of the equipment is single phase, some on one leg, some on
the
other. This is the source of my dilemma. So what I really am asking
is this: I know its meaningful to measure the current on one leg or
the other, but is it meaningful to measure the current on both at the
same time?

Say I was drawing 8 amps on one leg, and 9 on the other. Am I
using 17 amps? That seems right, but does it have any meaning?

The 30 amp breaker is 30 amps per leg - So who cares if they both
add up to, say, 40?

I'm starting to think measuring each leg independently is the
most correct solution.

You need a watt meter to gauge the total used wattage. The 30 amp breaker
getting warm and not tripping may mean a loose connection. Turn of the 30
amp breaker, remove from the panel. Check to be sure the pinch plate isn't
turning color [getting to hot] and the matching breaker connections are good
as well. Check the lugs on the breaker as well.

You might fare better by calling an experience electrician to check it out.

Zyp

"kpg" wrote in message
oups.com...
Everything you have listed could be single phase, which means that
each item will cause the reading to go up in only one phase of the
circuit. If you do have 240V stuff it will cause both phases to go up
at the same time.

Yes, all of the equipment is single phase, some on one leg, some on
the
other. This is the source of my dilemma. So what I really am asking
is this: I know its meaningful to measure the current on one leg or
the other, but is it meaningful to measure the current on both at the
same time?

Say I was drawing 8 amps on one leg, and 9 on the other. Am I
using 17 amps? That seems right, but does it have any meaning?

The 30 amp breaker is 30 amps per leg - So who cares if they both
add up to, say, 40?

I'm starting to think measuring each leg independently is the
most correct solution.

On Mon, 13 Aug 2007 22:59:25 -0400, Nate Nagel
wrote:

kpg wrote:
Hi all. A simple electrical question (I hope).

I have a clamp on amp meter and I'm interested in seeing how much
current
is used at various loads by the feeder line running to my remote
garage.

The feeder is has 2 hots and 1 neutral going to a sub panel that
divides it
into several 110 circuits.

I know that the current on the neutral will be the difference between
the current on
the two hots (less any stray current lost to the grounding rod),

Actually, no it won't. If you had a pure 240 load the current on the
neutral would be *zero.* Since you have 120VAC branch circuits, some
will have more load than others, and some will be connected to one phase
and some will be connected to the opposite phase. So you will have
*some* current on the neutral, but it should be significantly less than
the current on either of the "hot" wires.

Isn't this what he said?

Not counting the part about stray current lost through the grounding
rod, which I don't really understand. It's rare, isn't it, for any
current to go back through the ground or a grounding rod?

I realize that sounds very, very strange, but google for "Edison
circuit" for an explanation - a feeder to a remote subpanel is
essentially a really big Edison circuit.

kpg wrote:
Everything you have listed could be single phase, which means that
each item will cause the reading to go up in only one phase of the
circuit. If you do have 240V stuff it will cause both phases to go up
at the same time.


Yes, all of the equipment is single phase, some on one leg, some on
the
other. This is the source of my dilemma. So what I really am asking
is this: I know its meaningful to measure the current on one leg or
the other, but is it meaningful to measure the current on both at the
same time?

Say I was drawing 8 amps on one leg, and 9 on the other. Am I
using 17 amps? That seems right, but does it have any meaning?

The 30 amp breaker is 30 amps per leg - So who cares if they both
add up to, say, 40?

I'm starting to think measuring each leg independently is the
most correct solution.



Nobody cares if they add up to 40 amps in your hypothetical example...
simplifying a little bit here, but if you have 29 amps on one leg and 11
amps on another, the current on the neutral will actually be 18 amps (it
won't actually in real life, but close enough) if you have 20 and 20, it
will be zero.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

"kpg" wrote in message
oups.com...
Everything you have listed could be single phase, which means that
each item will cause the reading to go up in only one phase of the
circuit. If you do have 240V stuff it will cause both phases to go up
at the same time.

Yes, all of the equipment is single phase, some on one leg, some on
the
other. This is the source of my dilemma. So what I really am asking
is this: I know its meaningful to measure the current on one leg or
the other,


That's how it is done.


but is it meaningful to measure the current on both at the
same time?


You probably won't get a reading.



Say I was drawing 8 amps on one leg, and 9 on the other. Am I
using 17 amps?

Yes.


That seems right, but does it have any meaning?


It means you are drawing 17 amps and the load is almost perfectly balanced.
You can also measure amps on the neutral. I usually check the grounding
electrode conductor also. Once in a while I find current on it and then I
explain to the customer that there may be a problem somewhere.


The 30 amp breaker is 30 amps per leg - So who cares if they both
add up to, say, 40?


If I was concerned about the load, I would care.



I'm starting to think measuring each leg independently is the
most correct solution.

You are correct.

It's rare, isn't it, for any
current to go back through the ground or a grounding rod?

I thought so until I did some research. There are several situations
where
there can be dangerous current in the ground wire at the ground rod.

Obviously, a fault in the neutral will cause current to use the ground
wire as a return path, but also if your neighbor has a fault in his
neutral his current could be returning to the transformer via your
ground
rod.

Moral: before disconnecting the ground wire to service the ground rod
always check for current. Even if the main is off.

Thanks for all the replies.

I don't know if any electrician reading this post
he must be laughing his head of
what is total amps on 220 whatever you are
reading on your amprob dummy
do you have any knowledge in Ohms law.
and neutral at properly design and grounded system
IS carrying current it is not at zero ever unless on your
screwed up system ground is carrying current
which is not suppose to ever.
and if you take 220 then split the phase of the same
source/cable for 110 the neutral will carry double the current
of single hot wire!
Tony
www.cas-environ.com

"kpg" wrote in message
oups.com...
Hi all. A simple electrical question (I hope).

I have a clamp on amp meter and I'm interested in seeing how much
current
is used at various loads by the feeder line running to my remote
garage.

The feeder is has 2 hots and 1 neutral going to a sub panel that
divides it
into several 110 circuits.

I know that the current on the neutral will be the difference between
the current on
the two hots (less any stray current lost to the grounding rod), but
I'm interested in
knowing the 'total' amps of the 220 circuit.

I'm thinking I could measure the current on one hot, then on the other
hot, and add
the two values together. What I would like to do is install a
permanent meter but
now I'm thinking that I need two, one for each hot. If I try to
measure the current
by passing both hots through the 'clamp', since they are 180 degrees
out of phase,
won't they cancel each other out (and I would end up with the
difference of the
two like on the netural)?

So my long winded question is this - how can I use a single 'clamp-on'
style meter
to measure current on a 220vac circuit?

Thanks.

You really should learn some punctuation before you call someone
dummy.


On Aug 14, 8:36 pm, "Tony" wrote:
I don't know if any electrician reading this post
he must be laughing his head of
what is total amps on 220 whatever you are
reading on your amprob dummy
do you have any knowledge in Ohms law.
and neutral at properly design and grounded system
IS carrying current it is not at zero ever unless on your
screwed up system ground is carrying current
which is not suppose to ever.
and if you take 220 then split the phase of the same
source/cable for 110 the neutral will carry double the current
of single hot wire!
Tonywww.cas-environ.com

"kpg" wrote in message

oups.com...



Hi all. A simple electrical question (I hope).

I have a clamp on amp meter and I'm interested in seeing how much
current
is used at various loads by the feeder line running to my remote
garage.

The feeder is has 2 hots and 1 neutral going to a sub panel that
divides it
into several 110 circuits.

I know that the current on the neutral will be the difference between
the current on
the two hots (less any stray current lost to the grounding rod), but
I'm interested in
knowing the 'total' amps of the 220 circuit.

I'm thinking I could measure the current on one hot, then on the other
hot, and add
the two values together. What I would like to do is install a
permanent meter but
now I'm thinking that I need two, one for each hot. If I try to
measure the current
by passing both hots through the 'clamp', since they are 180 degrees
out of phase,
won't they cancel each other out (and I would end up with the
difference of the
two like on the netural)?

So my long winded question is this - how can I use a single 'clamp-on'
style meter
to measure current on a 220vac circuit?

Thanks

"Tony" wrote in news:tUrwi.4051$%55.3250@trnddc04:

I don't know if any electrician reading this post
he must be laughing his head of
what is total amps on 220 whatever you are
reading on your amprob dummy


Well, I'm not an electrician, this is why I asked the
question. Dummy.

do you have any knowledge in Ohms law.

I have an Ohm meter. Does that count?

and neutral at properly design and grounded system
IS carrying current it is not at zero ever unless on your
screwed up system ground is carrying current
which is not suppose to ever.
and if you take 220 then split the phase of the same
source/cable for 110 the neutral will carry double the current
of single hot wire!

Um, the neutral will carry the difference between the two hot
wires. The total current must be the same coming and going
- do you have any knowledge in Kirchhoff's Law?

Tony wrote:

and neutral at properly design and grounded system
IS carrying current it is not at zero ever unless on your
screwed up system ground is carrying current
which is not suppose to ever.

Not true. The two hots in a 240V circuit are 180 degrees out of phase.
Only the difference between the loads on the two sides flows through
the neutral. Thus, if you have equal 120V loads on each side, the
neutral will have zero current flowing in it.

and if you take 220 then split the phase of the same
source/cable for 110 the neutral will carry double the current
of single hot wire!

If the neutral carried double the current it would have to be oversized
compared to the hots. In reality, it is often *undersized*. The only
way this can make sense is if your statement is false.

This is why split-wire (aka "edison") circuits need to have the two hots
on opposite legs. If they were on the same leg the neutral *would*
carry the sum of the two legs, which could cause overheating.

Chris

"kpg*" wrote in message
20...
"Tony" wrote in news:tUrwi.4051$%55.3250@trnddc04:

I don't know if any electrician reading this post
he must be laughing his head of
what is total amps on 220 whatever you are
reading on your amprob dummy


Sorry I did not mean it as it sound


Well, I'm not an electrician, this is why I asked the
question. Dummy.

do you have any knowledge in Ohms law.

I have an Ohm meter. Does that count?

NO I have few of them and I do not see myself an engineer
or expert by any standard and please don't go there
because I am anticipating that would be your next step


and neutral at properly design and grounded system
IS carrying current it is not at zero ever unless on your
screwed up system ground is carrying current
which is not suppose to ever.
and if you take 220 then split the phase of the same
source/cable for 110 the neutral will carry double the current
of single hot wire!

Um, the neutral will carry the difference between the two hot
wires. The total current must be the same coming and going
- do you have any knowledge in Kirchhoff's Law?


It is been so long since I stody the basics of Kirechhoffs Law,
That I would not atempt to go there
Tony

"Chris Friesen" wrote in message
...
Tony wrote:

and neutral at properly design and grounded system
IS carrying current it is not at zero ever unless on your
screwed up system ground is carrying current
which is not suppose to ever.

Not true. The two hots in a 240V circuit are 180 degrees out of phase.
Only the difference between the loads on the two sides flows through the
neutral. Thus, if you have equal 120V loads on each side, the neutral will
have zero current flowing in it.

I would like wet one of hand and put it on the ground
ant other to the neutral to see if is carrying current
in close loop circuit and use something small to close
loop like 100 watt bulb that should do it
yes why don't try that and let us know
because what you saying 0 potential 0 current
that should be perfectly safe


and if you take 220 then split the phase of the same
source/cable for 110 the neutral will carry double the current
of single hot wire!

If the neutral carried double the current it would have to be oversized
compared to the hots. In reality, it is often *undersized*. The only way
this can make sense is if your statement is false.

This is why split-wire (aka "edison") circuits need to have the two hots
on opposite legs. If they were on the same leg the neutral *would* carry
the sum of the two legs, which could cause overheating.

Chris

plonk

"Tony" wrote in message
news:xfHwi.7146$xc5.2631@trnddc06...

"Chris Friesen" wrote in message
...
Tony wrote:

and neutral at properly design and grounded system
IS carrying current it is not at zero ever unless on your
screwed up system ground is carrying current
which is not suppose to ever.

Not true. The two hots in a 240V circuit are 180 degrees out of phase.
Only the difference between the loads on the two sides flows through the
neutral. Thus, if you have equal 120V loads on each side, the neutral
will have zero current flowing in it.

I would like wet one of "YOU" hand put it on the ground
ant other to the neutral to see if is carrying current
in close loop circuit and use something small to close
loop like 100 watt bulb that should do it
yes why don't try that and let us know
because what you saying 0 potential 0 current
that should be perfectly safe


and if you take 220 then split the phase of the same
source/cable for 110 the neutral will carry double the current
of single hot wire!

If the neutral carried double the current it would have to be oversized
compared to the hots. In reality, it is often *undersized*. The only
way this can make sense is if your statement is false.

This is why split-wire (aka "edison") circuits need to have the two hots
on opposite legs. If they were on the same leg the neutral *would* carry
the sum of the two legs, which could cause overheating.

Chris

According to Tony :

"Tony" wrote in message
news:xfHwi.7146$xc5.2631@trnddc06...

"Chris Friesen" wrote in message
...
Tony wrote:

and neutral at properly design and grounded system
IS carrying current it is not at zero ever unless on your
screwed up system ground is carrying current
which is not suppose to ever.

Not true. The two hots in a 240V circuit are 180 degrees out of phase.
Only the difference between the loads on the two sides flows through the
neutral. Thus, if you have equal 120V loads on each side, the neutral
will have zero current flowing in it.

I would like wet one of "YOU" hand put it on the ground
ant other to the neutral to see if is carrying current
in close loop circuit and use something small to close
loop like 100 watt bulb that should do it
yes why don't try that and let us know
because what you saying 0 potential 0 current
that should be perfectly safe

Even after spelling and gramatical corrections, that's linguistically and
technically wrong, not to mention just plain silly.

Even if the neutral was carrying current, you're not going to get a shock
between the neutral and ground because the voltage difference between the
neutral and ground is at most a volt or two[+]. This is true even in a 120V
circuit pulling 15A.

Remember, the neutral and ground are connected together in the panel.
They're never going to be more than a volt or two different. Unless
something goes very wrong.

The neutral in a 3 wire 240V/120V circuit only carries the difference
current between the two hots. If it wasn't and currents added on the
neutral, then 3 wire 240V/120V circuits would be illegal. I assure you,
they're not. In fact, up until a few years ago, they were _mandatory_
in the Canadian electrical code for kitchen counter outlets (and used
to be fairly common practise in the US). This has only changed in Canada
because of new requirements for GFCIs on kitchen counter outlets, and GFCI'ing
split duplex receptacles requires expensive dual GFCI breakers.

If the hots are equal current, the current in the neutral wire is _zero_.
Not only that, but the voltage between neutral and ground will also be _zero_[+].

[+] presuming of course that the neutral and ground are properly connected
to where they're supposed to be - connected together at the main
panel.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.

"Chris Lewis" wrote in message
...
According to Tony :

"Tony" wrote in message
news:xfHwi.7146$xc5.2631@trnddc06...

"Chris Friesen" wrote in message
...
Tony wrote:

and neutral at properly design and grounded system
IS carrying current it is not at zero ever unless on your
screwed up system ground is carrying current
which is not suppose to ever.

Not true. The two hots in a 240V circuit are 180 degrees out of
phase.
Only the difference between the loads on the two sides flows through
the
neutral. Thus, if you have equal 120V loads on each side, the neutral
will have zero current flowing in it.

I would like wet one of "YOU" hand put it on the ground
ant other to the neutral to see if is carrying current
in close loop circuit and use something small to close
loop like 100 watt bulb that should do it
yes why don't try that and let us know
because what you saying 0 potential 0 current
that should be perfectly safe

Even after spelling and gramatical corrections, that's linguistically and
technically wrong, not to mention just plain silly.

Even if the neutral was carrying current, you're not going to get a shock
between the neutral and ground because the voltage difference between the
neutral and ground is at most a volt or two[+]. This is true even in a
120V
circuit pulling 15A.

Sorry Chris for me it is kind hard to explain because of language barrier
I should have said that you open neutral from the source/panel
in other words you body would be in series with neutral leg/line
That is tied to the load in this case light bulb.
look easiest way to solve mystery is hook up one light bulb
and measure the current on both wires and you will find
that both weirs have same current flow, that's easy enough,



Remember, the neutral and ground are connected together in the panel.
They're never going to be more than a volt or two different. Unless
something goes very wrong.

The neutral in a 3 wire 240V/120V circuit only carries the difference
current between the two hots. If it wasn't and currents added on the
neutral, then 3 wire 240V/120V circuits would be illegal. I assure you,
they're not. In fact, up until a few years ago, they were _mandatory_
in the Canadian electrical code for kitchen counter outlets (and used
to be fairly common practise in the US). This has only changed in Canada
because of new requirements for GFCIs on kitchen counter outlets, and
GFCI'ing
split duplex receptacles requires expensive dual GFCI breakers.

If the hots are equal current, the current in the neutral wire is _zero_.
Not only that, but the voltage between neutral and ground will also be
_zero_[+].

[+] presuming of course that the neutral and ground are properly connected
to where they're supposed to be - connected together at the main
panel.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.

Tony wrote:

look easiest way to solve mystery is hook up one light bulb
and measure the current on both wires and you will find
that both weirs have same current flow, that's easy enough,

In a 3-wire circuit you have two hots and a neutral. If you put a light
bulb between each of the hots and the neutral, there will be no current
flow in the neutral.

In essence, the current flows up one hot, through the bulb, through the
other bulb, and back down the other hot. (It's like one hot is
positive, the other is negative, and the neutral is zero.)

The neutral is only needed for the case where the load on each of the
hot legs is not equal.

Chris

"Chris Friesen" wrote in message
...
Tony wrote:

look easiest way to solve mystery is hook up one light bulb
and measure the current on both wires and you will find
that both weirs have same current flow, that's easy enough,

In a 3-wire circuit you have two hots and a neutral. If you put a light
bulb between each of the hots and the neutral, there will be no current
flow in the neutral.

O yes it will and twice the hot legs, as I siad try and do little
expirement on your onw and find out for your self
Tony


In essence, the current flows up one hot, through the bulb, through the
other bulb, and back down the other hot. (It's like one hot is positive,
the other is negative, and the neutral is zero.)

The neutral is only needed for the case where the load on each of the hot
legs is not equal.

Chris

Tony wrote:
"Chris Friesen" wrote in message
...
Tony wrote:

look easiest way to solve mystery is hook up one light bulb
and measure the current on both wires and you will find
that both weirs have same current flow, that's easy enough,

In a 3-wire circuit you have two hots and a neutral. If you put a
light bulb between each of the hots and the neutral, there will be
no current flow in the neutral.

O yes it will and twice the hot legs, as I siad try and do little
expirement on your onw and find out for your self
Tony


In essence, the current flows up one hot, through the bulb, through
the other bulb, and back down the other hot. (It's like one hot is
positive, the other is negative, and the neutral is zero.)

The neutral is only needed for the case where the load on each of
the hot legs is not equal.

Chris

And here I thought the 3-wire line from the pole was a center tap 220 volt
transformer with the load carrying neatrul being the center tap [110
volts.]. Learn something new each day.

--
Zyp

Zyp wrote:

And here I thought the 3-wire line from the pole was a center tap 220 volt
transformer with the load carrying neatrul being the center tap [110
volts.]. Learn something new each day.

Just to clarify...it is a center-tap 220V (or 240V) transformer.
However, the center tap is tied to ground. The two hots alternate
positive and negative, but exactly opposite from each other.

Chris

Tony wrote:
"Chris Friesen" wrote

In a 3-wire circuit you have two hots and a neutral. If you put a light
bulb between each of the hots and the neutral, there will be no current
flow in the neutral.

O yes it will and twice the hot legs, as I siad try and do little
expirement on your onw and find out for your self
Tony

I honestly can't tell if you're a troll or not.

If the neutral could carry twice the current of the hots in normal use,
then it would have to be a larger conductor than the hots.

In reality, the neutral in a feeder line is often *undersized* relative
to the hots. This is because it only carries the difference between the
two hots, and if you have balanced loads or 240V loads there is no
current in the neutral.

If that isn't enough of an explanation, I give up. This thread has gone
long enough. Please don't do your own wiring.

Chris

Chris we are not going any way so I am not going to comment
however? there is no such thing in AC circuit as positive
and negative the on three phase system or single phase,
the phases are out of phase by 90 degree
that is it! no positive or negative
just about 6-7 months ago I had job replacing 25 hp Refrigeration
compressor that runs on 480 three phase and guess what
one phase was neutral, amazing isn't and you telling me
neutral is not carrying current I afraid you will need eat few more Winnies
by have nice day Tony


"Chris Friesen" wrote in message
...
Tony wrote:
"Chris Friesen" wrote

In a 3-wire circuit you have two hots and a neutral. If you put a light
bulb between each of the hots and the neutral, there will be no current
flow in the neutral.

O yes it will and twice the hot legs, as I siad try and do little
expirement on your onw and find out for your self
Tony

I honestly can't tell if you're a troll or not.

If the neutral could carry twice the current of the hots in normal use,
then it would have to be a larger conductor than the hots.

In reality, the neutral in a feeder line is often *undersized* relative to
the hots. This is because it only carries the difference between the two
hots, and if you have balanced loads or 240V loads there is no current in
the neutral.

If that isn't enough of an explanation, I give up. This thread has gone
long enough. Please don't do your own wiring.

Chris

Tony wrote:
"Chris Friesen" wrote in message
...

Tony wrote:


look easiest way to solve mystery is hook up one light bulb
and measure the current on both wires and you will find
that both weirs have same current flow, that's easy enough,

In a 3-wire circuit you have two hots and a neutral. If you put a light
bulb between each of the hots and the neutral, there will be no current
flow in the neutral.


O yes it will and twice the hot legs, as I siad try and do little
expirement on your onw and find out for your self
Tony

Have YOU tried that experiment?



In essence, the current flows up one hot, through the bulb, through the
other bulb, and back down the other hot. (It's like one hot is positive,
the other is negative, and the neutral is zero.)

The neutral is only needed for the case where the load on each of the hot
legs is not equal.

Chris





--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

Tony wrote:

Chris we are not going any way so I am not going to comment
however? there is no such thing in AC circuit as positive
and negative the on three phase system or single phase,
the phases are out of phase by 90 degree
that is it! no positive or negative
just about 6-7 months ago I had job replacing 25 hp Refrigeration
compressor that runs on 480 three phase and guess what
one phase was neutral, amazing isn't and you telling me
neutral is not carrying current I afraid you will need eat few more Winnies
by have nice day Tony


May I suggest you read this: ?

http://en.wikipedia.org/wiki/Split_phase


"Chris Friesen" wrote in message
...

Tony wrote:

"Chris Friesen" wrote

In a 3-wire circuit you have two hots and a neutral. If you put a light
bulb between each of the hots and the neutral, there will be no current
flow in the neutral.

O yes it will and twice the hot legs, as I siad try and do little
expirement on your onw and find out for your self
Tony

I honestly can't tell if you're a troll or not.

If the neutral could carry twice the current of the hots in normal use,
then it would have to be a larger conductor than the hots.

In reality, the neutral in a feeder line is often *undersized* relative to
the hots. This is because it only carries the difference between the two
hots, and if you have balanced loads or 240V loads there is no current in
the neutral.

If that isn't enough of an explanation, I give up. This thread has gone
long enough. Please don't do your own wiring.

Chris





--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

"Tony" wrote in message
news:2Ymxi.18$A57.15@trnddc04...
Chris we are not going any way so I am not going to comment
however? there is no such thing in AC circuit as positive
and negative the on three phase system or single phase,
the phases are out of phase by 90 degree
that is it! no positive or negative
just about 6-7 months ago I had job replacing 25 hp Refrigeration
compressor that runs on 480 three phase and guess what
one phase was neutral, amazing isn't and you telling me
neutral is not carrying current I afraid you will need eat few more
Winnies
by have nice day Tony




sounds like a "b" phase ground
a and c phase to ground 480v
b phase 0v



In 3 phase panels you can also have a high phase
between a and b
b and c
a and c all 240v
a and c to neutral 120v
b to neutral 240v

problem is Chris is still right

Tony wrote:
Chris we are not going any way so I am not going to comment
however? there is no such thing in AC circuit as positive
and negative the on three phase system or single phase,
the phases are out of phase by 90 degree
that is it! no positive or negative
just about 6-7 months ago I had job replacing 25 hp Refrigeration
compressor that runs on 480 three phase and guess what
one phase was neutral, amazing isn't and you telling me
neutral is not carrying current I afraid you will need eat few more Winnies
by have nice day Tony




He is simply trying to give you a simplified analogy.

The legs on a three phase system are 120 degrees out of phase with each
other. On a single phase system the legs are 180 degrees out of phase
with each other.

"George" wrote in message
. ..

.. On a single phase system the legs are 180 degrees out of phase
with each other.

When you say this you need to add ", referenced to ground (neutral)"

On Aug 17, 8:04 pm, George wrote:
Tony wrote:
Chris we are not going any way so I am not going to comment
however? there is no such thing in AC circuit as positive
and negative the on three phase system or single phase,
the phases are out of phase by 90 degree
that is it! no positive or negative
just about 6-7 months ago I had job replacing 25 hp Refrigeration
compressor that runs on 480 three phase and guess what
one phase was neutral, amazing isn't and you telling me
neutral is not carrying current I afraid you will need eat few more Winnies
by have nice day Tony

He is simply trying to give you a simplified analogy.

The legs on a three phase system are 120 degrees out of phase with each
other. On a single phase system the legs are 180 degrees out of phase
with each other.


I can't believe you guys have taken this crazy discussion with Tony to
3 phases. He obviously doesn't even understand 2 phases. When he
said:

"It is been so long since I stody the basics of Kirechhoffs Law,
That I would not atempt to go there
Tony "

it became obvious he's totally unqualified to be giving advice or
opinions on current flowing in a shared neutral. Kirchoff's Law is
quite simple and elementary: The sum of all currents at any node must
be zero. Which is to say, current can't pile up, it has to go
somewhere. In the case of a 240V shared neutral settup, that means
whatever current goes up one hot must either go back on the other hot,
which is out of phase or back via the neutral.

And to go back to the example Chris gave earlier, on a shared neutral,
if you put a 100W light bulb from one hot to neutral and another 100W
light bulb on the other hot to neutral, you will have zero amps
flowing in the neutral because the load is balanced. The current
flows from one hot, through the first bulb, through the second and
back via the other hot.

Now connect another light bulb from one hot to neutral, then you will
have current flow in the neutral.

Very basic.

In article , "SRN" wrote:

"George" wrote in message
...

.. On a single phase system the legs are 180 degrees out of phase
with each other.

When you say this you need to add ", referenced to ground (neutral)"

No, you don't. The statement refers solely to the phase difference between the
two hot legs, which has absolutely nothing to do with either's potential
difference from neutral.

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

It's time to throw all their damned tea in the harbor again.

Chris Friesen wrote:
Zyp wrote:

And here I thought the 3-wire line from the pole was a center tap
220 volt transformer with the load carrying neatrul being the center
tap [110 volts.]. Learn something new each day.

Just to clarify...it is a center-tap 220V (or 240V) transformer.
However, the center tap is tied to ground. The two hots alternate
positive and negative, but exactly opposite from each other.

Chris

Hmmm... you're sort of right, they do "alternate" but 60 times a second.
What's the frequency of the AC current got to do with it?

--
Zyp

wrote:
On Aug 17, 8:04 pm, George wrote:
Tony wrote:
Chris we are not going any way so I am not going to comment
however? there is no such thing in AC circuit as positive
and negative the on three phase system or single phase,
the phases are out of phase by 90 degree
that is it! no positive or negative
just about 6-7 months ago I had job replacing 25 hp Refrigeration
compressor that runs on 480 three phase and guess what
one phase was neutral, amazing isn't and you telling me
neutral is not carrying current I afraid you will need eat few more
Winnies by have nice day Tony

He is simply trying to give you a simplified analogy.

The legs on a three phase system are 120 degrees out of phase with
each other. On a single phase system the legs are 180 degrees out
of phase with each other.


I can't believe you guys have taken this crazy discussion with Tony to
3 phases. He obviously doesn't even understand 2 phases. When he
said:

"It is been so long since I stody the basics of Kirechhoffs Law,
That I would not atempt to go there
Tony "

it became obvious he's totally unqualified to be giving advice or
opinions on current flowing in a shared neutral. Kirchoff's Law is
quite simple and elementary: The sum of all currents at any node must
be zero. Which is to say, current can't pile up, it has to go
somewhere. In the case of a 240V shared neutral settup, that means
whatever current goes up one hot must either go back on the other hot,
which is out of phase or back via the neutral.

And to go back to the example Chris gave earlier, on a shared neutral,
if you put a 100W light bulb from one hot to neutral and another 100W
light bulb on the other hot to neutral, you will have zero amps
flowing in the neutral because the load is balanced. The current
flows from one hot, through the first bulb, through the second and
back via the other hot.

Now connect another light bulb from one hot to neutral, then you will
have current flow in the neutral.

Very basic.

Thank you!

--
Zyp

Tony wrote:
"Chris Friesen" wrote in message
...
Tony wrote:

look easiest way to solve mystery is hook up one light bulb
and measure the current on both wires and you will find
that both weirs have same current flow, that's easy enough,
In a 3-wire circuit you have two hots and a neutral. If you put a light
bulb between each of the hots and the neutral, there will be no current
flow in the neutral.

O yes it will and twice the hot legs, as I siad try and do little
expirement on your onw and find out for your self
Tony

In essence, the current flows up one hot, through the bulb, through the
other bulb, and back down the other hot. (It's like one hot is positive,
the other is negative, and the neutral is zero.)

The neutral is only needed for the case where the load on each of the hot
legs is not equal.

Chris



Tony
You are off your soundings there bud. In case your not nautically
inclined that means you are out of your depth. If you wire two sixty
watt bulbs in series across a two forty volt circuit they will burn just
fine. Now connect a neutral to the connection that is between the two
bulbs and if the bulbs are truly identical then no current will flow on
the neutral.

Here's a little experiment for you to try. You can build an Edison
circuit from two twelve volt batteries and two twelve volt lamps. Wire
them all in series. The two twelve volt lights will light just fine.
connect a volt meter across the connection between the lights and the
connection between the batteries. It will measure six volts. Now
change the leads and settings on your multimeter from voltage to current
and measure across the same two points. Applying the ammeter as a
neutral conductor will not change the current significantly.
The only current flowing will be caused by the slight differences in
manufacture between the two lights and the two batteries.
--
Tom Horne

"Chris Friesen" wrote
In a 3-wire circuit you have two hots and a neutral. If you put a light
bulb between each of the hots and the neutral, there will be no current
flow in the neutral.
O yes it will and twice the hot legs, as I siad try and do little
expirement on your onw and find out for your self
Tony
"Chris Friesen" wrote in message
...
I honestly can't tell if you're a troll or not.

If the neutral could carry twice the current of the hots in normal use,
then it would have to be a larger conductor than the hots.

In reality, the neutral in a feeder line is often *undersized* relative to
the hots. This is because it only carries the difference between the two
hots, and if you have balanced loads or 240V loads there is no current in
the neutral.

If that isn't enough of an explanation, I give up. This thread has gone
long enough. Please don't do your own wiring.

Chris


Tony wrote:
Chris we are not going any way so I am not going to comment
however? there is no such thing in AC circuit as positive
and negative the on three phase system or single phase,
the phases are out of phase by 90 degree
that is it! no positive or negative
just about 6-7 months ago I had job replacing 25 hp Refrigeration
compressor that runs on 480 three phase and guess what
one phase was neutral, amazing isn't and you telling me
neutral is not carrying current I afraid you will need eat few more
Winnies by have nice day Tony


Tony
If you think all grounded current carrying conductors are neutrals then
you are inadequately trained. A corner grounded Delta transformer set,
such as the one that probably supplied your refrigeration compressor,
cannot supply a neutral. The only time phases will be ninety degrees
out of phase is in a Scot T transformer arrangement.

The two hundred and forty volt, single phase, transformers that are used
to supply homes in North American practice are supplied from a single
phase on the primary side. How can a transformer with only two windings
produce a phase difference across it's output winding?

If you have worked with buck boost transformers you know that a single
phase transformer can be tapped on it's secondary side to supply several
different voltages and although it is rarely done those different
voltages can be from the same transformer secondary. I could ground any
one of the taps as long as I ground only one without effecting the
voltage output available from each portion of the secondary winding. If
it produces several voltages on it's output does that make it multi
phase? Voltage is usually measured to ground because it is that voltage
the insulation must successfully withstand. If you measure the outputs
against each other using an oscilloscope you will find that the wave
forms are identical in the horizontal or time domain and that they
differ only in their amplitude as an expression of their voltage.
--
Tom Horne