If you have a 2 wire house electrical system what's the difference between a
3 wire system and installing a 3wire plug and jumping the ground pin to the
white return line. I see no electrical difference between that and running a
green wire all the way to the box and connecting it to the same place as the
return line ground. If you know what I mean.


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Rodney Kelp wrote:
If you have a 2 wire house electrical system what's the difference between a
3 wire system and installing a 3wire plug and jumping the ground pin to the
white return line. I see no electrical difference between that and running a
green wire all the way to the box and connecting it to the same place as the
return line ground. If you know what I mean.

If the neutral wire ever comes loose then the appliance becomes
electrified. Don't do it, it is very dangerous.


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Rodney Kelp wrote:
If you have a 2 wire house electrical system what's the difference between a
3 wire system and installing a 3wire plug and jumping the ground pin to the
white return line. I see no electrical difference between that and running a
green wire all the way to the box and connecting it to the same place as the
return line ground. If you know what I mean.


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Consider the possible failure modes. It's called a "safety ground"
for a reason.

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The e-mail address in our reply-to line is reversed in an attempt to
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"Rodney Kelp" wrote in message
...
| If you have a 2 wire house electrical system what's the difference between
a
| 3 wire system and installing a 3wire plug and jumping the ground pin to
the
| white return line. I see no electrical difference between that and running
a
| green wire all the way to the box and connecting it to the same place as
the
| return line ground. If you know what I mean.

The difference is that it violates code and can result in your insurance
being voided in case of fire or accident. See if the box is grounded, and if
so you can use that as the ground.

N

As far as you don't use anything else than a __ dedicated wire connected to
the earth network of your house or building __ which impedance is low
enough forget about it !

50 to 100 Ohms look good for an earth ground. It may increase up to 1000
Ohms or more in
a dry rock soil. It's up to you to wet the earth pole.

I think that your white return line is the neutral wire. With the exception
of very specific cases it isn't connected to the earth. PROHIBITED and
DANGEROUS to use an existing wire in a two-wire line. In some cases it may
raise pretty high above the earth equipotential. Moreover you aren't free of
any error committed by an employee resulting in the application of the live
to your equipment case. Don't forget that a mains line is not polarized.



----- Original Message -----
From: "Rodney Kelp"
Newsgroups: sci.electronics.repair
Sent: Friday, November 12, 2004 4:14 PM
Subject: Grounding


If you have a 2 wire house electrical system what's the difference between
a
3 wire system and installing a 3wire plug and jumping the ground pin to
the
white return line. I see no electrical difference between that and running
a
green wire all the way to the box and connecting it to the same place as
the
return line ground. If you know what I mean.

"Rodney Kelp" writes:

If you have a 2 wire house electrical system what's the difference between a
3 wire system and installing a 3wire plug and jumping the ground pin to the
white return line. I see no electrical difference between that and running a
green wire all the way to the box and connecting it to the same place as the
return line ground. If you know what I mean.

Functionally, there is little difference. However, safety-wise, they
are a world apart.

Nothing a user can come in contact with should ever be attached to
Hot or Neutral.

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
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If you look inside some power panels the white neutral is connected to the
same terminal block as the green ground wires.
What's the diff?

"Sam Goldwasser" wrote in message
...
"Rodney Kelp" writes:

If you have a 2 wire house electrical system what's the difference
between a
3 wire system and installing a 3wire plug and jumping the ground pin to
the
white return line. I see no electrical difference between that and
running a
green wire all the way to the box and connecting it to the same place as
the
return line ground. If you know what I mean.

Functionally, there is little difference. However, safety-wise, they
are a world apart.

Nothing a user can come in contact with should ever be attached to
Hot or Neutral.

--- sam | Sci.Electronics.Repair FAQ Mirror:
http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ:
http://repairfaq.ece.drexel.edu/sam/lasersam.htm
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Rodney Kelp wrote:
If you look inside some power panels the white neutral is connected to the
same terminal block as the green ground wires.
What's the diff?

That connection is on the power panel end of the wire is the difference.

There's also a connection to earth ground at that same point.

Consider the possible failure modes at the appliance end of the wire.

It's a _safety_ issue.

"Sam Goldwasser" wrote in message
...

"Rodney Kelp" writes:


If you have a 2 wire house electrical system what's the difference

between a

3 wire system and installing a 3wire plug and jumping the ground pin to

the

white return line. I see no electrical difference between that and

running a

green wire all the way to the box and connecting it to the same place as

the

return line ground. If you know what I mean.

Functionally, there is little difference. However, safety-wise, they
are a world apart.

Nothing a user can come in contact with should ever be attached to
Hot or Neutral.

--- sam | Sci.Electronics.Repair FAQ Mirror:

http://repairfaq.ece.drexel.edu/

Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ:

http://repairfaq.ece.drexel.edu/sam/lasersam.htm

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excessive

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ignored.

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"Rodney Kelp" wrote in message
...
| If you look inside some power panels the white neutral is connected to the
| same terminal block as the green ground wires.
| What's the diff?

The difference is that it violates code and can result in your insurance
being voided in case of fire or accident. You may also be liable for death
or injury to other persons or loss of property.

This is called a multiple earthed (grounded) neutral system. It is carefully
designed to provide maximum safety for persons and property. The rules are
not arbitrary, not pointless, they are there for a reason. Ask 100
electricians - or 100,000 - and they will all tell you what you are
suggesting is wrong, dangerous and stupid. The neutral is grounded in very
specific places according to very specific rules.

I am a registered electrician as well as an electronics technician (in more
than one country) and I understand this system as well as anyone. You have
been told not to try this and given several reasons why. You have also been
told the right way to proceed. Believe those who advise you - they are
correct. Ask your local electrical inspector if you don't believe us.

If you insist on this foolish procedure, I suggest you practice first by
checking the level of gas in your tank with a lighted match.

NM

On Fri, 12 Nov 2004 20:25:20 -0500, "Rodney Kelp"
wrote:

If you look inside some power panels the white neutral is connected to the
same terminal block as the green ground wires.
What's the diff?

Perhaps you should do some reading on the MEN system. Here is an
publication from Australia which illustrates the hazards and reasons
for using it.

http://www.eso.qld.gov.au/publicat/men/men1.pdf

No matter where you live, if your electrical supply uses the MEN
system it will be very similar even for 115V.






"Sam Goldwasser" wrote in message
...
"Rodney Kelp" writes:

If you have a 2 wire house electrical system what's the difference
between a
3 wire system and installing a 3wire plug and jumping the ground pin to
the
white return line. I see no electrical difference between that and
running a
green wire all the way to the box and connecting it to the same place as
the
return line ground. If you know what I mean.

Functionally, there is little difference. However, safety-wise, they
are a world apart.

Nothing a user can come in contact with should ever be attached to
Hot or Neutral.

--- sam | Sci.Electronics.Repair FAQ Mirror:
http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ:
http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites:
http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

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excessive
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Important: Anything sent to the email address in the message header is
ignored.
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If you look inside some power panels the white neutral is connected to the
same terminal block as the green ground wires.
What's the diff?

OK there's been 100 explanations now how grounding to the white wire will "kill
you, start a fire, cause a neuclier explosion ect." I'm still in the dark too.
If ground is on the white and also on the green, what the heck does it matter?
Not trying to be a moron, but these electrical codes are beyond me, living in a
house built in 1898, I'd be surprised if there's even a hint of *code* here,
but no problems.

"RonKZ650" wrote in message
...
| If you look inside some power panels the white neutral is connected to
the
| same terminal block as the green ground wires.
| What's the diff?
|
| OK there's been 100 explanations now how grounding to the white wire will
"kill
| you, start a fire, cause a neuclier explosion ect." I'm still in the dark
too.
| If ground is on the white and also on the green, what the heck does it
matter?
| Not trying to be a moron, but these electrical codes are beyond me, living
in a
| house built in 1898, I'd be surprised if there's even a hint of *code*
here,
| but no problems.

Even in the days of knob and tube wiring (the earliest type) there was a
code at least of sorts. Learning from every accident and fire has produced
the code we have today which aims to minimize those problems.

Hey, I feel I can drive perfectly safely at 120 MPH while the rest of the
traffic is doing 70 MPH. So why shouldn't I? It's only a rule, right? And if
you feel the same way why shouldn't you do whatever you please? After all,
red light, green light, they're just colors. Go when you feel like it. No
problem. And who says you need to drive on the right hand side of the road?

And anyone can be a doctor too. Why waste time at medical school? How hard
can it be?

Right.

N

"Leonard Martin" wrote in message
...

| Yes, it would be nice if someone would undertake to answer your question
| by explaining. a little about electrical wiring conventions in general
| and grounding in particular. I know something about electronics, but
| I've never found a good (short) explanation of even the basics of house
| wiring and grounding.

See the previously mentioned http://www.eso.qld.gov.au/publicat/men/men1.pdf

Here are a couple of cases I know of:

1) The city replaces the wires to the house, but accidentally connects the
hot to the neutral and the neutral to the hot. Now all of your 'grounded'
appliances have 120 volts on each metal surface. I know the people this
happened to. They put an old fashioned metal bucket in the kitchen sink and
dropped the metal handle across the hot and cold taps. It promptly welded
itself to them.

2) A 15,000 volt overhead wire breaks and drops on the 120 volt wires
feeding your house. You still want to take your chances? This also happened.

The MEN system is the safest we have been able to come up with, but the
rules must be followed.

N

It seems to me that if a 15,000 volt line falls across your house feed it
will probably connect to the bare neutral and make all the little green
wires in your house 15k volts also.


"NSM" wrote in message
news:tOild.149834$df2.146141@edtnps89...

"Leonard Martin" wrote in message
...

| Yes, it would be nice if someone would undertake to answer your question
| by explaining. a little about electrical wiring conventions in general
| and grounding in particular. I know something about electronics, but
| I've never found a good (short) explanation of even the basics of house
| wiring and grounding.

See the previously mentioned
http://www.eso.qld.gov.au/publicat/men/men1.pdf

Here are a couple of cases I know of:

1) The city replaces the wires to the house, but accidentally connects the
hot to the neutral and the neutral to the hot. Now all of your 'grounded'
appliances have 120 volts on each metal surface. I know the people this
happened to. They put an old fashioned metal bucket in the kitchen sink
and
dropped the metal handle across the hot and cold taps. It promptly welded
itself to them.

2) A 15,000 volt overhead wire breaks and drops on the 120 volt wires
feeding your house. You still want to take your chances? This also
happened.

The MEN system is the safest we have been able to come up with, but the
rules must be followed.

N




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The greatest danger would be as you say, someone connecting the feed lines
backwards putting the neutral and hot lines in reverse. That kind of mistake
from a licenced electrician though, would be a grave violation of code and a
powerful demonstration of stupidity.


"NSM" wrote in message
news:tOild.149834$df2.146141@edtnps89...

"Leonard Martin" wrote in message
...

| Yes, it would be nice if someone would undertake to answer your question
| by explaining. a little about electrical wiring conventions in general
| and grounding in particular. I know something about electronics, but
| I've never found a good (short) explanation of even the basics of house
| wiring and grounding.

See the previously mentioned
http://www.eso.qld.gov.au/publicat/men/men1.pdf

Here are a couple of cases I know of:

1) The city replaces the wires to the house, but accidentally connects the
hot to the neutral and the neutral to the hot. Now all of your 'grounded'
appliances have 120 volts on each metal surface. I know the people this
happened to. They put an old fashioned metal bucket in the kitchen sink
and
dropped the metal handle across the hot and cold taps. It promptly welded
itself to them.

2) A 15,000 volt overhead wire breaks and drops on the 120 volt wires
feeding your house. You still want to take your chances? This also
happened.

The MEN system is the safest we have been able to come up with, but the
rules must be followed.

N




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The original question was " is it electrically the same" Not is it legally
the same.


"NSM" wrote in message
news:Rafld.149325$df2.113298@edtnps89...

"Rodney Kelp" wrote in message
...
| If you look inside some power panels the white neutral is connected to
the
| same terminal block as the green ground wires.
| What's the diff?

The difference is that it violates code and can result in your insurance
being voided in case of fire or accident. You may also be liable for death
or injury to other persons or loss of property.

This is called a multiple earthed (grounded) neutral system. It is
carefully
designed to provide maximum safety for persons and property. The rules are
not arbitrary, not pointless, they are there for a reason. Ask 100
electricians - or 100,000 - and they will all tell you what you are
suggesting is wrong, dangerous and stupid. The neutral is grounded in very
specific places according to very specific rules.

I am a registered electrician as well as an electronics technician (in
more
than one country) and I understand this system as well as anyone. You have
been told not to try this and given several reasons why. You have also
been
told the right way to proceed. Believe those who advise you - they are
correct. Ask your local electrical inspector if you don't believe us.

If you insist on this foolish procedure, I suggest you practice first by
checking the level of gas in your tank with a lighted match.

NM





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"Rodney Kelp" wrote in message
...
The original question was " is it electrically the same" Not is it legally
the same.

But the real point is that it is not electrically the same in the case of a
failure of the neutral line.

Leonard

Rodney Kelp wrote:
The original question was " is it electrically the same" Not is it legally
the same.


It's not even electrically the same, because the wires are not ideal.

So neutral won't be at the same potential as safety ground.

However, from the point of view of an appliance, that shouldn't matter.


"NSM" wrote in message
news:Rafld.149325$df2.113298@edtnps89...

"Rodney Kelp" wrote in message
...
| If you look inside some power panels the white neutral is connected to

the

| same terminal block as the green ground wires.
| What's the diff?

The difference is that it violates code and can result in your insurance
being voided in case of fire or accident. You may also be liable for death
or injury to other persons or loss of property.

This is called a multiple earthed (grounded) neutral system. It is

carefully

designed to provide maximum safety for persons and property. The rules are
not arbitrary, not pointless, they are there for a reason. Ask 100
electricians - or 100,000 - and they will all tell you what you are
suggesting is wrong, dangerous and stupid. The neutral is grounded in very
specific places according to very specific rules.

I am a registered electrician as well as an electronics technician (in

more

than one country) and I understand this system as well as anyone. You have
been told not to try this and given several reasons why. You have also

been

told the right way to proceed. Believe those who advise you - they are
correct. Ask your local electrical inspector if you don't believe us.

If you insist on this foolish procedure, I suggest you practice first by
checking the level of gas in your tank with a lighted match.

NM






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--
The e-mail address in our reply-to line is reversed in an attempt to
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Here's one example:

Consider the 'appliance' below:

+-----------------+
| | Open Fault
Hot o---------o-o----/\/\---------+------ X -----o Neutral
| Switch Load | |
| (On) |----+ Case should be G but is connected to N
+-----------------+


With the appliance 'on', current passes through the internal
wiring/motor/etc. of the appliance to the N but this is now connected
to the case as well. If the house wiring opens (or even if the plug is
loose, it is possible to have line voltage on the case.

The 'appliance' can actually be *all* loads on the circuit upstream of
the the Open Fault - all those with a grounded cabinet have it then
become live! Testing installed GFCIs

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
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Important: Anything sent to the email address in the message header is ignored.
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"Rodney Kelp" wrote in message
...
| The greatest danger would be as you say, someone connecting the feed lines
| backwards putting the neutral and hot lines in reverse. That kind of
mistake
| from a licenced electrician though, would be a grave violation of code and
a
| powerful demonstration of stupidity.

But as they say, **** happens. In each case the occupants survived, as they
have in other cases. We don't have time to analyse each possible result from
each possible combination of faults or errors. We follow the code because
that represents the accumulated wisdom gained from all previous occurrences.
If we didn't need the code it wouldn't exist.

If the homeowner (or anyone else) doesn't follow the code, god help the next
poor ******* who tries to work on the electrical system. There is a very
popular show on TV in Canada called "Holmes on Homes" which shows some of
the nightmare results of not following all codes, electrical, plumbing and
building. Some of the stuff he has found could loosen the bowels of a
granite rock.

N

If you wanna get electrocuted it's your own right but make sure anyone isn't
using the same equipment.
I can't see the reason why you posted a question here since you're totally
convinced you're right and highly reluctant to any explanation.

I consider it's TROLL and drop your messages.



"Rodney Kelp" a écrit dans le message news:
...
The greatest danger would be as you say, someone connecting the feed lines
backwards putting the neutral and hot lines in reverse. That kind of
mistake
from a licenced electrician though, would be a grave violation of code and
a
powerful demonstration of stupidity.

"Simon Cussonnet" wrote in message
...
| If you wanna get electrocuted it's your own right but make sure anyone
isn't
| using the same equipment.
| I can't see the reason why you posted a question here since you're totally
| convinced you're right and highly reluctant to any explanation.
|
| I consider it's TROLL and drop your messages.

It's occurred to me that he's a troll, but he might just be criminally
stupid. There are plenty of people like that around - many of them working
as building contractors.

N

| If you look inside some power panels the white neutral is connected to
the
| same terminal block as the green ground wires.
| What's the diff?

The difference is that it violates code and can result in your insurance
being voided in case of fire or accident. You may also be liable for death
or injury to other persons or loss of property.

This is called a multiple earthed (grounded) neutral system. It is
carefully
designed to provide maximum safety for persons and property. The rules are
not arbitrary, not pointless, they are there for a reason. Ask 100
electricians - or 100,000 - and they will all tell you what you are
suggesting is wrong, dangerous and stupid. The neutral is grounded in very
specific places according to very specific rules.

I am a registered electrician as well as an electronics technician (in
more
than one country) and I understand this system as well as anyone. You have
been told not to try this and given several reasons why. You have also
been
told the right way to proceed. Believe those who advise you - they are
correct. Ask your local electrical inspector if you don't believe us.

If you insist on this foolish procedure, I suggest you practice first by
checking the level of gas in your tank with a lighted match.

NM


The OP simply posed an academic question; I see no suggestion that he
intends to tamper with his installation.

His arguments are clearly intended to evoke a response so he can understand
the situation better.

Isn't that the best way of learning?

You are being a bit hard on him.

Now shake hands and say sorry.


Graham.

"Graham" wrote in message
...

| The OP simply posed an academic question; I see no suggestion that he
| intends to tamper with his installation.
|
| His arguments are clearly intended to evoke a response so he can
understand
| the situation better.
|
| Isn't that the best way of learning?
|
| You are being a bit hard on him.
|
| Now shake hands and say sorry.

"If you have a 2 wire house electrical system what's the difference between
a 3 wire system and installing a 3 wire plug and jumping the ground pin to
the white return line. I see no electrical difference between that and
running a green wire all the way to the box and connecting it to the same
place as the return line ground. If you know what I mean."

Sounds like he was planning to rewire his house into a fool killer system to
me.

N

On Sat, 13 Nov 2004 21:11:10 GMT, "NSM" put finger to
keyboard and composed:

"Simon Cussonnet" wrote in message
.. .
| If you wanna get electrocuted it's your own right but make sure anyone
isn't
| using the same equipment.
| I can't see the reason why you posted a question here since you're totally
| convinced you're right and highly reluctant to any explanation.
|
| I consider it's TROLL and drop your messages.

It's occurred to me that he's a troll, but he might just be criminally
stupid. There are plenty of people like that around - many of them working
as building contractors.

AFAICS, the OP is not stupid, only ignorant of this particular
subject. IMO the question was a fair one that deserved an explanation
a little less condescending than "don't do it because it's not safe".
In fact, I'm betting that the majority of electricians don't
understand why they do things a certain way, they just blindly follow
rules.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

Appreciate that wire is not electrically same at both
ends. Wire is not a perfect conductor. Wire is treated as if
it was another electronic component. How much difference
exists between two ends of a wire is determined by
characteristics of the current in that wire - ie. amperes,
open circuit driving voltage, frequency, harmonics, etc. Most
of this will be well beyond the scope of this discussion.

But human safety demands that any electrical appliance be
connected as best as possible to the safety ground inside
breaker box panel (point where safety ground wires, white
neutral wire, utility neutral wire, and earth ground wire all
meet). The only wire that can make such a connection is one
that is not carrying any current - the bare ground wire. Even
though the white neutral wire also meets at that point, the
white wire has significant differences at both ends - because
white wire is carrying up to 20 amps current.

Others have provided examples of why the white wire and bare
safety ground wire are completely different wires at the wall
receptacle. Bottom line - the white wire and bare safety
ground wire are only same where both meet at the breaker box
safety ground.

You may even be able to see this difference with a digital
volt meter. When AC outlet powers a significant load (ie
toaster or steam iron), then a voltage difference should exist
between white neutral wire and bare copper safety ground wire
at that wall receptacle.

Are white neutral and bare copper safety wires properly
isolated? Breaker box GFCIs tend to trip (cut off power) when
bare copper white is shorted (connected) to white neutral wire
anywhere but inside the breaker box. Just another in a long
list of examples that demonstrate why white neutral and bare
copper safety ground wire are electrically different. Why one
wire cannot perform both functions.

Rodney Kelp wrote:
If you have a 2 wire house electrical system what's the difference
between a 3 wire system and installing a 3wire plug and jumping the
ground pin to the white return line. I see no electrical difference
between that and running a green wire all the way to the box and
connecting it to the same place as the return line ground. If you
know what I mean.

w_tom writes:

Appreciate that wire is not electrically same at both
ends. Wire is not a perfect conductor. Wire is treated as if
it was another electronic component. How much difference
exists between two ends of a wire is determined by
characteristics of the current in that wire - ie. amperes,
open circuit driving voltage, frequency, harmonics, etc. Most
of this will be well beyond the scope of this discussion.

But human safety demands that any electrical appliance be
connected as best as possible to the safety ground inside
breaker box panel (point where safety ground wires, white
neutral wire, utility neutral wire, and earth ground wire all
meet). The only wire that can make such a connection is one
that is not carrying any current - the bare ground wire. Even
though the white neutral wire also meets at that point, the
white wire has significant differences at both ends - because
white wire is carrying up to 20 amps current.

Others have provided examples of why the white wire and bare
safety ground wire are completely different wires at the wall
receptacle. Bottom line - the white wire and bare safety
ground wire are only same where both meet at the breaker box
safety ground.

You may even be able to see this difference with a digital
volt meter. When AC outlet powers a significant load (ie
toaster or steam iron), then a voltage difference should exist
between white neutral wire and bare copper safety ground wire
at that wall receptacle.

Are white neutral and bare copper safety wires properly
isolated? Breaker box GFCIs tend to trip (cut off power) when
bare copper white is shorted (connected) to white neutral wire
anywhere but inside the breaker box. Just another in a long
list of examples that demonstrate why white neutral and bare
copper safety ground wire are electrically different. Why one
wire cannot perform both functions.

It's more fundamental than this. Even if the wires were made of
superconductors, the rules would be equally valid for safety.

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traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header is ignored.
To contact me, please use the feedback form on the S.E.R FAQ Web sites.

Rodney Kelp wrote:
If you have a 2 wire house electrical system what's the difference
between a 3 wire system and installing a 3wire plug and jumping the
ground pin to the white return line. I see no electrical difference
between that and running a green wire all the way to the box and
connecting it to the same place as the return line ground. If you
know what I mean.

Ok, For those who worry, I am NOT wiring a house like this. This is only
theoretical.
So from what you say I see that the short jumper, on a 3 wire outlet,
from the green case ground post to the silver white neutral post has the
same potential as the bare copper safety wire has from the green case ground
post to the neutral binding posts in the breaker box panel.. Barring all
possible disasters Is there any electrical difference that the outlet sees
where you plug things in?
If the outlet is drawing 20 amps then isn't it felt at the breaker box paned
neutral connection where the equipment ground is connected?
As a matter of fact isn't the bare copper safety wire seeing the entire
house current at that neurtal connection in the breaker box panel at the
outlet's safety ground?

"w_tom" wrote in message
...
Appreciate that wire is not electrically same at both
ends. Wire is not a perfect conductor. Wire is treated as if
it was another electronic component. How much difference
exists between two ends of a wire is determined by
characteristics of the current in that wire - ie. amperes,
open circuit driving voltage, frequency, harmonics, etc. Most
of this will be well beyond the scope of this discussion.

But human safety demands that any electrical appliance be
connected as best as possible to the safety ground inside
breaker box panel (point where safety ground wires, white
neutral wire, utility neutral wire, and earth ground wire all
meet). The only wire that can make such a connection is one
that is not carrying any current - the bare ground wire. Even
though the white neutral wire also meets at that point, the
white wire has significant differences at both ends - because
white wire is carrying up to 20 amps current.

Others have provided examples of why the white wire and bare
safety ground wire are completely different wires at the wall
receptacle. Bottom line - the white wire and bare safety
ground wire are only same where both meet at the breaker box
safety ground.

You may even be able to see this difference with a digital
volt meter. When AC outlet powers a significant load (ie
toaster or steam iron), then a voltage difference should exist
between white neutral wire and bare copper safety ground wire
at that wall receptacle.

Are white neutral and bare copper safety wires properly
isolated? Breaker box GFCIs tend to trip (cut off power) when
bare copper white is shorted (connected) to white neutral wire
anywhere but inside the breaker box. Just another in a long
list of examples that demonstrate why white neutral and bare
copper safety ground wire are electrically different. Why one
wire cannot perform both functions.

Rodney Kelp wrote:
If you have a 2 wire house electrical system what's the difference
between a 3 wire system and installing a 3wire plug and jumping the
ground pin to the white return line. I see no electrical difference
between that and running a green wire all the way to the box and
connecting it to the same place as the return line ground. If you
know what I mean.


---
Outgoing mail is certified Virus Free.
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Appreciate that wire is not electrically same at both
ends. Wire is not a perfect conductor. Wire is treated as if
it was another electronic component. How much difference
exists between two ends of a wire is determined by
characteristics of the current in that wire - ie. amperes,
open circuit driving voltage, frequency, harmonics, etc. Most
of this will be well beyond the scope of this discussion.

But human safety demands that any electrical appliance be
connected as best as possible to the safety ground inside
breaker box panel (point where safety ground wires, white
neutral wire, utility neutral wire, and earth ground wire all
meet). The only wire that can make such a connection is one
that is not carrying any current - the bare ground wire. Even
though the white neutral wire also meets at that point, the
white wire has significant differences at both ends - because
white wire is carrying up to 20 amps current.

Others have provided examples of why the white wire and bare
safety ground wire are completely different wires at the wall
receptacle. Bottom line - the white wire and bare safety
ground wire are only same where both meet at the breaker box
safety ground.

You may even be able to see this difference with a digital
volt meter. When AC outlet powers a significant load (ie
toaster or steam iron), then a voltage difference should exist
between white neutral wire and bare copper safety ground wire
at that wall receptacle.

Are white neutral and bare copper safety wires properly
isolated? Breaker box GFCIs tend to trip (cut off power) when
bare copper white is shorted (connected) to white neutral wire
anywhere but inside the breaker box. Just another in a long
list of examples that demonstrate why white neutral and bare
copper safety ground wire are electrically different. Why one
wire cannot perform both functions.



Doesn't a similar situation exist under the hood of your car?

Two wires emerge from the alternator, a thick one and a thin one, and both
go to the positive pole of the battery.
I wonder how many people have stood pondered why that might be?

Graham.

%Profound_observation%

No.
"... on a 3 wire outlet, from the green case ground post to the
silver white neutral post"
* DOES NOT HAVE *
" ... the same potential as the bare copper safety wire has from
the green case ground post to the neutral binding posts in the
breaker box panel."
As posted earlier, the white wire and bare copper wire are
(essentially) same potential where they meet at breaker box -
the single point safety ground. Both wires have different
potential at their other (receptacle) end. That voltage
difference can even be measured with a digital volt meter when
the outlet is supporting a heavy load.

How 'different' at the far end? That answer first required
numbers - electrical parameters. Difference may be so slight
as to be unmeasureable or difference so great as to be a human
safety threat. But two wires with a common connection at one
end are not same (electrically speaking) as the other end.

Again, wire (even a superconductor wire) is an electronic
component - not a perfect conductor. Electricity at one end
of a wire is not same as at other end. To calculate the
difference, one must first apply numbers. But this difference
between two ends of any wire is why white wire cannot perform
the function of both white neutral and bare copper safety
ground. White wire and bare copper wire are wired so that
each conducts different electricity from different parts of
the same appliance. Both wires must remain separated so that
both wires conduct their electrically unique currents to the
same single point safety ground.

Do the experiment as posted previously. Connect a heavy
load to wall receptacle. Measure the AC voltage difference
between outlet safety ground and outlet neutral wire. Each
wire at the receptacle end have different potentials. 3.5
digit multimeters being so inexpensive and so ubiquitous that
anyone with a basic tool box has that meter - and can perform
this experiment.

If an outlet is drawing 20 amps, then everything in the
circuit is conducting 20 amps. BUT, the voltage (the
potential) between two wires is different at different
locations on the wire. Move one foot down a wire and the
voltage changes. Again, electricity even on one end of a one
foot wire is different at the other end. Difference may or
may not be measurable. But the difference always exists ...
because wire is another electronic component just like
resistors, capacitors, and inductors.

Rodney Kelp wrote:
Ok, For those who worry, I am NOT wiring a house like this. This is
only theoretical.
So from what you say I see that the short jumper, on a 3 wire outlet,
from the green case ground post to the silver white neutral post has
the same potential as the bare copper safety wire has from the green
case ground post to the neutral binding posts in the breaker box
panel. . Barring all possible disasters Is there any electrical
difference that the outlet sees where you plug things in?
If the outlet is drawing 20 amps then isn't it felt at the breaker
box paned neutral connection where the equipment ground is connected?
As a matter of fact isn't the bare copper safety wire seeing the
entire house current at that neurtal connection in the breaker box
panel at the outlet's safety ground?

Use the word 'kelvin' to further investigate this basic
electrical principle.

Graham wrote:
Doesn't a similar situation exist under the hood of your car?

Two wires emerge from the alternator, a thick one and a thin one,
and both go to the positive pole of the battery.
I wonder how many people have stood pondered why that might be?

Use the word 'kelvin' to further investigate this basic
electrical principle.

I thought he invented the temperature scale based on Absolute Zero.

Galvani (galvinism) perhaps???
Perhaps not.

--
Graham.



%Profound_observation%

"Franc Zabkar" wrote in message
...

| AFAICS, the OP is not stupid, only ignorant of this particular
| subject. IMO the question was a fair one that deserved an explanation
| a little less condescending than "don't do it because it's not safe".
| In fact, I'm betting that the majority of electricians don't
| understand why they do things a certain way, they just blindly follow
| rules.

Fortunately that works well. At one time during training they did understand
the reasons, and most do now, but as long as they follow the rules all will
work out well. In really unusual cases, the local inspector is the best
resource to ask for any needed variation, or an electrical engineer can be
hired.

I do understand the reasons to this day, but it's a long winded step by step
explanation and the previously given PDF goes into it in detail.

That rule is just one of many, MANY rules. Each has it's purpose and, while
I consider myself to be as smart as any electrician, I have no problem doing
the work to code.

BTW, I recall a case in which a bunch of farmers, a VERY long way away from
an electrical service, got permission to run electricity to their farms
using a single strand of fencing wire (carrying 11 KV) on the top of a
series of poles, and using the earth itself as the return wire. Believe me
there were some very careful considerations made before allowing this, but
it did work out OK in the end.

N

"Graham" wrote in message
...
|
|
| Use the word 'kelvin' to further investigate this basic
| electrical principle.
|
| I thought he invented the temperature scale based on Absolute Zero.

Search for (four-terminal kelvin connection) or (kelvin terminals) or
(kelvin clips) for better hits.

N

Rodney Kelp wrote:
Ok, For those who worry, I am NOT wiring a house like this. This is only
theoretical.
So from what you say I see that the short jumper,

There is (should be) no such jumper. Case closed.

If you see such a jumper, get your wiring reviewed by a competent
electrician before somebody gets electrocuted.

on a 3 wire outlet,
from the green case ground post to the silver white neutral post has the
same potential as the bare copper safety wire has from the green case ground
post to the neutral binding posts in the breaker box panel.. Barring all
possible disasters Is there any electrical difference that the outlet sees
where you plug things in?
If the outlet is drawing 20 amps then isn't it felt at the breaker box paned
neutral connection where the equipment ground is connected?
As a matter of fact isn't the bare copper safety wire seeing the entire
house current at that neurtal connection in the breaker box panel at the
outlet's safety ground?

I suppose that depends on what you mean by "seeing," but as you say,
it's just a theoretical question.


"w_tom" wrote in message
...

Appreciate that wire is not electrically same at both
ends. Wire is not a perfect conductor. Wire is treated as if
it was another electronic component. How much difference
exists between two ends of a wire is determined by
characteristics of the current in that wire - ie. amperes,
open circuit driving voltage, frequency, harmonics, etc. Most
of this will be well beyond the scope of this discussion.

But human safety demands that any electrical appliance be
connected as best as possible to the safety ground inside
breaker box panel (point where safety ground wires, white
neutral wire, utility neutral wire, and earth ground wire all
meet). The only wire that can make such a connection is one
that is not carrying any current - the bare ground wire. Even
though the white neutral wire also meets at that point, the
white wire has significant differences at both ends - because
white wire is carrying up to 20 amps current.

Others have provided examples of why the white wire and bare
safety ground wire are completely different wires at the wall
receptacle. Bottom line - the white wire and bare safety
ground wire are only same where both meet at the breaker box
safety ground.

You may even be able to see this difference with a digital
volt meter. When AC outlet powers a significant load (ie
toaster or steam iron), then a voltage difference should exist
between white neutral wire and bare copper safety ground wire
at that wall receptacle.

Are white neutral and bare copper safety wires properly
isolated? Breaker box GFCIs tend to trip (cut off power) when
bare copper white is shorted (connected) to white neutral wire
anywhere but inside the breaker box. Just another in a long
list of examples that demonstrate why white neutral and bare
copper safety ground wire are electrically different. Why one
wire cannot perform both functions.

Rodney Kelp wrote:

If you have a 2 wire house electrical system what's the difference
between a 3 wire system and installing a 3wire plug and jumping the
ground pin to the white return line. I see no electrical difference
between that and running a green wire all the way to the box and
connecting it to the same place as the return line ground. If you
know what I mean.



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
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--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

w_tom wrote:
No.

snip
Again, wire (even a superconductor wire) is an electronic
component - not a perfect conductor.
snip

You lost me there. Is "perfect" in this sentence something other than
zero resistance (e.g. it's only "perfect" to a buyer if free)?

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

Graham wrote:
snip

Doesn't a similar situation exist under the hood of your car?

Two wires emerge from the alternator, a thick one and a thin one, and both
go to the positive pole of the battery.

Are you saying they're connected to the same point on the alternator,
too? I doubt it.

I wonder how many people have stood pondered why that might be?

Graham.

%Profound_observation%




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

"Graham" wrote in message
...

| Two wires emerge from the alternator, a thick one and a thin one, and both
| go to the positive pole of the battery.
| I wonder how many people have stood pondered why that might be?

Not me. One is the high current output from the stator, the other is the
input to the regulator and thence to the rotor.

N

"w_tom" wrote in message
...
No.
"... on a 3 wire outlet, from the green case ground post to the
silver white neutral post"
* DOES NOT HAVE *

HAS- outlet plugs have two silver screws on one side and two gold screws on
the hot side. Some of them also have push pin holes in the back; 2 on the
silver side and 2 on the gold side.

" ... the same potential as the bare copper safety wire has from
the green case ground post to the neutral binding posts in the
breaker box panel."
As posted earlier, the white wire and bare copper wire are
(essentially) same potential where they meet at breaker box -
the single point safety ground. Both wires have different
potential at their other (receptacle) end. That voltage
difference can even be measured with a digital volt meter when
the outlet is supporting a heavy load.

How 'different' at the far end? That answer first required
numbers - electrical parameters. Difference may be so slight
as to be unmeasureable or difference so great as to be a human
safety threat. But two wires with a common connection at one
end are not same (electrically speaking) as the other end.

Again, wire (even a superconductor wire) is an electronic
component - not a perfect conductor. Electricity at one end
of a wire is not same as at other end. To calculate the
difference, one must first apply numbers. But this difference
between two ends of any wire is why white wire cannot perform
the function of both white neutral and bare copper safety
ground. White wire and bare copper wire are wired so that
each conducts different electricity from different parts of
the same appliance. Both wires must remain separated so that
both wires conduct their electrically unique currents to the
same single point safety ground.

Do the experiment as posted previously. Connect a heavy
load to wall receptacle. Measure the AC voltage difference
between outlet safety ground and outlet neutral wire. Each
wire at the receptacle end have different potentials. 3.5
digit multimeters being so inexpensive and so ubiquitous that
anyone with a basic tool box has that meter - and can perform
this experiment.

If an outlet is drawing 20 amps, then everything in the
circuit is conducting 20 amps. BUT, the voltage (the
potential) between two wires is different at different
locations on the wire. Move one foot down a wire and the
voltage changes. Again, electricity even on one end of a one
foot wire is different at the other end. Difference may or
may not be measurable. But the difference always exists ...
because wire is another electronic component just like
resistors, capacitors, and inductors.

Rodney Kelp wrote:
Ok, For those who worry, I am NOT wiring a house like this. This is
only theoretical.
So from what you say I see that the short jumper, on a 3 wire outlet,
from the green case ground post to the silver white neutral post has
the same potential as the bare copper safety wire has from the green
case ground post to the neutral binding posts in the breaker box
panel. . Barring all possible disasters Is there any electrical
difference that the outlet sees where you plug things in?
If the outlet is drawing 20 amps then isn't it felt at the breaker
box paned neutral connection where the equipment ground is connected?
As a matter of fact isn't the bare copper safety wire seeing the
entire house current at that neurtal connection in the breaker box
panel at the outlet's safety ground?


---
Outgoing mail is certified Virus Free.
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On Fri, 12 Nov 2004 20:25:20 -0500 "Rodney Kelp"
wrote:

If you look inside some power panels the white neutral is connected to the
same terminal block as the green ground wires.
What's the diff?

The connection between ground and neutral is made at exactly one
place, and that place is generally where the power comes into the
house, the service entrance.

After that point the ground and the neutral travel out to the rest of
the house to all the outlets that you have. The ground normally
carries no current, so there is no voltage drop between any point on
it and the actual ground at the service entrance.

The neutral carries current, so there will always be some voltage on
the neutral conductor. That voltage will depend on the distance from
the service entrance ground, the size of the conductor, and the amount
of return current being carried by the neutral. The voltage on the
neutral is usually less than 1 V, but it can be as much as 3-4 volts
in large installations with large currents.

While 3-4 volts would not be much of a safety hazard, think what would
happen if there was a problem with the neutral conductor somewhere
between your outlet and the service entrance. The voltage on the
neutral conductor would jump up to the line voltage. If you have
"grounded" your appliance to the neutral, then the external metal
parts of your appliance are now at line voltage.

For this reason, the code requires that the ground wire must not carry
any current except under fault conditions, and it also requires that
you not use the neutral to "ground" anything.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------