Want to install several X10 relay switches in the house to turn on lights remotely. This would obviate my walking across the room in the dark to get to the light switch.

Problem: The X10 switch/relay requires full power at the wall switch location. Several of my switches have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral wire into the box.
Question: Most of my wiring is within the attic and some of the switches are on the exterior walls. These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo providing mere inches of crawl space. It would be much easier to run the neutral wire from below (I have a generous 42" high crawl space).
Question: Does this neutral have to come from the same circuit? Can I simply come from any circuit (even a separate new circuit) and run a white neutral wire to each switch box? Does it have to be from the same phase? X10 docs. do mention that if not from the same phase, then the phases can be joined at the box.

All comments, advice and suggestions appreciated.

Ivan Vegvary

On Sep 16, 12:55 am, Ivan Vegvary wrote:
Want to install several X10 relay switches in the house to turn on lights remotely. This would obviate my walking across the room in the dark to get to the light switch.

Problem: The X10 switch/relay requires full power at the wall switch location. Several of my switches have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral wire into the box.

They make a motion sensor wall switch that works off only the hot leg
in the switchbox. You can try that as an alternative.

On Thu, 15 Sep 2011 22:55:39 -0700 (PDT), Ivan Vegvary
wrote:

Want to install several X10 relay switches in the house to turn on lights remotely. This would obviate my walking across the room in the dark to get to the light switch.

Problem: The X10 switch/relay requires full power at the wall switch location. Several of my switches have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral wire into the box.
Question: Most of my wiring is within the attic and some of the switches are on the exterior walls. These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo providing mere inches of crawl space. It would be much easier to run the neutral wire from below (I have a generous 42" high crawl space).
Question: Does this neutral have to come from the same circuit? Can I simply come from any circuit (even a separate new circuit) and run a white neutral wire to each switch box? Does it have to be from the same phase? X10 docs. do mention that if not from the same phase, then the phases can be joined at the box.

All comments, advice and suggestions appreciated.

Ivan Vegvary


It will work if you connect any neutral, but don't do it and here's
why: Suppose you are doing some remodeling or repairs down the road.
You kill the breaker to a circuit, check with your meter to make sure
the circuit is dead and start unwiring the circuit to replace a bad
outlet say. You disconnect the neutral, and all of a sudden it's hot
because upstream somewhere you connected your X10 from a different hot
circuit to the neutral of the one that you turned off. When you break
the neutral, the X10 provides a path to the other hot leg, and the
disconnected neutral becomes hot. Yes, it's current limited by the x10
and wouldn't power a toaster say, but there's more than enough current
available to make *you* toast.

This exact situation (doorbell xfmr, not x10) happened to me and I got
a good shock. It's especially dangerous because you can check the
circuit with a meter all you want before you break the neutral, and it
won't show that it's hot (because it's not, at that time). This is
why I always treat the neutrals as hot until they are disconnected and
verified to be dead.

So bite the bullet and do this some other way. And it is against
code, if you need another reason.

HTH,

Paul F.

On 9/16/2011 1:55 AM, Ivan Vegvary wrote:
Want to install several X10 relay switches in the house to turn on lights remotely. This would obviate my walking across the room in the dark to get to the light switch.

Problem: The X10 switch/relay requires full power at the wall switch location. Several of my switches have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral wire into the box.
Question: Most of my wiring is within the attic and some of the switches are on the exterior walls. These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo providing mere inches of crawl space. It would be much easier to run the neutral wire from below (I have a generous 42" high crawl space).
Question: Does this neutral have to come from the same circuit? Can I simply come from any circuit (even a separate new circuit) and run a white neutral wire to each switch box? Does it have to be from the same phase? X10 docs. do mention that if not from the same phase, then the phases can be joined at the box.

All comments, advice and suggestions appreciated.

Ivan Vegvary

I'm curious as to the wording X10 uses. It is a code violation and
potentially dangerous. There is a company that makes a wireless,
batteryless, wall switch receiver - transmitter kit. The wall switch
looks identical to a Decora switch, and can even be ganged with other
switches. The receiver module is small and will fit in most fixture
canopies. I've used them, they work great, the only issue is that the
set costs around $200. The company is called Enocean

On 9/16/2011 1:55 AM, Ivan Vegvary wrote:
Want to install several X10 relay switches in the house to turn on lights remotely. This would obviate my walking across the room in the dark to get to the light switch.

Problem: The X10 switch/relay requires full power at the wall switch location. Several of my switches
have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral
wire into the box.

That's a Code violation. *All* conductors are required to be in the same
raceway, conduit, or cable.

Question: Most of my wiring is within the attic and some of the switches are on the exterior walls.
These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo
providing mere inches of crawl space. It would be much easier to run the neutral wire from below
(I have a generous 42" high crawl space).

Then run an entirely new cable.

Question: Does this neutral have to come from the same circuit?

Yes.

Can I simply come from any circuit (even a separate new circuit) and run a white neutral wire
to each switch box?

No.

Does it have to be from the same phase? X10 docs. do mention that if not from the same phase,
then the phases can be joined at the box.

That's not a meaningful concept with respect to the neutral.

All comments, advice and suggestions appreciated.

No disrespect intended, but you should hire an electrician to do this
for you. You don't appear to have sufficient knowledge to do this safely.

On 9/16/2011 6:01 AM, Andy wrote:

The neutral (white) wire is not phase sensitive, so it can come
from
anywhere. However, it will NOT meet code, if that is a concern...

It's not just a question of whether it meets Code or not. This is also a
safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor.
When two circuits are cross-connected to use the same neutral, the
current in the neutral is the *sum* of the currents in the two hot legs.
A current of 15 amps in each of two hot legs will result in a 30A
current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

On Sep 16, 10:03*am, Marilyn & Bob wrote:
On 9/16/2011 9:46 AM, Marilyn & Bob wrote:





On 9/16/2011 7:45 AM, wrote:
On Sep 16, 7:10 am, Doug
wrote:
On 9/16/2011 1:55 AM, Ivan Vegvary wrote:

Want to install several X10 relay switches in the house to turn on
lights remotely. This would obviate my walking across the room in
the dark to get to the light switch.

Problem: The X10 switch/relay requires full power at the wall switch
location. Several of my switches
have only a hot leg coming into the box with no neutral. X10 docs.
recommend simply running a neutral
wire into the box.

That's a Code violation. *All* conductors are required to be in the same
raceway, conduit, or cable.

Question: Most of my wiring is within the attic and some of the
switches are on the exterior walls.
These locations are inaccessible from the attic since this is where
the roof meets the ceiling ergo
providing mere inches of crawl space. It would be much easier to run
the neutral wire from below
(I have a generous 42" high crawl space).

Then run an entirely new cable.

Question: Does this neutral have to come from the same circuit?

Yes.

Can I simply come from any circuit (even a separate new circuit) and
run a white neutral wire
to each switch box?

No.

Does it have to be from the same phase? X10 docs. do mention that if
not from the same phase,
then the phases can be joined at the box.

That's not a meaningful concept with respect to the neutral.

All comments, advice and suggestions appreciated.

No disrespect intended, but you should hire an electrician to do this
for you. You don't appear to have sufficient knowledge to do this
safely.

One possible solution is to use one of the X10 light switches
that don't use a neutral. They only work with incandescent
bulbs, but since he only mentions controlling lights that would
seem to be at least a possibility that would save a hell of a
lot of work.

The basic X-10 wall switch (WS467) does NOT require a neutral in order
to function. Its major problem is that it won't work with CFLs. However,
if you are concerned about energy consumption, it WILL work with LED
bulbs. While LED bulbs are quite expensive, they are a lot cheaper than
rewiring and require zero effort. And you'll save the money back since
WS467 switches are a lot cheaper than the CFL capable ones that require
the neutral. This seems to me to be the simplest, safe way to proceed.

Just checked the X-10 site and see that their new incandescent only wall
switches DO require a neutral, however the hot wire only switches that I
mentioned (WS467) are still available on Ebay.
--
Peace,
bobJ- Hide quoted text -

- Show quoted text -

The other issue with all things X10 is reliability. Since he's
apparently
just looking to control some lights across the room the reliability
will
probably be acceptable. Meaning if once in a while it doesn't respond
to a command he can just resend it. But for anyone considering
rewiring to support X10, they should know it's not 100% reliable and
may not suit the application.

Thanks M & B
I will order the WS467 switches through ebay. Incandescent bulbs are fine with me.

Should I choose to upgrade to a system that needs a neutral feed, I will run a full cable (circuit) from the service entrance to the switch box. The many safety concerns and code violations posted above are taken to heart.

Thanks everybody,

Ivan Vegvary

On Sep 16, 6:15 am, Doug Miller
wrote:

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Andy comments:
I am confused as to how you think someone could receive a shock
from the "neutral" wire... It is normally not disconnected in any
configuration --- only the black (red) hot lead.... All neutrals are
connected together, without interruption or disconnects, in the
panel... Except for current carrying capability, they are the same
wire....

In Ivan's use, the additional current, if any, carried by the
neutral
is very very very low --- certainly less than an ampere, and would not
screw up anything.... He just wants to put in a simple relay
module....

Other than that, you are correct, and it's only necessary to
let Ivan know of the risk... Personally, rather than rip out a wall
to rewire an outlet, I'd probably do it...

Mikepier's idea of a motion sensor that works on just
the hot line sounds good to me, too...

However, if there is room in the fixture for the light (or
whatever)
I'd just put the module in there, since black/white/copper will be
present anyway....

Andy in Eureka, Texas P.E.

On 9/16/2011 6:43 PM, Andy wrote:
On Sep 16, 6:15 am, Doug
wrote:

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Andy comments:
I am confused as to how you think someone could receive a shock
from the "neutral" wire...

Because it carries current. The same current that's in the hot.

It is normally not disconnected in any
configuration ---

It doesn't really matter whether it's disconnected or not. It's carrying
current.

Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

On Fri, 16 Sep 2011 06:41:00 -0400, Paul Franklin
wrote:

On Thu, 15 Sep 2011 22:55:39 -0700 (PDT), Ivan Vegvary
wrote:

Want to install several X10 relay switches in the house to turn on lights remotely. This would obviate my walking across the room in the dark to get to the light switch.

Problem: The X10 switch/relay requires full power at the wall switch location. Several of my switches have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral wire into the box.
Question: Most of my wiring is within the attic and some of the switches are on the exterior walls. These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo providing mere inches of crawl space. It would be much easier to run the neutral wire from below (I have a generous 42" high crawl space).
Question: Does this neutral have to come from the same circuit? Can I simply come from any circuit (even a separate new circuit) and run a white neutral wire to each switch box? Does it have to be from the same phase? X10 docs. do mention that if not from the same phase, then the phases can be joined at the box.

All comments, advice and suggestions appreciated.

Ivan Vegvary


It will work if you connect any neutral, but don't do it and here's
why: Suppose you are doing some remodeling or repairs down the road.
You kill the breaker to a circuit, check with your meter to make sure
the circuit is dead and start unwiring the circuit to replace a bad
outlet say. You disconnect the neutral, and all of a sudden it's hot
because upstream somewhere you connected your X10 from a different hot
circuit to the neutral of the one that you turned off. When you break
the neutral, the X10 provides a path to the other hot leg, and the
disconnected neutral becomes hot. Yes, it's current limited by the x10
and wouldn't power a toaster say, but there's more than enough current
available to make *you* toast.

This exact situation (doorbell xfmr, not x10) happened to me and I got
a good shock. It's especially dangerous because you can check the
circuit with a meter all you want before you break the neutral, and it
won't show that it's hot (because it's not, at that time). This is
why I always treat the neutrals as hot until they are disconnected and
verified to be dead.

So bite the bullet and do this some other way. And it is against
code, if you need another reason.

HTH,

Paul F.
Can you say "red herring" or "straw man"?

When you shutt of a breaker you ONLY shut off the "line" - not the
neutral.

When you go to replace that theoretical outlet, the neutral is STILL
GROUNDED at the panel - so there is NO voltage differential between it
and ground. Also, the X10 is not a load, like a bell transformer. It
is a voltage controlled device - not current - so it is only
"injecting" a couple of milliamps into the neutral - so even IF it was
ungrounded at the panel (which would make the circuit totally
inoperative) it would be doing good to give you a little tickle -
muchless harm you.

On Fri, 16 Sep 2011 07:15:33 -0400, Doug Miller
wrote:

On 9/16/2011 6:01 AM, Andy wrote:

The neutral (white) wire is not phase sensitive, so it can come
from
anywhere. However, it will NOT meet code, if that is a concern...

It's not just a question of whether it meets Code or not. This is also a
safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor.
When two circuits are cross-connected to use the same neutral, the
current in the neutral is the *sum* of the currents in the two hot legs.
A current of 15 amps in each of two hot legs will result in a 30A
current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?
It is illegal - but in the case he's speeking of, NOT necessarily
dangerous. The neutral is only required to activate the x10 switch. It
is NOT a load neutral 3 connections on the X10 device' Line in , Line
out, and neutral. The neutral is only used by the control circuit -
which is a voltage controlled switch - not current controlled (think
j-fet vs bipolar transistor) -

On Fri, 16 Sep 2011 09:46:55 -0400, Marilyn & Bob
wrote:

On 9/16/2011 7:45 AM, wrote:
On Sep 16, 7:10 am, Doug
wrote:
On 9/16/2011 1:55 AM, Ivan Vegvary wrote:

Want to install several X10 relay switches in the house to turn on lights remotely. This would obviate my walking across the room in the dark to get to the light switch.

Problem: The X10 switch/relay requires full power at the wall switch location. Several of my switches
have only a hot leg coming into the box with no neutral. X10 docs. recommend simply running a neutral
wire into the box.

That's a Code violation. *All* conductors are required to be in the same
raceway, conduit, or cable.

Question: Most of my wiring is within the attic and some of the switches are on the exterior walls.
These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo
providing mere inches of crawl space. It would be much easier to run the neutral wire from below
(I have a generous 42" high crawl space).

Then run an entirely new cable.

Question: Does this neutral have to come from the same circuit?

Yes.

Can I simply come from any circuit (even a separate new circuit) and run a white neutral wire
to each switch box?

No.

Does it have to be from the same phase? X10 docs. do mention that if not from the same phase,
then the phases can be joined at the box.

That's not a meaningful concept with respect to the neutral.



All comments, advice and suggestions appreciated.

No disrespect intended, but you should hire an electrician to do this
for you. You don't appear to have sufficient knowledge to do this safely.

One possible solution is to use one of the X10 light switches
that don't use a neutral. They only work with incandescent
bulbs, but since he only mentions controlling lights that would
seem to be at least a possibility that would save a hell of a
lot of work.

The basic X-10 wall switch (WS467) does NOT require a neutral in order
to function. Its major problem is that it won't work with CFLs.
However, if you are concerned about energy consumption, it WILL work
with LED bulbs. While LED bulbs are quite expensive, they are a lot
cheaper than rewiring and require zero effort. And you'll save the
money back since WS467 switches are a lot cheaper than the CFL capable
ones that require the neutral. This seems to me to be the simplest,
safe way to proceed.
Or throw a single 7 watt ( or higher)incandescent bulb in the circuit
with as many CFLs as you want.

Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Huh?

The reason you don't use the "wrong" neutral is just the subtle effect
of poor cancellation of the magnetic field generated by current carrying
conductors. If the conductor and it's neutral are close to each other
their magnetic fields cancel.

The main time neutrals can produce a dangerous situation is when,
somehow, they get dis-connected from the power source (either at the
service/breaker panel or in an intermediate junction box.) Any kind of
a load will make a white wire (your neutral, HOT, HOT, HOT!

On Sep 16, 11:02*pm, John Gilmer wrote:
Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Huh?

The reason you don't use the "wrong" neutral is just the subtle effect
of poor cancellation of the magnetic field generated by current carrying
conductors. * If the conductor and it's neutral are close to each other
their magnetic fields cancel.

No. As has been explained to you there are two very
real problems with using the neutral from another circuit
and why it's a serious code violation.

1 - As Doug explained above, when doing a repair, you
shut off the breaker to circuit A. If that neutral on that
circuit belongs only to it, then you can't get a shock.
If on the other hand the neutral is actually connected
to circuit B which is still energized and has an active
load, then current is flowing in that neutral. Exactly
what your chances of getting shocked are will vary
depending on how it's wired.

Worst case, consider
that the neutral arrives in the wall box you happen
to be working on. It comes from the other energized
circuit's load, into a wirenut that is pigtailed to the
switch. Also connected to the wirenut is the
neutral wire going back to the panel. You take off
the wire nut. Now you have 120V on the neutral
coming from the other circuit in your hand.
If you happen to be grounded, you complete
the circuit.

Best case is you just tap off another neutral
and the neutral just ends where you're using it.
Even then as Doug pointed out, current divides
depending on resistance. Grab that wire while
you're grounded to something and some current
will flow through you as you are now an alternate
path back to the panel.

2 - Conductors are sized for the circuit they are
serving and for the corresponding breaker. By
sharing a neutral, you could put not only the
current from circuit A through it, but also the
current from circuit B, exceeding the safe
current for that conductor by 2X or even more.




The main time neutrals can produce a dangerous situation is when,
somehow, they get dis-connected from the power source (either at the
service/breaker panel or in an intermediate junction box.) * Any kind of
a load will make a white wire (your neutral, HOT, HOT, HOT!

Which would include the poor guy who turns off breaker A
then disconnects the neutral, not knowing that the neutral
is actually connected to circuit B.

On 9/16/2011 8:42 PM, wrote:
On Fri, 16 Sep 2011 07:15:33 -0400, Doug Miller
wrote:

On 9/16/2011 6:01 AM, Andy wrote:

The neutral (white) wire is not phase sensitive, so it can come
from
anywhere. However, it will NOT meet code, if that is a concern...

It's not just a question of whether it meets Code or not. This is also a
safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor.
When two circuits are cross-connected to use the same neutral, the
current in the neutral is the *sum* of the currents in the two hot legs.
A current of 15 amps in each of two hot legs will result in a 30A
current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?
It is illegal - but in the case he's speeking of, NOT necessarily
dangerous. The neutral is only required to activate the x10 switch. It
is NOT a load neutral 3 connections on the X10 device' Line in , Line
out, and neutral. The neutral is only used by the control circuit -
which is a voltage controlled switch - not current controlled (think
j-fet vs bipolar transistor) -

Yes, it is necessarily dangerous. We're discussing specifically pulling
a neutral from *another circuit*. The current in the neutral will be
whatever currrent is drawn by the load operating on the *other* circuit,
not the current in the X10 device.

On 9/16/2011 11:02 PM, John Gilmer wrote:


Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Huh?

The reason you don't use the "wrong" neutral is just the subtle effect
of poor cancellation of the magnetic field generated by current carrying
conductors. If the conductor and it's neutral are close to each other
their magnetic fields cancel.

I know that. But that's completely unrelated to the shock danger.

You *can* get shocked by the neutral.

The main time neutrals can produce a dangerous situation is when,
somehow, they get dis-connected from the power source

Even if the neutral is not disconnected, if you make, with your body, a
parallel conductive path from the neutral to ground, *most* of the
current in that neutral will indeed return to ground through the neutral
conductor -- but *some* of it will return through your body, as well.

Electricity follows *all possible paths*. Don't use your body as one of
them.

(either at the
service/breaker panel or in an intermediate junction box.) Any kind of a
load will make a white wire (your neutral, HOT, HOT, HOT!

And that makes your body the *only* path for the current to flow
through. Your mistake is in thinking that this is the only dangerous
condition. It's not.

On Sep 16, 8:42*pm, wrote:
On Fri, 16 Sep 2011 07:15:33 -0400, Doug Miller





wrote:
On 9/16/2011 6:01 AM, Andy wrote:

* *The neutral (white) wire is not phase sensitive, so it can come
from
anywhere. * However, it will NOT meet code, if that is a concern...

It's not just a question of whether it meets Code or not. This is also a
safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor.
When two circuits are cross-connected to use the same neutral, the
current in the neutral is the *sum* of the currents in the two hot legs.
A current of 15 amps in each of two hot legs will result in a 30A
current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

* It is illegal - but in the case he's speeking of, NOT necessarily
dangerous. The neutral is only required to activate the x10 switch. It
is NOT a load neutral *3 connections on the X10 device' Line in , Line
out, and neutral. The neutral is only used by the control circuit -
which is a voltage controlled switch - not current controlled (think
j-fet vs bipolar transistor) -- Hide quoted text -

- Show quoted text -

That switch itself is in fact a load. A very small one, but it's
still a load. If it did not pass current on the neutral, then it
would not need the neutral. Could it deliver a serious shock
as is? I would agree that it would not, provided everything
else is wired correctly, meaning there is no disconnected
neutral on the other circuit, etc. But it could cause future
problems where someone later comes along and sees
that neutral, assumes it is on the same ciruit as the hot
and decides they want to use it for something
else, like adding more outlets, causing an overload.
That is the serious risk you run when you decide to
ignore a code rule that is universally followed by
almost everyone.

On Sep 16, 6:29 pm, Doug Miller
wrote:
On 9/16/2011 6:43 PM, Andy wrote:

On Sep 16, 6:15 am, Doug
wrote:

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Andy comments:
I am confused as to how you think someone could receive a shock
from the "neutral" wire...

Because it carries current. The same current that's in the hot.

It is normally not disconnected in any
configuration ---

It doesn't really matter whether it's disconnected or not. It's carrying
current.

Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Andy comments:

You are incorrect. I suggest you actually try it. Both neutrals
are
connected together, HARDWIRED, at the sub panel... You are no
more likely to get a shock from one as from the other...

But, I'm not here to argue with you... My input is to Ivan... He
is
smart enough to read all the inputs and decide for himself...

Andy in Eureka, Texas, Licensed Electrical
Engineer....

On Sep 16, 10:02 pm, John Gilmer wrote:
Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Huh?

The reason you don't use the "wrong" neutral is just the subtle effect
of poor cancellation of the magnetic field generated by current carrying
conductors. If the conductor and it's neutral are close to each other
their magnetic fields cancel.

The main time neutrals can produce a dangerous situation is when,
somehow, they get dis-connected from the power source (either at the
service/breaker panel or in an intermediate junction box.) Any kind of
a load will make a white wire (your neutral, HOT, HOT, HOT!

Andy writes:
Absolutely correct, and this "dangerous situation" is not part
of
Ivan's problem.....Although I would suggest that he, like EVERYONE,
should check his panel every couple of years to make sure all the
little white wires are screwed in securely to the neutral bar ......
...... and also the little bare copper wires... just for safety....

Andy in Eureka, Texas

On Sep 17, 9:33*am, Andy wrote:
On Sep 16, 6:29 pm, Doug Miller
wrote:





On 9/16/2011 6:43 PM, Andy wrote:

On Sep 16, 6:15 am, Doug
wrote:

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Andy comments:
* *I am confused as to how you think someone could receive a shock
from the "neutral" wire...

Because it carries current. The same current that's in the hot.

It is normally not disconnected in any
configuration ---

It doesn't really matter whether it's disconnected or not. It's carrying
current.

Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Andy comments:

* You are incorrect. *I suggest you actually try it. * Both neutrals
are
connected together, HARDWIRED, at the sub panel... You are no
more likely to get a shock from one as from the other...

* *But, I'm not here to argue with you... My input *is to Ivan... He
is
smart enough to read all the inputs and decide for himself...

* * * * * * * * * * Andy in Eureka, Texas, *Licensed Electrical
Engineer....- Hide quoted text -

- Show quoted text -

They are in fact wired together and I see your reasoning.
Now consider this. The hardwired together theory works if
there is no resistance in the netural wires all the way
back to the panel. In the real word there is some resistance
in the neutral wire of the second energized circuit along
the way. Resistance of the wire, any connection points,
eg wire nuts, etc. Now if the second circuit is energized
and carrying 15 amps, there will in fact be some small
voltage potential there relative to ground. So, it's not
the same as the neutral for the disconnected circuit.
It's not likely to be enough to shock you, but that is
provided EVERYTHING ELSE IS WIRED AND WORKING
PROPERLY ON THE OTHER CIRCUIT.

And leaving that neutral there opens up the possibility
that someone else will come along someday, see
it, and decide to tap on to that circuit for something
else, eg new outlets, loads, etc. Now you have
a conductor inadequate for the overload protection.
It also screws up GFCI protection, whether now or
in the future.

I'm surprised that an EE woudl in essence give
an OK to what most of us consider a serious
code violation.

On Sep 17, 8:44 am, "
wrote:
On Sep 17, 9:33 am, Andy wrote:



On Sep 16, 6:29 pm, Doug Miller
wrote:

On 9/16/2011 6:43 PM, Andy wrote:

On Sep 16, 6:15 am, Doug
wrote:

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Andy comments:
I am confused as to how you think someone could receive a shock
from the "neutral" wire...

Because it carries current. The same current that's in the hot.

It is normally not disconnected in any
configuration ---

It doesn't really matter whether it's disconnected or not. It's carrying
current.

Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Andy comments:

You are incorrect. I suggest you actually try it. Both neutrals
are
connected together, HARDWIRED, at the sub panel... You are no
more likely to get a shock from one as from the other...

But, I'm not here to argue with you... My input is to Ivan... He
is
smart enough to read all the inputs and decide for himself...

Andy in Eureka, Texas, Licensed Electrical
Engineer....- Hide quoted text -

- Show quoted text -

They are in fact wired together and I see your reasoning.
Now consider this. The hardwired together theory works if
there is no resistance in the netural wires all the way
back to the panel. In the real word there is some resistance
in the neutral wire of the second energized circuit along
the way. Resistance of the wire, any connection points,
eg wire nuts, etc. Now if the second circuit is energized
and carrying 15 amps, there will in fact be some small
voltage potential there relative to ground. So, it's not
the same as the neutral for the disconnected circuit.
It's not likely to be enough to shock you, but that is
provided EVERYTHING ELSE IS WIRED AND WORKING
PROPERLY ON THE OTHER CIRCUIT.

And leaving that neutral there opens up the possibility
that someone else will come along someday, see
it, and decide to tap on to that circuit for something
else, eg new outlets, loads, etc. Now you have
a conductor inadequate for the overload protection.
It also screws up GFCI protection, whether now or
in the future.

I'm surprised that an EE woudl in essence give
an OK to what most of us consider a serious
code violation.

Andy comments:

I can surprise you as much as you like...

I agree with your hypothetical situation.... Ivan is aware of it
now, and can make up his own mind about the risk....

Why not confine your advice to Ivan, rather than trying to
do a "'one-upsmanship" jihad on other posters , although
it seems to be a "natural" for you ... ??????

Andy in Eureka, Texas

On Sep 16, 7:42 pm, wrote:

It is illegal - but in the case he's speeking of, NOT necessarily
dangerous. The neutral is only required to activate the x10 switch. It
is NOT a load neutral 3 connections on the X10 device' Line in , Line
out, and neutral. The neutral is only used by the control circuit -
which is a voltage controlled switch - not current controlled (think
j-fet vs bipolar transistor) -



Andy comments:
Exactly. Now that Ivan has seen the problem from several angles,
l think he can make an informed decision about what he wants to do...

Still, I HEARTILY reccommend him putting the X10 module in the
fixture where it is used, rather than the wall switch..... if he has
room...
All the other arguments should be considered, but the convenience
of a low current #14 white wire for
one simple circuit may be the overriding factor......I am sure that a
future electrician will see immediately that a non-standard method
has been used and will re-think his options...

Andy in Eureka, Texas

PS Ivan, maybe you can do a search for a battery operated control
module.... one that can replace the wall switch but has a couple
of AA cells in it for the controller activation.... I haven't
seen one,
but I haven't looked, either...

In article ,
Doug Miller wrote:

On 9/16/2011 6:01 AM, Andy wrote:

The neutral (white) wire is not phase sensitive, so it can come
from
anywhere. However, it will NOT meet code, if that is a concern...

It's not just a question of whether it meets Code or not. This is also a
safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor.
When two circuits are cross-connected to use the same neutral, the
current in the neutral is the *sum* of the currents in the two hot legs.
A current of 15 amps in each of two hot legs will result in a 30A
current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Would a multi wire branch circuit meet code and be safe?

On Sep 16, 8:37*pm, wrote:
On Fri, 16 Sep 2011 06:41:00 -0400, Paul Franklin









wrote:
On Thu, 15 Sep 2011 22:55:39 -0700 (PDT), Ivan Vegvary
wrote:

Want to install several X10 relay switches in the house to turn on lights remotely. *This would obviate my walking across the room in the dark to get to the light switch.

Problem: *The X10 switch/relay requires full power at the wall switch location. *Several of my switches have only a hot leg coming into the box with no neutral. *X10 docs. recommend simply running a neutral wire into the box. *
Question: *Most of my wiring is within the attic and some of the switches are on the exterior walls. *These locations are inaccessible from the attic since this is where the roof meets the ceiling ergo providing mere inches of crawl space. *It would be much easier to run the neutral wire from below (I have a generous 42" high crawl space). *
Question: *Does this neutral have to come from the same circuit? *Can I simply come from any circuit (even a separate new circuit) and run a white neutral wire to each switch box? *Does it have to be from the same phase? *X10 docs. do mention that if not from the same phase, then the phases can be joined at the box.

All comments, advice and suggestions appreciated.

Ivan Vegvary

It will work if you connect any neutral, but don't do it and here's
why: *Suppose you are doing some remodeling or repairs down the road.
You kill the breaker to a circuit, check with your meter to make sure
the circuit is dead and start unwiring the circuit to replace a bad
outlet say. *You disconnect the neutral, and all of a sudden it's hot
because upstream somewhere you connected your X10 from a different hot
circuit to the neutral of the one that you turned off. *When you break
the neutral, the X10 provides a path to the other hot leg, and the
disconnected neutral becomes hot. Yes, it's current limited by the x10
and wouldn't power a toaster say, but there's more than enough current
available to make *you* toast.

This exact situation (doorbell xfmr, not x10) happened to me and I got
a good shock. *It's especially dangerous because you can check the
circuit with a meter all you want before you break the neutral, and it
won't show that it's hot (because it's not, at that time). *This is
why I always treat the neutrals as hot until they are disconnected and
verified to be dead.

So bite the bullet and do this some other way. *And it is against
code, if you need another reason.

HTH,

Paul F.

*Can you say "red herring" or "straw man"?

When you shutt of a breaker you ONLY shut off the "line" - not the
neutral.

When you go to replace that theoretical outlet, the neutral is STILL
GROUNDED at the panel - so there is NO voltage differential between it
and ground. Also, the X10 is not a load, like a bell transformer. It
is a voltage controlled device - not current - so it is only
"injecting" a couple of milliamps into the neutral - so even IF it was
ungrounded at the panel (which would make the circuit totally
inoperative) it would be doing good to give you a little tickle -
muchless harm you.

There not talking about the current, if any, from the X10 device.
They are talking about the current from other loads on the circuit
that the neutral is bootlegged from. If, in replacing the X10 device
at some future point in time, the splice in the neutral of the circuit
from which the bootlegged neutral was taken were opened the load side
of that splice will go high to one hundred twenty volts.

I had such an incident with a bootlegged neutral serving a lighting
fixture. I opened the switch to the light and installed a lock out
device on it. I checked for other hot circuits in the box with a
voltage proximity detector and got no voltage indication. I opened
the splice to the neutral, using best practice non contact technique,
and got a spark when I actually broke the neutral continuity. So I
checked again with the proximity detector and got a voltage
indication. I pulled out my Wiggy and got one hundred plus volts to
ground. I applied a tracer transmitter between the two disconnected
neutrals and it came on and produced a signal. When I opened the fuse
it led me to the voltage and the signal went away. I then reapplied
the power by closing the fuse and traced the neutral to discover were
it actually came from. I was able to rework the circuits arrangement
to clear the inter-circuit connection but, had I not used best
practice technique, I might have received a fatal shock.
--
Tom Horne

On Sep 17, 9:50*am, Andy wrote:
On Sep 17, 8:44 am, "
wrote:





On Sep 17, 9:33 am, Andy wrote:

On Sep 16, 6:29 pm, Doug Miller
wrote:

On 9/16/2011 6:43 PM, Andy wrote:

On Sep 16, 6:15 am, Doug
wrote:

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Andy comments:
* *I am confused as to how you think someone could receive a shock
from the "neutral" wire...

Because it carries current. The same current that's in the hot.

It is normally not disconnected in any
configuration ---

It doesn't really matter whether it's disconnected or not. It's carrying
current.

Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Andy comments:

* You are incorrect. *I suggest you actually try it. * Both neutrals
are
connected together, HARDWIRED, at the sub panel... You are no
more likely to get a shock from one as from the other...

* *But, I'm not here to argue with you... My input *is to Ivan.... He
is
smart enough to read all the inputs and decide for himself...

* * * * * * * * * * Andy in Eureka, Texas, *Licensed Electrical
Engineer....- Hide quoted text -

- Show quoted text -

They are in fact wired together and I see your reasoning.
Now consider this. *The hardwired together theory works if
there is no resistance in the netural wires all the way
back to the panel. *In the real word there is some resistance
in the neutral wire of the second energized circuit along
the way. *Resistance of the wire, any connection points,
eg wire nuts, etc. *Now if the second circuit is energized
and carrying 15 amps, there will in fact be some small
voltage potential there relative to ground. *So, it's not
the same as the neutral for the disconnected circuit.
It's not likely to be enough to shock you, but that is
provided EVERYTHING ELSE IS WIRED AND WORKING
PROPERLY ON THE OTHER CIRCUIT.

And leaving that neutral there opens up the possibility
that someone else will come along someday, see
it, and decide to tap on to that circuit for something
else, eg new outlets, loads, etc. * Now you have
a conductor inadequate for the overload protection.
It also screws up GFCI protection, *whether now or
in the future.

I'm surprised that an EE woudl in essence give
an OK to what most of us consider a serious
code violation.

Andy comments:

* *I can surprise you as much as you like...

I agree with your hypothetical situation.... *Ivan is aware of it
now, and can make up his own mind about the risk....

Why not confine your advice to Ivan, rather than trying to
do a "'one-upsmanship" *jihad on other posters , although
it seems to be a "natural" for you ... *??????

* * * * * * * * * * * * * Andy in Eureka, Texas- Hide quoted text -

- Show quoted text -

Why are my replies "one upmanship", but yours which
advocate practices that violate NEC basics just peachy keen?
You've been going back and forth with Doug, have you
not? How is that responding only to Ivan?

It's not up to Ivan or anyone else to decide what constitutes
acceptable risk. That's what the NEC is for and I'd say
they have a hell of a lot more experience in what is safe
than you do. And you're rapidly on your way to becoming
one of the village idiots.

On 9/17/2011 11:40 AM, Dean Hoffman wrote:
In ,
Doug wrote:

On 9/16/2011 6:01 AM, Andy wrote:

The neutral (white) wire is not phase sensitive, so it can come
from
anywhere. However, it will NOT meet code, if that is a concern...

It's not just a question of whether it meets Code or not. This is also a
safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor.
When two circuits are cross-connected to use the same neutral, the
current in the neutral is the *sum* of the currents in the two hot legs.
A current of 15 amps in each of two hot legs will result in a 30A
current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Would a multi wire branch circuit meet code and be safe?

Yes, as long as it is installed in compliance with the Code --
specifically, in reference to the OP's question, with all conductors
being in the same cable. A DP breaker will also be required.

On Sep 17, 9:58*am, Andy wrote:
On Sep 16, 7:42 pm, wrote:

* It is illegal - but in the case he's speeking of, NOT necessarily
dangerous. The neutral is only required to activate the x10 switch. It
is NOT a load neutral *3 connections on the X10 device' Line in , Line
out, and neutral. The neutral is only used by the control circuit -
which is a voltage controlled switch - not current controlled (think
j-fet vs bipolar transistor) -

Andy comments:
* *Exactly. *Now that Ivan has seen the problem from several angles,
l think he can make an informed decision about what he wants to do...

It's not up to Ivan to decide what's safe or unsafe. What makes
you think Ivan has the technial expertise to even understand
the issues involved? The NEC
serves the purpose of deciding what is safe and what you claim
is OK is a clear violation of NEC. Do you disagree with that?



* * *Still, I HEARTILY reccommend him putting the X10 module in the
fixture where it is used, rather than the wall switch..... if he has
room...
All the other arguments should be considered, but the convenience
of a low current #14 white wire for
one simple circuit may be the overriding factor......I am sure that a
future electrician will see immediately that a non-standard method
has been used and will re-think his options...

* * * * * * * * * * * *Andy in Eureka, Texas

A future electrician? Is Ivan an electrician? No, yet
he's doing the wiring. A future Ivan comes along and
expands the circuit using that neutral for other outlets.
Or maybe Ivan himself because either he doesn't
understand the real issues or 5 years from now
he forgets. Or Ivan goes to put in a GFCI on
that other circuit and can't figure out why it
constantly trips.

Convenience is never an excuse for violating the
NEC.






PS *Ivan, maybe you can do a search for a battery operated control
* * *module.... one that can replace the wall switch but has a couple
* * of AA cells in it for the controller activation.... * I haven't
seen one,
* * but I haven't looked, either...

Maybe you should look at the NEC first.

On 9/17/2011 9:33 AM, Andy wrote:
On Sep 16, 6:29 pm, Doug
wrote:
On 9/16/2011 6:43 PM, Andy wrote:

On Sep 16, 6:15 am, Doug
wrote:

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Andy comments:
I am confused as to how you think someone could receive a shock
from the "neutral" wire...

Because it carries current. The same current that's in the hot.

It is normally not disconnected in any
configuration ---

It doesn't really matter whether it's disconnected or not. It's carrying
current.

Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Andy comments:

You are incorrect. I suggest you actually try it. Both neutrals
are
connected together, HARDWIRED, at the sub panel...

Yes, I know that. You don't seem to understand the concept of parallel
circuits. If your body is grounded, and also in contact with the neutral
conductor, there are two parallel paths to ground: one through the
neutral conductor, and one through your body.

Most of the current will flow through the copper conductors. But it
takes only a few tens of milliamps to interfere with heart rhythms.

You are nomore likely to get a shock from one as from the other...

In the sense that you're equally able to get a shock from each, I'd agree.

But, I'm not here to argue with you... My input is to Ivan... He
is
smart enough to read all the inputs and decide for himself...

Andy in Eureka, Texas, Licensed Electrical
Engineer....

An EE that doesn't understand parallel circuits? Yeah, riiiiight.

On 9/17/2011 9:44 AM, wrote:

I'm surprised that an EE woudl in essence give
an OK to what most of us consider a serious
code violation.

It doesn't surprise me at all. Most of the EEs that I've met or talked
with don't understand a damn thing about residential electrical wiring.

On Sep 17, 12:04*pm, Doug Miller
wrote:
On 9/17/2011 9:44 AM, wrote:

I'm surprised that an EE woudl in essence give
an OK to what most of us consider a serious
code violation.

It doesn't surprise me at all. Most of the EEs that I've met or talked
with don't understand a damn thing about residential electrical wiring.

Along those lines, concerning practical wiring, the whole thing
is rather funny, don't you think? We have Andy desperately
trying to give Ivan an excuse to go tap in to another neutral.
But for what useful purpose?
You and I know that in almost all cases, if you can go find
another neutral, you can find the hot that goes with it. Last
time I checked, Romex comes with two conductors, so
what is achieved by running only the neutral
back, instead of both the hot and neutral and moving the
light entirely to the other circuit? Doing the latter makes
it code compliant, standard practice and is no more work.

Maybe Andy the EE can answer that for us.

On 9/17/2011 1:33 PM, wrote:
On Sep 17, 12:04 pm, Doug
wrote:
On 9/17/2011 9:44 AM, wrote:

I'm surprised that an EE woudl in essence give
an OK to what most of us consider a serious
code violation.

It doesn't surprise me at all. Most of the EEs that I've met or talked
with don't understand a damn thing about residential electrical wiring.

Along those lines, concerning practical wiring, the whole thing
is rather funny, don't you think?

Well, it would be, if it weren't for the potential hazards.

We have Andy desperately
trying to give Ivan an excuse to go tap in to another neutral.
But for what useful purpose?
You and I know that in almost all cases, if you can go find
another neutral, you can find the hot that goes with it. Last
time I checked, Romex comes with two conductors, so
what is achieved by running only the neutral
back, instead of both the hot and neutral and moving the
light entirely to the other circuit? Doing the latter makes
it code compliant, standard practice and is no more work.

Maybe Andy the EE can answer that for us.

Don't hold your breath...

On Sat, 17 Sep 2011 09:26:33 -0400, Doug Miller
wrote:

On 9/16/2011 8:42 PM, wrote:
On Fri, 16 Sep 2011 07:15:33 -0400, Doug Miller
wrote:

On 9/16/2011 6:01 AM, Andy wrote:

The neutral (white) wire is not phase sensitive, so it can come
from
anywhere. However, it will NOT meet code, if that is a concern...

It's not just a question of whether it meets Code or not. This is also a
safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor.
When two circuits are cross-connected to use the same neutral, the
current in the neutral is the *sum* of the currents in the two hot legs.
A current of 15 amps in each of two hot legs will result in a 30A
current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?
It is illegal - but in the case he's speeking of, NOT necessarily
dangerous. The neutral is only required to activate the x10 switch. It
is NOT a load neutral 3 connections on the X10 device' Line in , Line
out, and neutral. The neutral is only used by the control circuit -
which is a voltage controlled switch - not current controlled (think
j-fet vs bipolar transistor) -

Yes, it is necessarily dangerous. We're discussing specifically pulling
a neutral from *another circuit*. The current in the neutral will be
whatever currrent is drawn by the load operating on the *other* circuit,
not the current in the X10 device.
But there will be no voltage difference between neutral and ground -
so the neutral is still SAFE. ALL neutrals are the same potential =
zero volts to ground - unless the neutral is "lifted".

If you shut off the circuit the X10 is used on, the "other circuit"
neutral is still zero volts. So it is not an issue.

If you shut off the "other circuit" to work on IT, the neutral from
the x10 is not carrying any load - so although a sensitive voltmeter
MAY show a voltage, there will not be enough current to shock you. It
MAY give you a barely perceptible tingle. and then only, as I said
before, if the neutral is "lifted" - ie - the wire from the x10 is
separated from the circuit neutral, the circuit neutral is opened
somewhere between that connection and the neutral buss (ground) or the
neutral is disconnected from the buss.

So the chances that it would EVER be dangerous are extremely remote.
It is, however, still against code.

The reason it is against code is because, having the "off circuit"
neutral in the box with the live line, someone down the road COULD
connect a load to that neutral. As soon as a load is connected to that
neutral ALL of the situations everyone is worried about BECOME
possibilities.
The neutral just for the X10 device is NOT, in itself, a safety issue.

Again - I would NOT recommend it. It IS contrary to code (so you could
say it is illegal) - but it is not, necessarily, dangerous.

On Sat, 17 Sep 2011 09:30:34 -0400, Doug Miller
wrote:

On 9/16/2011 11:02 PM, John Gilmer wrote:


Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Huh?

The reason you don't use the "wrong" neutral is just the subtle effect
of poor cancellation of the magnetic field generated by current carrying
conductors. If the conductor and it's neutral are close to each other
their magnetic fields cancel.

I know that. But that's completely unrelated to the shock danger.

You *can* get shocked by the neutral.

The main time neutrals can produce a dangerous situation is when,
somehow, they get dis-connected from the power source

Even if the neutral is not disconnected, if you make, with your body, a
parallel conductive path from the neutral to ground, *most* of the
current in that neutral will indeed return to ground through the neutral
conductor -- but *some* of it will return through your body, as well.

Electricity follows *all possible paths*. Don't use your body as one of
them.

IF the neutral connection is "adequate" - less than 1/2 ohm, let's
just say for arguement's sake, and your body resistance is lower than
normal (let's just pick 500 ohms out of thin air) and the load current
is 15 amps (anything more would trip the supply side breaker) what
current would flow through your body???? The voltage drop across the
..5 ohm ground connection would be 7.5 (15 ampsX.5 ohms)volts. The
current through your 500 ohm body would be less than 15 ma.

A .5 ohm ground connection would show up as an obvious problem with a
7.5 volt drop and 112 watts of heat dissipation at the ground
connection. A much more common (or let's say POSSIBLE situation is a
..05 ohm ground connection - with a 0.75 volt drop, dissipating 11
watts of heat at the bad connection (still very noticeable as a bad
connection) where the current flow through a 500 ohm body resistance
would be less than 1.5 ma.

Now substitute a much more realistic body resistance (with wet skin)
of 10,000 ohms and you can see how rediculous your arguement is. 7.5
volts across a 10,000 ohm resistance is 0.75 ma of current.

Go to a DRY SKIN situation, with body resistance of 450,000 - 495,000
ohms, and you see where we are headed??????? We are aproching 1.5 e-5
amps. that's something like 0.0015ma if my exponential math is
correct. And that is with the VERY BAD 0.5 ohm ground.

(either at the
service/breaker panel or in an intermediate junction box.) Any kind of a
load will make a white wire (your neutral, HOT, HOT, HOT!

And that makes your body the *only* path for the current to flow
through. Your mistake is in thinking that this is the only dangerous
condition. It's not.

On Sat, 17 Sep 2011 06:32:50 -0700 (PDT), "
wrote:

On Sep 16, 8:42Â*pm, wrote:
On Fri, 16 Sep 2011 07:15:33 -0400, Doug Miller





wrote:
On 9/16/2011 6:01 AM, Andy wrote:

Â* Â*The neutral (white) wire is not phase sensitive, so it can come
from
anywhere. Â* However, it will NOT meet code, if that is a concern...

It's not just a question of whether it meets Code or not. This is also a
safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor.
When two circuits are cross-connected to use the same neutral, the
current in the neutral is the *sum* of the currents in the two hot legs.
A current of 15 amps in each of two hot legs will result in a 30A
current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Â* It is illegal - but in the case he's speeking of, NOT necessarily
dangerous. The neutral is only required to activate the x10 switch. It
is NOT a load neutral Â*3 connections on the X10 device' Line in , Line
out, and neutral. The neutral is only used by the control circuit -
which is a voltage controlled switch - not current controlled (think
j-fet vs bipolar transistor) -- Hide quoted text -

- Show quoted text -

That switch itself is in fact a load. A very small one, but it's
still a load. If it did not pass current on the neutral, then it
would not need the neutral. Could it deliver a serious shock
as is? I would agree that it would not, provided everything
else is wired correctly, meaning there is no disconnected
neutral on the other circuit, etc. But it could cause future
problems where someone later comes along and sees
that neutral, assumes it is on the same ciruit as the hot
and decides they want to use it for something
else, like adding more outlets, causing an overload.
That is the serious risk you run when you decide to
ignore a code rule that is universally followed by
almost everyone.
If, as I suspect, the switching mechanism in the X10 is a voltage
controlled switch (think FET or MOSFET device) there is NO current
flow to the neutral.

Howver, you HAVE identified the danger - the POSSIBLE FUTURE danger
which makes it illegal and unadviseable to use the "split neutral"
configuration. The FACT that the orphan neutral is in the box makes it
POSSIBLE for some future person (or even the OP, in the future) to use
that neutral to complete the circuit for a REAL load, such as an
aditional outlet or lamp. Since it is APPARENTLY possible to bring a
neutral up from below, the much better way to approach this is to
bring a FRESH CIRCUIT up from below to power this.

On 9/17/2011 7:45 PM, wrote:

But there will be no voltage difference between neutral and ground -

In an ideal world, perhaps. In the real world, where houses are not
wired with superconducting cable, copper wire has a very low but
definitely non-zero resistance. And splices in copper wire have a very
low but definitely non-zero resistance. And the potential difference
between the electrical system grounding electrode and the water pipe,
for example, that you're touching is not necessarily zero.

so the neutral is still SAFE.

NO IT'S NOT. The neutral carries current.

ALL neutrals are the same potential =
zero volts to ground - unless the neutral is "lifted".

That doesn't matter. If your body is also at ground potential, and you
contact the neutral, your body forms a parallel path for that current to
return to ground.

Granted, most of that current will be in the neutral conductor, and not
in your body -- but it doesn't take very much to kill you. Why do you
suppose the trip threshold on a GFCI is only 20mA?

If you shut off the circuit the X10 is used on, the "other circuit"
neutral is still zero volts. So it is not an issue.

Wrong again. If there is a load on the other circuit, there is current
flowing in the neutral wire. If you touch it while you are grounded, you
have formed a parallel path to ground for some of that current to return
through your body.

Worse, if you *open* a splice in that neutral, not knowing that it's
carrying current from some other circuit, you may have formed a parallel
path to ground for *all* of that current to return through your body.

If you shut off the "other circuit" to work on IT, the neutral from
the x10 is not carrying any load

Nobody ever claimed that the tiny current drawn by the X10 device
constituted a hazard of any sort.

So the chances that it would EVER be dangerous are extremely remote.
It is, however, still against code.

Right. It's against Code because ... wait for it ... it's DANGEROUS.

The reason it is against code is because, having the "off circuit"
neutral in the box with the live line, someone down the road COULD
connect a load to that neutral.

And that "someone down the road" could be as simple as someone turning
on an appliance in the kitchen while Ivan is installing his X10 gizmos.
I would not enjoy being part of the return path for the current drawn by
a toaster or microwave oven. YMMV.

As soon as a load is connected to that
neutral ALL of the situations everyone is worried about BECOME
possibilities.

Which is exactly what I've been saying all long -- that if there is a
load on the other circuit, the current in the neutral is a potential
hazard. Thank you for [finally] acknowledging that.

The neutral just for the X10 device is NOT, in itself, a safety issue.

Again - I would NOT recommend it. It IS contrary to code (so you could
say it is illegal) - but it is not, necessarily, dangerous.

Yes, it is. I hope that you don't ever learn the hard way that you're
mistaken.

On Sat, 17 Sep 2011 12:00:24 -0400, Doug Miller
wrote:

On 9/17/2011 9:33 AM, Andy wrote:
On Sep 16, 6:29 pm, Doug
wrote:
On 9/16/2011 6:43 PM, Andy wrote:

On Sep 16, 6:15 am, Doug
wrote:

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Andy comments:
I am confused as to how you think someone could receive a shock
from the "neutral" wire...

Because it carries current. The same current that's in the hot.

It is normally not disconnected in any
configuration ---

It doesn't really matter whether it's disconnected or not. It's carrying
current.

Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Andy comments:

You are incorrect. I suggest you actually try it. Both neutrals
are
connected together, HARDWIRED, at the sub panel...

Yes, I know that. You don't seem to understand the concept of parallel
circuits. If your body is grounded, and also in contact with the neutral
conductor, there are two parallel paths to ground: one through the
neutral conductor, and one through your body.

Most of the current will flow through the copper conductors. But it
takes only a few tens of milliamps to interfere with heart rhythms.

1ma is the threshold of sensory perception - less than 1ma the average
person can NOT detect. 5ma can be considered to be "dangerous"
20-30ma is a strong enough shock that you "can't let go" and at
anywhere between 100 and 300ma the heart is affected and death is
likely.
6 amps will stop the heart - after which normal rythm can be returned
(defibrilator)
That is current THROUGH THE BODY. If ALL of that current flows through
the HEART MUSCLE, several milliamps CAN be fatal.

You are nomore likely to get a shock from one as from the other...

In the sense that you're equally able to get a shock from each, I'd agree.

But, I'm not here to argue with you... My input is to Ivan... He
is
smart enough to read all the inputs and decide for himself...

Andy in Eureka, Texas, Licensed Electrical
Engineer....

An EE that doesn't understand parallel circuits? Yeah, riiiiight.

On Sep 17, 11:00 am, Doug Miller
wrote:
On 9/17/2011 9:33 AM, Andy wrote:



On Sep 16, 6:29 pm, Doug
wrote:
On 9/16/2011 6:43 PM, Andy wrote:

On Sep 16, 6:15 am, Doug
wrote:

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?

Andy comments:
I am confused as to how you think someone could receive a shock
from the "neutral" wire...

Because it carries current. The same current that's in the hot.

It is normally not disconnected in any
configuration ---

It doesn't really matter whether it's disconnected or not. It's carrying
current.

Consider two simple circuits, A and B, each supplying no loads other
than a single 100W light bulb, each of which is turned on -- but,
unbeknowst to you, their neutrals are cross-connected. Well and good.
Now suppose you need to replace the fixture on circuit A. Knowing that
it's on circuit A, you shut off that breaker, and disconnect the hot
lead to the fixture. Now when you go to disconnect the neutral lead, you
get a shock, because -- and I think this is the point you are missing --
electricity doesn't "follow the path of least resistance" as many people
believe, it follows *all possible paths*, including the one that you've
just made with your body by touching that energized lead.

Andy comments:

You are incorrect. I suggest you actually try it. Both neutrals
are
connected together, HARDWIRED, at the sub panel...

Yes, I know that. You don't seem to understand the concept of parallel
circuits. If your body is grounded, and also in contact with the neutral
conductor, there are two parallel paths to ground: one through the
neutral conductor, and one through your body.

Most of the current will flow through the copper conductors. But it
takes only a few tens of milliamps to interfere with heart rhythms.

You are nomore likely to get a shock from one as from the other...

In the sense that you're equally able to get a shock from each, I'd agree.



But, I'm not here to argue with you... My input is to Ivan... He
is
smart enough to read all the inputs and decide for himself...

Andy in Eureka, Texas, Licensed Electrical
Engineer....

An EE that doesn't understand parallel circuits? Yeah, riiiiight.

Andy comments:

You forget that the neutral circuit is connected to ground in
the panel. Nobody can get "shocked" by touching two separate white
wires, assuming they are connected together in the panel, where
they are also connected to the bare copper safety wiring, which
is also connected to the big metal rod which goes into the ground,
as well as the center conductor of the transformer on the pole
(or wherever), which also goes to a ground rod......etc....

Draw yourself a schematic , and you will understand.....

Andy in Eureka, Texas

On Sep 17, 6:45 pm, wrote:
On Sat, 17 Sep 2011 09:26:33 -0400, Doug Miller



wrote:
On 9/16/2011 8:42 PM, wrote:
On Fri, 16 Sep 2011 07:15:33 -0400, Doug Miller
wrote:

On 9/16/2011 6:01 AM, Andy wrote:

The neutral (white) wire is not phase sensitive, so it can come
from
anywhere. However, it will NOT meet code, if that is a concern...

It's not just a question of whether it meets Code or not. This is also a
safety issue. What you propose is dangerous:

The neutral conductor carries the same current as the hot conductor.
When two circuits are cross-connected to use the same neutral, the
current in the neutral is the *sum* of the currents in the two hot legs.
A current of 15 amps in each of two hot legs will result in a 30A
current in the neutral. This risks a fire.

Also, someone working on one circuit and not knowing that the neutral
carries current from a different circuit could receive a fatal shock
from that neutral -- how would he know to shut down both circuits?
It is illegal - but in the case he's speeking of, NOT necessarily
dangerous. The neutral is only required to activate the x10 switch. It
is NOT a load neutral 3 connections on the X10 device' Line in , Line
out, and neutral. The neutral is only used by the control circuit -
which is a voltage controlled switch - not current controlled (think
j-fet vs bipolar transistor) -

Yes, it is necessarily dangerous. We're discussing specifically pulling
a neutral from *another circuit*. The current in the neutral will be
whatever currrent is drawn by the load operating on the *other* circuit,
not the current in the X10 device.

But there will be no voltage difference between neutral and ground -
so the neutral is still SAFE. ALL neutrals are the same potential =
zero volts to ground - unless the neutral is "lifted".

If you shut off the circuit the X10 is used on, the "other circuit"
neutral is still zero volts. So it is not an issue.

If you shut off the "other circuit" to work on IT, the neutral from
the x10 is not carrying any load - so although a sensitive voltmeter
MAY show a voltage, there will not be enough current to shock you. It
MAY give you a barely perceptible tingle. and then only, as I said
before, if the neutral is "lifted" - ie - the wire from the x10 is
separated from the circuit neutral, the circuit neutral is opened
somewhere between that connection and the neutral buss (ground) or the
neutral is disconnected from the buss.

So the chances that it would EVER be dangerous are extremely remote.
It is, however, still against code.

The reason it is against code is because, having the "off circuit"
neutral in the box with the live line, someone down the road COULD
connect a load to that neutral. As soon as a load is connected to that
neutral ALL of the situations everyone is worried about BECOME
possibilities.
The neutral just for the X10 device is NOT, in itself, a safety issue.

Again - I would NOT recommend it. It IS contrary to code (so you could
say it is illegal) - but it is not, necessarily, dangerous.

Andy comments

Well stated....

Andy in Eureka, Texas