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