On Sun, 23 Apr 2006 02:32:07 GMT, m II wrote:
David wrote:
On Sat, 22 Apr 2006 03:10:50 GMT, Telamon
wrote:
In the USA at least the black wire is the hot wire with gold contacts
on connectors, white wire is the return with silver colored contacts
and green is the ground. Often the screw to put the ground wire on is
painted green or marked in a obvious way. Wall sockets and power cords
to appliances are all polarized to maintain this relationship of hot,
return and earth ground.
Neutral?
The white in a normal 120V receptacle is an identified, grounded(1)
conductor. A white in a 120/240V outlet such as an electric dryer, is a
neutral. It carries any unbalanced load between the two hots.
All neutrals are identified, grounded conductors, but not all
identified, grounded conductors are neutrals.
(1) not to be confused with a groundING conductor.
According to the terminology in the CEC and NEC, the
"grounding" conductor is for the safety ground, i.e., the
green
or bare or green with a yellow stripe wire. The word
"neutral"
is reserved for the white when you have a circuit with more
than
one "hot" wire. Since the white wire is connected to neutral
and
the grounding conductor inside the panel, the proper term is
"grounded conductor". However, the potential confusion
between
"grounded conductor" and "grounding conductor" can lead to
potentially lethal mistakes - you should never use the bare
wire
as a "grounded conductor" or white wire as the "grounding
conductor",
even though they are connected together in the panel.
[But not in subpanels - subpanels are fed neutral and ground
separately from the main panel. Usually.]
Note: do not tape, colour or substitute other colour wires for
the
safety grounding conductor.
In the trade, and in common usage, the word "neutral" is used
for "grounded conductor". This FAQ uses "neutral" simply to
avoid potential confusion. We recommend that you use
"neutral"
too. Thus the white wire is always (except in some light
switch applications) neutral. Not ground.
http://www.faqs.org/faqs/electrical-...ection-17.html