On Sunday, July 28, 2019 at 12:54:47 PM UTC-4, Dean Hoffman wrote:
On 7/28/19 11:44 AM, Dean Hoffman wrote:
On 7/28/19 11:09 AM, Dean Hoffman wrote:
On 7/27/19 10:31 AM, Arlen G. Holder wrote:
Â*From the US homeowner's perspective of working backward from a wall
outlet
o What is the difference between ground and neutral in the US?

A friend is debugging why the washing machine metal case is hot only
when
the water pipes are hooked up and water flowing through them when I
tried
to explain to that homeowner over the phone the difference between
ground
and neutral - where - I'm not sure I have it all figured out myself.

I'm going to point her to this answer on the net.

*Is this correct for ground?*
o It's the round hole in a 3-hole outlet
o It's usually a bare copper wire (or sometimes green).
o It's connected to the sub panel without any breaks whatsoever.
o From the sub panel it connects to the main panel sans any breaks.
o From the main panel it goes directly to the main inlet cold water
pipe.
o From that main cold water inlet pipe, it goes into a stake in the
ground.
o It should never carry current unless there is a problem somewhere.
o Therefore, the voltage from it to the ground should be zero.

*Is this correct for neutral?*
o It's the taller slot in the typical grounded US outlet box.
o It's the white insulated wire (when black or red is the hot wire).
o It's connected to the sub panel but it may have connections between..
o From the sub panel it connects to the main panel sans any breaks.
o From the main panel it goes directly to the power company input.
o Generally that power company input will be a power pole.
o Within a few power poles will be the step-down transformer.
o From that step-down transformer the neutral will go into the ground..
o Therefore, the voltage from the outlet neutral to ground should be
close to 0

In a way, they're similar in that both the ground and neutral
eventually go
directly into the ground - but they're different in that the neutral
carries current while the ground only carries current when something is
wrong.

Â*Â*Â*Â*Â*Â* This doesn't look quite right to me.Â* Electricity tries to
return to its source
through all available routes, not to ground.Â*Â*Â* You can have a lamp
and a tv running
on the same circuit, for example.Â* Two lamps with incandescent bulbs
of different wattage will work on the same circuit.
Â*Â*Â* Ground rods are for lightning protection.Â* They won't do any real
good
if there isÂ* a short to ground somewhere in the system.

Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* There's an illustration he
https://www.ecmweb.com/code-basics/nec-rules-electric-signs-and-outline-lighting

This one is a bit better:
https://www.bing.com/images/search?view=detailV2&ccid=dUIWgCvZ&id=4BC6F670DF37 A168AFF1C7C34BCCC4EE2FC41E8A&thid=OIP.dUIWgCvZFit3 kBa07xgd_AHaFj&mediaurl=http%3A%2F%2Fwww.mikeholt. com%2Fgraphics%2Ftouch.gif&exph=480&expw=640&q=Gro unding+Electrode+Requirements&simid=60800251866140 0842&selectedindex=55&ajaxhist=0&vt=0

Before I point the homeowner to this thread, can you clarify or fix
mistakes in my understanding of the difference between neutral & ground?




What they are showing there, the guy getting shocked, is similar to what
the washing machine lady has. It shows a guy touching the metal parts
of an outdoor sign that does not have it's metal connected to the
grounding conductor and a fault occurring, where the 120V hot touches
the metal. Instead of having the metal bonded and connected to the
grounding conductor, that sign instead used an illegal ground round and
a really bad one at that. Like the washing machine, if the eqpt was
properly connected to the required grounding conductor, the fault would
have tripped the breaker if it was a direct short. And if it was a
smaller short that did not trip the breaker, the case
would still not be at a significant difference in potential from the
metal appliance case next to it, a water pipe, etc. If that
washing machine circuit was GFCI, it would have tripped on even a 5 ma
current. This example shows why having them is a good idea.