Re: Potentially stupid question about AC

[supertimer@aol.com (Supertimer)]

CUTblakeney@home.com (Jeff Blakeney) wrote:

>supertimer@aol.com (Supertimer) wrote:
>
>>But isn't this AC?  Why would the electrons only travel back to
>>the power plant through the neutral line.  I thought the polarity
>>reverses itself 50 or 60 times a second.  Isn't it more like the
>>electrons being pushed back and forth through the wire(s)?  I
>>would imagine that only with DC do the electrons get pushed
>>through a one way loop around the circuit.
>
>What he's getting at is that the neutral wire is only a return path.
>The neutral wire doesn't have any power at the other end.  There is no
>difference in the electric potential (voltage) between the ground you
>are standing on and what the neutral wire is connected to so no
>circuit is completed, there is no flow of electrons and therefore no
>shock.
>
>The live wire on the other hand does have power at the other end.  In
>this case, there is a difference in electric potential (voltage)
>between the ground you are standing on and what the live wire is
>connected to so a circuit is completed, there is flow of electrons and
>therefore a shock.
>
>Here are some simplified diagrams to help illustrate:
>        ____________
>     + |      LIVE
>     POWER
>     PLANT
>     - |             O
>       |____________/|\
>       |   NEUTRAL  / \
>       |              |
>     GROUND         GROUND
>
>In this case you are completing a circuit between ground and ground.
>No voltage is involved so no shock.
>
>                     O
>        ____________/|\
>     + |      LIVE  / \
>     POWER            |
>     PLANT            |
>     - |              |
>       |____________  |
>       |   NEUTRAL    |
>       |              |
>     GROUND         GROUND
>
>In this case you are completing a circuit from some power source to
>ground so you will end up having electricity flow through your body to
>ground.  Shocking, isn't it?  (Sorry I couldn't resist.  Actually I
>could have but I didn't want to. :)

Wow!  Now it all makes sense.  So if I connect the live wire
to one terminal on a light bulb and a second terminal to a
wire that I connect to a stake I drive into the ground, the
bulb would light?  Amazing.

That's similar to how the electrical system in a car works,
except the negative terminal of the battery is connected to
the metal body of the car which is the ground.

I'd just like to ask one more thing, though.  I assume that
in the above diagrams, the live and the neutral wires
switch their "+" and "-" 50 or 60 times a second depending
on the country (50Hz or 60Hz).

SO, I guess the real difference between live and neutral
wires is that the neutral wire is grounded, right?