Re: Potentially stupid question about AC

[CUTblakeney@home.com (Jeff Blakeney)]

On 21 Aug 1999 07:36:00 GMT, 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. :)

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