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RE: Another 220v question

To: shop-talk@autox.team.net
Subject: RE: Another 220v question
From: Randall Young <ryoung@NAVCOMTECH.COM>
Date: Thu, 22 Aug 2002 10:15:42 -0700
> So if you have a single outlet run from the box to the outlet, what's the
> difference between neutral and safety?  Seems like they're both tied to
> the same thing at the box...  I.e. why can't you run one wire from box to
> the outlet and make it both neutral & safety, with another wire the hot
> wire?

If the neutral side opens up for some reason (broken wire, plug falling out
of socket, etc.), the load side of the broken neutral will go to the same
voltage as the hot wire.  If the same wire is the safety ground, it will
also become 'hot'.

Also, since there is current flowing in the neutral and wire always has some
resistance, the neutral will actually be somewhat above ground at the
outlet.  Granted, it should be no more than a few volts, but it can be
enough to cause problems.

Then of course, there are the fairly common wiring faults that intermix
neutral and hot ... I've seen this even in professional installations that
passed inspection ...

Obviously it will 'work' without a separate safety wire, but it does add
some measure of safety.

Randall

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