Path: utzoo!attcan!uunet!pilchuck!ssc!mcgp1!jgo
From: jgo@mcgp1.UUCP (John Opalko, N7KBT)
Newsgroups: sci.electronics
Subject: Re: Polarized Plugs for 120 VAC
Keywords: house, wiring, safety, single phase, USA
Message-ID: <1669@mcgp1.UUCP>
Date: 16 Nov 88 22:40:00 GMT
References: <686@bnlux0.bnl.gov> <4759@bsu-cs.UUCP>
Organization: McCaw Cellular Communications, Inc., Seattle, WA
Lines: 21

In article <4759@bsu-cs.UUCP>, dhesi@bsu-cs.UUCP (Rahul Dhesi) writes:
> It seems to me that it would be far safer to have each of the two hot
> wires be at +/- 55 volts relative to ground.  A grounded center-tapped
> secondary would do it.

Your house feed is already on a grounded center-tapped secondary.  That's how
you get 120V for your lights, etc., and 240V for your water heater, etc.

The neutral (white) wire on your 120V outlets is connected to the
distribution transformer center tap.  The hot (black) wire is connected to
one or the other end of the secondary winding.

If you look at a 240V outlet, you will see two hot wires (typically one
black and one red, but they can be any color except white or green), a
ground wire (green or bare) that MUST NOT carry current, and maybe a white
neutral that can be a current carrier.  The ground is required for safety.
The neutral is needed only if you require dual voltages from the outlet.



					John Opalko