[Shop-talk] Electrical Outlet wiring question

[Steven Trovato]

Peter,
I don't think that is correct.  My house has two outlet circuits 
wired with a single run of 14-3 Romex and a 220 breaker.  Some 
outlets use one side of the 220, some use the other.  But they all 
use the common neutral.  This was reasonably common practice to save 
wire, and met the code, at least 25 years ago when my house was 
built.    Besides,  I don't think the loads add the way you say.  In 
fact, because they are out of phase, they cancel out.  This is why 
you try to balance the load between the two sides of the 220 at the 
panel.  DISCLAIMER:  I am not an electrician.  I can speak with 
authority on how my house was wired, but I'm not an authority on the 
National Electric Code, or whatever codes apply to where you live.

-Steve Trovato
strovato at optonline.net

At 05:16 PM 3/12/2010, Peter J. Thomas wrote:
>Do not use a common neutral.  Each outlet needs is own common return.
>If you use a 20A duplex break and 12 gauge 3 wire (4th wire bare 
>ground) romex (rated 20A IIRC) and install 20A outlets, the two hot 
>leads will be protected to 20A but a common return could be carrying 
>40A if you plug in 2 20A loads, twice the rating for 12 gauge.
>
>Peter Thomas