Surge suppressors

Robert G. Brown rgb at
Sun Nov 3 09:02:52 PST 2002

On Sat, 2 Nov 2002, Bob Drzyzgula wrote:

> I find that hard to believe; I'd be interested in seeing
> that picture you speak of.

The URL to it was in my first reply in this thread.  It was a Los Alamos
problem report.  However, going back over it, it looks like the problem
was that the plug was improperly wired, not the receptacle, although the
report shows the charred receptacle and begins that the "plug and
receptacle" were destroyed.  It was a 20 Amp device wired and connected
with a plug rated for only 15 Amps.  Now that I understand that there
exists a "20 amp plug", it makes sense.

In summary, "15 amp" receptacles should always be able to carry 20 amps
safely enough, but plugs designed to fit into them are unlikely to be
able to carry 20 amps (unless one uses 12 gauge cord, and even so it
would probably be a code violation).  One can therefore use "15 amp"
receptacles safely on a 20 Amp breaker because even if one does overload
a cord or do something else dumb within the room, the wiring in the wall
including the receptacle itself should withstand 20 Amps safely.  The
plug, the appliance cord, etc of course may well melt and burn, but the
walls should be safe enough.

Good.  I learned quite a bit from this whole discussion.  Thanks to the
many who contributed.


Robert G. Brown	             
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at

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