In ,
dpb typed:
On 4/1/2011 3:33 PM, dpb wrote:
...

AFAIK, 15 and 20A outlets are both UL tested for 20A;
the only difference is the prong arrangement to not
allow a 20A cordset to plug into a 15A outlet but the
15A plug is still ok w/ a 20A breaker. I know this is so for 120V and
while I didn't go look at
the current UL protocol I'm virtually positive the same
is true for 250V rated outlets. ...

UL 498 contains the following for overload testing--

"A flush or self-contained receptacle having a 5-15R,
5-20R, 6-15R or 6-20R configuration shall be subjected to
the overload test described in this Section."

So the section covers both 125V and 250V together w/ the
same test reqm'ts.

No , you don't read ANY UL (or any safety spec) and go to work based ONLY on
that spec. You have to also read any references it gives, and any specs on
how it's connected, to what, and so on. The fact that UL accepts any
component is ALWAYS dependent on how that component is used. UL DOES NOT
test for real-world applications; it specs what can be connected to it via
more specs, NOT components. It is far from putting a UL tag on a complete
system when it's only part of a complete system, other parts of which are
unknown, so those specs must be interpreted also.
Worked meeting UL specs in designs for ten years, compliance to specs for
another then.