"N Cook" wrote in
:

Could someone direct me to pics of the 2 different types of
plug/socket system used in the USA to differentiate for medium and
high power use, I didn't even realise 220 or 240V was used
residentially anywhere in the USA.



http://nooutage.com/nema_configurations.htm

Some are used only in industrial and commercial situations though.

Not shown is the NEMA 10-xx configuration, which is used for the
aformentioned 120/240V appliances that use a neutral for chassis grounding
and as a return for internal 120V loads. They basically have angled hot
prongs with a straight or L shaped neutral prong (appropriately sized for
the load). FWIW, the NEMA 10-15 plug is exactly the same as a typical
Australian plug, less safety features.