N Cook wrote:
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.

There are several kinds depending upon the current rating and if 120
volts is used too. Before 1996, the ground pin was also used for neutral
for things like clothes dryers that had a 120 volt motors and timers and
240 volt heaters. I think that practice was stopped in the late 1970's.

In 1996, it became illegal. If your device has a mixture of 120 and 240
volt components, you need to have a four wire plug. I left the U.S. in
1996, so I've never seen them.

The simplest kind is used for air conditioners and is similar to a 120
volt grounded plug, with two flat blades and a rounded ground pin below
them in the middle. The difference is that the flat blades are the same
size and are horizontal instead of vertical.

I remember walking into an electronics store in SoHo (in Lyle Street?)
around 1983 and talking to the owner for a while. We got on to discussing
the differences in power cords and he showed me the 240 volt cords
they sent to the U.S. He was surprised that I was familar with them.

He also showed me a catalog from a U.S. company called Herbach and Rademan
that sold surplus electronics. He imported items from them. It was
my turn to be surprised, I lived less than 2 miles from them and was
a frequent customer. :-)

By 1989, the store was gone, it had become a Chinese grocery. In 2001 I
was given a stack of U.K. radio magazines and an article about the
store was in one of them. It was written by the nephew of the man
I spoke to. Unfortunatley he had no pictures of the store near the
end, and although I took many photographs of London that trip, I
never thought to take one of the store or his uncle. :-(


Geoff.
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Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
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