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Ralph Mowery typed:
wrote in message
...
We recently had one burnt electrical outlet at our office.
The appliance plug is also burnt as well. All the outlets
at our office is rated at 20Amps and have fuse protection.
The fuse did not trip. Anyone has a clue why the outlet
and the plug are burnt? I am planning to just replace the
burnt outlets and the appliance plug, but I really prefer
to know what caused the burning in the first place. Here are 2 photos
showing the plug and the outlet:

http://www.flickr.com/photos/54230006@N07/5341105173/
http://www.flickr.com/photos/54230006@N07/5341718398/

Thanks

Without having a beter look , I would say that in the plug
where the wire is connected to the prong, there is a loose
or high resistance connection.
You usually get heat build up at the bad connections. If
the plug can be taken apart, see if the connection is
loose. Unless there is some reason the whole prong is not
making connection all over the plug and socket, there
probably was nothing wrong with the socket except the plug
overheated and caused the burnt spots on the socket.

Since non-residential wiring is often stranded wire, that's a very good
possibility.