wrote:
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
My neighbour had a fire in an 4-outlet box(industry quality) 4 days
ago.
Turned out, one of the screws was not tightened enough,
the insulation had burned off 2 inches of wire, and a short
developed, where the wire touched the other feed wire, but current
was not enough to trip the fuse, because there was no actual metal
contact, just carbonized insulation(when hot, that conducts).
After checking out the whole box, 6 screws turned out to be tightened
rather sloppy.
So, it might be prudent to check out wiring and screws in your office.

In our case, the outlets were high quality, but assembly sucked.
The outlet in question fell apart when checked out.