RE: Origins of UK standard 13Amp plug

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Colin Dancer by way of Terry Fritz <twftesla-at-qwest-dot-net>" <CMD-at-dataconnection-dot-com>

I'm sure I read in a book that it was the result of a BSI (British Standards
Institute) effort to come up with a replacement for the old 5A & 15A round
pin plugs (which you can still find in some older houses).  

The socket / plug combination includes a number of significant advances over
the previous designs:

*  a mandatory earth pin which is longer than the other two pins and
connects first / disconnects last
*  an integrated shield over the live / neutral pins which only opens when
the earth pin is engaged (stops little Johnny having fun with knitting
needles)
*  rectangular cross-section pins giving large flat contact areas which are
easily and efficiently mated by a flat contact strip
*  an overall design which means it is hard to accidentally pull a plug out
of a socket just by pulling the cable (not that this stops me occasionally
trying :-)
*  an integrated fuse which not only ensures all equipment is fused but also
eliminates the previous danger of equipment fuses ending up in the neutral
rather than live circuit when the plug wires were accidentally crossed over.

I'll see if I can find the original reference.

Colin.
-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: 26 April 2002 14:23
To: tesla-at-pupman-dot-com
Subject: Origins of UK standard 13Amp plug


Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<jimlux-at-earthlink-dot-net>

I have been asked if I know anything about the origins of the standard 13Amp
plug used in the UK.  Surely one of you UK coilers knows this (or where to
find out)?  (Although, I have to confess, I have no idea about the origins
of the standard 15Amp plug used in the US... but, at least I know where to
start tracking it down...)

Thanks in advance...
Jim