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Old August 14th 03, 11:32 AM
Malcolm Reeves
 
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On Wed, 13 Aug 2003 12:59:45 -0700, Sparks
wrote:

UK's System is NOT a system that has a "Ground" Over Out Sparks W4EAS


Eh? Is this humour? UK household mains is 240V ac (235V ac now but
the tolerance band includes 240V so it many places is stayed the same
AFAIK). The lines are E (Earth, Green/yellow), Neutral (blue), Live
(brown, fused). E and N are at same potential, as is metalwork in the
house. L is 235V ac. So if you are holding L and it is on your house
is wired wrong, or you are Mr Rubber man.

FYI (non UK'ers) the common arrangement is called PME, Protective
Multiple Earth. The N line is bonded to earth (via the underground
cabling AFAIR). N is thus at low potential near earth. At the
company incoming fuse box the N line is split to E and N. The
customer gets E, N, and L wires. The E terminal is bonded to all
metal work, baths, plumbing etc. Hence you cannot get a shock from N
to E. Switches tend to be single pole in the L as switching L and N
would be dangerous if just N failed. You do get double pole so they
must have a fail safe scheme for those. Fusing is only in the L for
the same reason.


--

....malcolm

Malcolm Reeves BSc CEng MIEE MIRSE, Full Circuit Ltd, Chippenham, UK
, or ).
Design Service for Analogue/Digital H/W & S/W Railway Signalling and Power
electronics. More details plus freeware, Win95/98 DUN and Pspice tips, see:

http://www.fullcircuit.com or http://www.fullcircuit.co.uk

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