[Elecraft] Antistatic mat without electrical ground

[David Ferrington, M0XDF]

good article at
http://www.rsgb.org/emc/pdfs/leaflets/emc7protectivemultipleearthingmembers.pdf
on PME
-- The trees that are slow to grow bear the best fruit.
-Moliere, actor and playwright (1622-1673)

On 13 May 2008, at 18:29, Stephen Prior wrote:

> Don, and others
>
> In older houses in the UK the neutral is bonded to a real ground at  
> the fuse
> box, where the ground is usually a long copper rod just a few feet  
> away.
> There is rarely in my experience more than a volt or two on the  
> neutral.
>
> More modern houses use PME (protective multiple earthing) where the  
> neutral
> is bonded not at the house but locally at the final step-down  
> transformer-
> the argument being that this forms a higher quality ground I  
> believe.  The
> real danger with PME is that the neutral may well then rise above 0  
> volts,
> but in normal circumstances, because plumbing inside the house is  
> bonded to
> 'ground', no potential (!) exists for electrocution.  Until, that  
> is, a ham
> decides to ground his equipment 'properly' outside.  Then large  
> amounts of
> current can potentially flow!
>
> There was an excellent piece on this in Radcom many years ago by Peter
> Chadwick G3RZP I think.  Ian, GM3SEK will no doubt remember and also  
> know
> far more than me about the issue!