On Sat, 21 Apr 2001, Clint Wolff (VAX collector) wrote:

> 
> 
> On Sat, 21 Apr 2001 jkunz@unixag-kl.fh-kl.de wrote:
> 
> > Protective ground is identical to N. It is only an extra wire to the N
> > point. This is needed for protection only. (Therefore it is called 
> > protective ground. ;-)  )
> 
> Some clarification is in order...
> 
> Protective ground is NOT identical to N, even if they are wired together
> at the main breaker panel (as in USA). Neutral is a current carrying
> conductor, and because of the resistance in the wire, it may be at some
> voltage above ground potential. This is why you NEVER attach the
> neutral to the protective ground. 

What he said!

> 
> Remember: if there is any possibility of current flow, use the Neutral
> wire.

The only purpose of the green (ground) wire is to help the overcurrent
device operate-- it is there to make what might be a small leakage to an
electrically isolated chassis into a large fault to ground.  

> 
> Remember: Always connect the protective ground to the chassis of the
> machine.

Do this, and also connect the other end...  (Also, in the US, the old
three-prong dryer & range cords are illegal now.  Be sure and use a proper
cordset, that provides an equipment ground)

> 
> These voltage are high enough you can destroy valuable antique hardware,
> which would be bad. You might get shocked too...

in that order...

> 
> clint

Bob