MicroVAX 3800 Power Cable - test-drb@ccmp.vtda.org

7 Feb 2003

On Feb 7, 23:21, Tony Duell wrote:
...
  > On Feb 6, 22:33, Tony Duell wrote:
 >
 > > I don't see how you can do a proper test without a visual inspection
...
  > of
 > > the connections... And I've yet to see a moulded connector that
 > provides
 > > a proper strain-relief for the cable.
 >
 > A good PAT tester will check at a sensible current (though admittedly a
...
  > lot only check earth continuity at a proper
current).  As for strain
...

 I've never met a PAT tester that tests the current-carrying conductors at
...
  a significant current, mainly because there's no
easy way to do this
 without dismantling the unit under test (if the cable is fixed) -- the
...
  maximum current you could pass would be the normal
operating current of
...
  the unit (by simply applying mains to it), which is
not enough. Even then
...
  you couldn't measure the voltage drop across one
of the conductors. 
A proper PAT tester to current standards has a socket for each end of
an IEC cable, and each cable is supposed to be individually tested with
both ends plugged in to the tester.

...
  > releif, well you're not supposed to swing the
equipment by the power
...
   cable, Tony!

 True, but equally I don't expect the outer covering of the cable to pull
...
  out of the moulded connector in normal use exposing
the single-insulated
...
  wires inside. Which has happened to many moulded
cables round here. 
I've only seen one do that -- and it was an instant candidate for the
wirecutters at both ends.  A proper visual inspection is supposed to be
the first part of the PAT.

...
  I assume you'd fail a rewirable plug with the cord
grip missing/not used
...
  on an electrical safety test. I certainly would.

Yes.  The first thing I do with any multiblock is take it apart to see
how the ends are wired -- the cheap ones are usually in a condition
where I feel compelled to re-do the job.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York