UPS electrical problem

[Benjamin Scott]

On Thu, Jul 1, 2010 at 6:22 PM, Steven W. Orr <steveo at syslang.net> wrote:
> Pull the plug and see how long it lasts

  It's best not to literally pull the plug out of the receptacle.
Doing so disconnects the earth ground.  That can cause problems.  Some
signal links can be perturbed by loss of ground, or change in
potential.  And if you've got a signal cable connecting you to
equipment still grounded, you can get current following *that* path to
ground and causing all manner of weird behavior, possibly even damage.

  Flipping a switch on a power strip, or a circuit breaker, will just
disconnect the "hot" wire, leaving neutral and ground connected.

-- Ben