🚀 go-pugleaf

>This is a well known, SERIOUS and DANGEROUS problem.  It is NOT good
>for the power supply and will eventually lead to premature and
>catastrophic failure.  To say nothing of what the line surges will do
>to your data!!
  
>It is caused by an ungrounded neutral - a code violation as well as a
>safety hazard.
 

While this is a very likely cause, it is not necessarily the only one.  
Problems "upstream" from your service entrance can also cause voltage
fluctuations.  SO - if you check your neutral and safety ground connections
and find everything both hunky and dory, DON'T just resign yourself to
the problem.  Call the utility company, and demand that they get their
act together.  (It may take some convincing - I had an experience with a
P.S. co. in Indiana which flatly denied the problem until shown the charts
from a recording voltmeter (chart recorder) - but you do have a right to 
decent electrical service!)

 
Bob Myers  KC0EW   HP Graphics Tech. Div.|  Opinions expressed here are not
                   Ft. Collins, Colorado |  those of my employer or any other
myers%hpfcla@hplabs.hp.com               |  sentient life-form on this planet.