[mythtv-users] Power outages and UPSs

[David Brodbeck]

On Jul 30, 2007, at 3:25 PM, f-myth-users at media.mit.edu wrote:
> If you want -maximal- isolation, you hook a motor to a generator
> and you can get better isolation than even an isolation transformer
> will give you... :)

And there are sites that do that.  But it has its own unique issues.   
Now instead of the massive impedance of the power grid to smooth out  
quirks in your loads, you have a relatively small generator.  You  
become vulnerable to spikes created on your OWN site by big loads  
turning on and off.  Small generators can also easily lose voltage  
regulation in the presence of highly capacitive loads, which happen  
to include many computer power supplies.  Third-order harmonics  
created by switching supplies can wreak their own unique kind of  
poorly-understood havoc, as well.