This is the best option for immediate power restoration as far as I can tell.  But a number of these have been recalled over the years.  They can suddently decide to heat up and burn!   While this is uncommon, it happened to me.  They will replace the unit without cost, and it doesn't even interrupt power when it start to burn!  I was just lucky I was there when it started and could unplug it.

So keep abreast of any problems with the brand you purchase and follow all the installation recommendations faithfully.  It's a great system.

Monona


In a message dated 7/12/2010 12:50:43 PM Eastern Daylight Time, erclark**At_Symbol_Here**PH..LACOUNTY.GOV writes:

Kathleen,
Most emergency power generators typically don't service the entire building, just the critical systems, and those are the ones with the red plugs or otherwise hard-wired into the building grid.  Even that might not suffice for your needs, a typical emergency power generator requires 6 or 7 seconds before it actually restores power.  But as we all know, that kind of power interruption can disrupt hundreds of sensitive automated laboratory analyses that took hours to set up.  As Arnold would say:  Beeeg Problem (especially if you have insufficient samples for re-runs!). 
That's where the Uninterrupted Power Supply (UPS) comes in.  It's basically a bank of several dozen continually-charging car batteries that will provide sufficient continuous AC power for 10 - 15 seconds to ultra-critical systems until the emergency power generator kicks in.  And there are no moving parts.  There are lots of different kinds out there.  We happen to use the Eaton Powerware 9390 - actually two of them, set up side by side. 
One more thing about the UPS.  Don't forget to report the lead and sulfuric acid on the annual Community Right To Know forms AND tell the local fire department about them and show them where they are! 
Eric

Eric Clark, MS, CCHO, CHMM
Safety &Compliance Officer
Los Angeles County Public Health Laboratory