I've got a question on how UPS backup works. I've got a APC UPS backup for my iMac at work. Recently we had a power outage at work, and even though the iMac was connected into the "battery backup", the machine was powered off when I got back to it. The sys-admin at work says that these UPS will briefly cut power to the computer to signal when power has been restored. This seems counter intuitive to me. Is that true? Since then, I've now connected the iMac to the UPS via a UBS connection, and configured the Mac OS-X settings found under "System Preference", "Energy Saver" on the "UPS" and "Options" tabs. Does anyone knowledge able in this area have advice for good settings. I've got the following Shutdown the computer when it has been on UPS for: 5 min. Shutdown the computer when the time left on UPS is: 2 min. Shutdown the computer when the UPS power level drops to: 25%. On the "Options" tab all te "Other Options are set including: Restart automatically after a power failure.