The device's filtering circuits feed computers, servers or related network equipment that could otherwise shut down or lose data during brief power interruptions. If you're working at your computer and electrical power to your office goes out, several bad things can happen. Boeing IT not all shook up by quake White Papers Uninterruptible Power Supplies For one thing, you could lose important data. And if the failure occurs while your system is writing data to disk, the disk's logical structure could suffer serious damage, and some files could be lost.
Longer interruptions mean more trouble.
If your servers are affected, you could lose both business from customers and productivity from employees. According to an IBM study, a workstation has more than 120 power problems per month. Each UPS you select should equal or exceed the total power requirements of the equipment connected to it. To determine an individual VA rating, multiply voltage times amperage, or, to convert from AC watts, multiply wattage by 1.35. After you calculate the VA rating for each device, add them all together to get a total for all your equipment.