02-10-2012, 01:23 PM
Online UPS
[attachment=35016]
Under normal operation, the online UPS is always running off the battery using its inverter while the line power runs battery charger. Thus, it is also called a double conversion online UPS. If the power goes out, the load continues to get power through the inverter and only the battery charging fails. Thus, there is no transfer time in the event of power failure, only the battery starts to rundown. If the primary equipment fails, then the transfer switch is used to switch to the utility power source. Here transfer time comes into play. Another key advantage to having the equipment running off the battery most of the time is that the double conversion process completely isolates the load from the line power.
[attachment=35016]
Under normal operation, the online UPS is always running off the battery using its inverter while the line power runs battery charger. Thus, it is also called a double conversion online UPS. If the power goes out, the load continues to get power through the inverter and only the battery charging fails. Thus, there is no transfer time in the event of power failure, only the battery starts to rundown. If the primary equipment fails, then the transfer switch is used to switch to the utility power source. Here transfer time comes into play. Another key advantage to having the equipment running off the battery most of the time is that the double conversion process completely isolates the load from the line power.