The online UPS, sometimes called a true UPS, is the best type you can buy. Paradoxically, it is both very similar to, and totally opposite to, the least-expensive type, the standby UPS. It is very similar to it in that it has the same two power sources, and a transfer switch that selects between them. It is the exact opposite from the standby UPS because it has reversed its sources: in the online UPS the primary power source is the UPS's battery, and utility power is the secondary power source!

Block schematic of an online ("true") UPS. You will notice if you look at the schematic for the standby UPS that it is identical, except that the primary and secondary power paths have been exchanged, and here the battery is the primary power source.

Of course, while seeming small, this change is a very significant one. Under normal operation the online UPS is always running off the battery, using its inverter, while the line power runs the battery charger. For this reason, this type of UPS is sometimes also called a double-conversion or double-conversion online UPS. This design means that there is no transfer time in the event of a power failure--if the power goes out, the inverter (and its load) keeps chugging along and only the battery charger fails. A computer powered by an online UPS responds to a power failure in the same way that a plugged-in laptop PC does: it keeps running without interruption, and all that happens is that the battery starts to run down because there is no line power to charge it.

Online UPSs provide the highest level of power protection and are the ideal choice for shielding your organization's most important computing installations. Online UPSs offer complete protection and isolation from all types of power problems - power surges, high-voltage spikes, switching transients, power sags, electrical line noise, frequency variation, brownouts and blackouts. In addition, they provide digital-quality power not possible with off-line systems. For these reasons, they typically are used for mission-critical applications that demand high productivity and systems availability.

This is a 100% Power Quality solution

This type of UPS is Generator compatible