Emerson Network Power recently released a white paper titled “Protecting Critical Systems During Outages: The Role of UPS Topology.” The paper features an analysis of the three UPS topologies in use today as defined by the International Electrotechnical Commission. The topology of a UPS system defines the relationship between the UPS and the incoming power source and determines the degree of power conditioning the system can deliver. Emerson Network Power manufactures all three types of UPS under its Liebert Corp. brand.
The paper then presents real-world examples of how each topology performed for different organizations during the August 2003 blackout. Two of the organizations reviewed employed two different UPS topologies in their facilities, allowing the performance of different topologies to be evaluated under identical conditions. The paper also outlines a 4-step process for auditing critical systems to ensure power protection systems are deployed in a way that reduces the financial impact of power outages.
Extended outages provide an extreme test of UPS performance. They are often preceded by huge fluctuations in power quality that can damage critical systems if the UPS does not effectively isolate protected equipment from the power source. During the outage, the UPS must provide sufficient uninterruptible power to ensure a safe shutdown or the successful transition to a backup power source, if one is available. The UPS is tested again after utility power is restored, a period in which extreme power anomalies may occur and UPS battery capacity may be depleted. The selection of an appropriate UPS topology can mean the difference between safely maintaining computer systems through a blackout and sustaining serious equipment damage and compromising data integrity.