Liebert Case Study - Time Warner


Time Warner

The major electrical outage that occurred in the United States in August 2003 represented a major test of business continuity plans and uninterruptible power performance. The combination of huge fluctuations in data center power quality that preceded the blackout, along with the outage itself, represented some of the most extreme conditions many data centers had ever experienced.

Case Summary
Location: United States


  • Liebert UPStation GXT UPS systems

Critical Needs
Protect revenue-generating data center equipment during the extended blackout that affected the United States in August 2003.


While the Liebert GXTs performed flawlessly throughout the blackout, the line interactive systems experienced a number of problems, including:

  • Batteries in the line interactive UPSs did not have the capacity to support the connected load while the back-up generators were started and stabilized; many shut down well before their rated back-up time and dropped critical loads unexpectedly.
  • The line interactive UPS units were unable to support start-up on exhausted batteries. When the utility restarted with “dirty” power, the line interactive UPSs attempted to go to their already-spent batteries, causing the units to shut down unexpectedly and drop the load.
  • After the blackout, the incoming power lost its neutral, and voltage jumped to 150 on one pole and dropped to 90 on the other. The line interactive UPS let this power anomaly through, destroying the power supplies on seven servers. Not even the loss of neutral affected the output power from the Liebert systems.

“Battery maintenance has been an ongoing problem with the line interactive systems because of the frequency that these systems have to go to battery,” said Scott Widney, IT manager at Time Warner. “It is a problem we have lived with until now by stockpiling extra batteries on site. But seeing the performance of the Liebert systems has convinced me that all of our critical systems need to be protected by double conversion UPS systems.”

 To read more, download the Time Warner case study.