This paper provides guidance for deciding what to do with older three phase, uninterruptable power supplies (UPSs). The answer is not always self-evident and will depend on many factors. The primary factors are:

  • Present UPS conditions/capabilities
  • Future requirements/constraints

Once a UPS has been in service for 10 years or so, the following three options present themselves to the owner as potential options:

  1. Buy new – Should the UPS be replaced with a new one?
  2. Upgrade - Can it be revitalized in some way to extend the life and performance for several more years?
  3. Do nothing - Or is it better to do nothing beyond the most basic maintenance and just let it, in effect, “run-to-fail”?

Surprisingly, each of these options has a set of circumstances that would make it a rational choice. Each has their own set of advantages and disadvantages.

This paper will review these options in the context of the primary factors listed above. A simple step-by-step framework for making the decision is provided along with recommendations to help ensure data center managers make their decision based on a full accounting of their own requirements and constraints.