Uninterruptible Power Supply · UPS
Power system that keeps IT load energized through grid sags and outages until backup generation starts.
Current numbers
secondsloss-of-cooling thermal-trip window for 1 kW+ GPUs — UPS-backed pumps + N+1/2N rejection mandatory
45%of impactful data-center outages root-caused to power (most often UPS); IT/networking ~23%
~99.999%Google fleet-wide CDU availability since 2020 (redundant pump+HX, UPS-backed)