Often caused by an overload, over-temperature, or rectifier failure.
A standout feature mentioned in technical documentation for this series is the use of patented digital Vector Control technology liebert hipulse d ups manual
Here are some common messages from the manual: Often caused by an overload, over-temperature, or rectifier
Visually inspect air filters and clean or replace them if necessary. Verify history logs for any unaddressed alarms. Often caused by an overload