Issue:
Some customers may experience hearing a frequent clicking sound while their UPS is compensating for high input voltage.  

Product Line:
Smart-UPS

Environment:
This issue can affect SMX series Smart-UPS 1500va or less. UPS Firmware rev 3.7 or lower.
SMX750, SMX750-NMC, SMX1000, SMX1500RM2U, SMX1500RM2UNC
Cause:
UPS firmware must be upgraded to 3.8 or higher

Resolution:
Refer to KBASE document #FA164737 to upgrade the firmware.