Lenovo 5594-8KX User, Installation And Maintenance Manual page 208

Chapter 11 Troubleshooting
Clearing the Error Message "Para. cable lost 0xC16"
Information
It may be that that the affected UPS unit has been incorrectly configured to "hot standby" a
feature that currently can not be ordered from Lenovo. As a result of this configuration change
the UPS will display the following in the LCD panel:
This message indicates that the required parallel cable has not been installed and the UPS
was not connected to its partner UPS.
Solution
This issue can be resolved by either reconfiguring the UPS unit as single or unitary UPS unit or
by resetting it to factory defaults in case changing it to unitary UPS unit does not work.
180 6U Rack or Tower UPS RT8kVA and RT11kVA IUOMG