HP UPS Extended Runtime Module - Manual (Page 22)

Installation 22
Connecting the ground bonding cable
NOTE: UPS appearance might vary depending on the specific unit installed.
The ground bonding screw is provided as an attachment point for conductors. Use a ground bonding
cable if the rack contains any conductors for the purpose of functional grounding or bonding of
ungrounded metal parts.
The ground bonding cable is not included.
Connecting the UPS to utility power