HP SAS DL360 - Manual (Page 52)

52 HP ProLiant DL360 Generation 4p Server (SAS Model) User Guide
WARNING: To reduce the risk of electric shock or damage
to the equipment, do not connect the power cord to the power
supply until the power supply is installed.
4. Install the redundant power supply into the bay until it clicks.
5. Connect the power cord to the power supply.