Dell POWEREDGE M915 - Manual (Page 7)

Getting Started With Your System
5
Connecting the System to Power
Connect the system’s power cables to the system power supplies.
CAUTION:
To prevent the power cables from being disconnected accidentally,
use the plastic clip on each power supply to secure the power cable to the
power supply, and use the Velcro strap to secure the cable to the strain-relief bar.
Plug the other end of the power cables into a power distribution unit (PDU).
CAUTION:
Do not plug the power cables directly into a power outlet; you must
use a PDU. For optimal system functionality, a minimum of three power supplies
are required.