Dell PowerVault NX300 Getting Started Manual page 6

Optional – Connecting the Keyboard, Mouse, and Monitor
Connect the keyboard, mouse, and monitor (optional).
The connectors on the back of your system have icons indicating which cable
to plug into each connector. Be sure to tighten the screws (if any) on the
monitor's cable connector.
Connecting the Power Cable(s)
Connect the system's power cable(s) to the system.
4
Getting Started With Your System