Dell PowerEdge R210 - Manual (Page 7)

Getting Started With Your System
5
Securing the Power Cable
Bend the system power cable as shown in the illustration and secure the cable
in the retention clip.
Plug the other end of the power cable into a grounded electrical outlet or
a separate power source such as an uninterrupted power supply (UPS) or
a power distribution unit (PDU).
Turning On the System
Press the power button on the system and the monitor. The power indicators
should light.