Connecting a 750 W DC Power Supply to the Source Voltage

Two 750 W DC power supplies are available: model XN-DCPWR-750W-F (front-to-back airflow) and model XN-DCPWR-750W-R (back-to-front airflow). Both can connect to a –48 V power source.

The DC power connection at your facility must be made by a qualified electrician, following these instructions:



Always make sure that the DC circuit is de-energized before connecting or disconnecting the DC power cables on the DC power supply.


Provide proper connection and strain relief on the DC power cables in accordance with all local and national electrical codes.
  1. Verify that the DC circuit is de-energized.
  2. Attach an ESD-preventive wrist strap to your bare wrist and connect the metal end to an appropriate ground point on the rack.
  3. Plug the connector that contains the negative (V+DC) and positive (V-DC) wires to the power supply.
  4. Connect the cables to the DC source voltage, using hardware appropriate to the installation site and following local and national electrical codes.

Power up to the switch, following the steps in Powering up the Switch.

Leave the ESD strap permanently connected to the rack, so that the strap is always available when you need to handle ESD-sensitive components.