Installing Power Supplies
Before you begin
If the PSU blank module is inserted, remove it as follows:
- Unscrew the locking screw.
- Gently pull the power supply blank module out of the bay.

- Power supply blank module
- HVAC/HVDC power supplies automatically use the same airflow direction as the installed fan modules.
- To implement n+n redundancy, there must be two external power sources and two PSUs attached to each power source. Otherwise, only one power source is required.
- There must be an earth ground connection to the chassis to which you are installing the replacement module. Typically, the chassis is grounded by its metal-to-metal connection with a grounded rack. If you need to ground the chassis, see Grounding the Switch.
About this task
You can replace one power supply while the other one provides power to the switch.