Installing Ac Or Dc Power Supplies - Dell S4820T Installation Manual

DC PSU and an AC-R PSU with a DC-R PSU. The fan airflow direction for both the PSUs must be the
same.
• To view the log messages, use the show logging command. For more information, refer to the
System Logs chapters of the FTOS Command Line Reference Guide for the S4820T System and FTOS
Configuration Guide for the S4820T System.
WARNING: Although the switch can run on one PSU, Dell Networking highly recommends using
two PSUs for full redundancy and proper cooling. To avoid overheating, if the switch needs to run
with only one PSU for a time, Dell Networking recommends using PSU0 (on the left) and covering
the second PSU slot opening with a blank plate.
WARNING: ESD damage can occur if components are mishandled. Always wear an ESD-
preventive wrist or heel ground strap when handling the S4820T and its components.
WARNING: DO NOT mix airflow directions. Both power supplies must use the same airflow
direction (I/O to Utility or Utility to I/O). If you mismatch the airflows, the system shuts down
within one minute.
WARNING: To prevent electrical shock, ensure the S4820T is grounded properly. If you do not
ground your equipment correctly, excessive emissions may result. To ensure the power cables
meet your local electrical requirements, use a qualified electrician.
WARNING: Prevent exposure and contact with hazardous voltages. Do not attempt to operate
this system with the safety cover removed.
CAUTION: Remove the power cable from the PSU prior to removing the PSU. Also, do not
connect the power cable before you insert the PSU in the chassis.
CAUTION: The DC PSU comes with a 6-8 inch power cord with a snap-in plug that attaches to the
DC power supply and screw terminals that attach to the main power. To ensure sufficient room,
Dell Networking recommends using a longer cable.
CAUTION: The power supply is marked + 48V - . Connect the + (plus sign) to the red cable on the
6-8 inch cord; connect the - (minus sign) to the black cable on the 6-8 inch cord. BE SURE TO
connect the RED cable to RETURN and the BLACK cable to -48V.
NOTE: To comply with the GR-1089 Lightning Criteria for Equipment Interfacing with AC Power
Ports, use an external SPD at the AC input of the router.

Installing AC or DC Power Supplies

1. Remove the PSU slot cover from the S4820T (PSU side of switch).
2. Remove the PSU from the electro-static bag.
3. Use the grab handle to slide the PSU into the switch PSU slot.
The PSU slot is keyed such that the PSU can only be fully inserted in one orientation.
When you install the PSU correctly, it snaps into place and is flush with the back of the switch.
4. Plug in the appropriate cord (AC 3 prong or DC wiring) from the switch PSU to the external power
source (either AC wall outlet or DC rack bus bar).
5. Repeat steps 1 through 4 for the second PSU.
NOTE: Ensure that you install the PSU correctly. When installed correctly, the power connector is
on the left side of the PSU and the status LED is at the top of the PSU.
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Power Supplies