Power supplies
The S4048–ON ships with one AC power supply. Dell Technologies recommends purchasing a second power supply.
The S4048–ON supports AC power supplies with two air-flow directions, normal and reverse. Normal is from the I/O-side to the
PSU-side. Reverse is from the PSU-side to the I/O-side. Two PSUs are required for full redundancy, but the switch can operate
with a single PSU.
The PSUs are field replaceable. When running with full redundancy—two power supplies installed and running, you can remove
and replace one PSU without disrupting traffic.
NOTE: If you use a single PSU, install a blank plate in the other PSU slot. Dell Technologies recommends using power
supply 2 (PSU2) as the blank plate slot.
NOTE: ESD damage can occur if components are mishandled. Always wear an ESD-preventive wrist or heel ground strap
when handling the S4048–ON and its components.
CAUTION: To prevent electrical shock, ensure that the S4048-ON is grounded properly. If you do not ground
your equipment correctly, excessive emissions may result. Use a qualified electrician to ensure that the power
cables meet your local electrical requirements.
Topics:
• Components
• AC power supply installation
• DC power supply installation
Components
The following power supply options are available for the S4048–ON.
● AC power supply with integrated fan
● AC power supply with integrated reverse flow fan
Power supply 1 (PSU1) is on the left side of the chassis; power supply 2 (PSU2) is on the right side of the chassis.
Figure 12. S4048–ON power supply units (PSUs)
1. PSU 1
2. PSU 2
The PSUs have an integrated fan, which you cannot replace individually; if the fans integrated in a PSU fail, you must replace
the entire PSU. You can replace the fan trays individually. For fan tray replacement procedures, see Fans.
WARNING:
Prevent exposure and contact with hazardous voltages. Do not attempt to operate this switch with
the safety cover removed.
6
24 Power supplies