Setup Guide
b Slot
When you install the PSU correctly, it snaps into place and is ushed with the back of the switch.
4 Plug in the appropriate AC three prong power cord from the switch PSU to the external power source.
5 If you have a redundant PSU, a second PSU, repeat steps 1 through 4 above using the second PSU slot on the S4048-ON switch.
NOTE: The S4048-ON powers up when the cables are connected between the power supply and the power source.
AC power supply replacement
CAUTION: Disconnect the power cord before removing the power supplies. Also, disconnect all power cords before servicing.
NOTE: The PSU slides into the slot smoothly. Do not force a PSU into a slot as this action may damage the PSU or the S4048–
ON chassis.
NOTE: If a PSU fails, you must replace the entire unit. There are no eld serviceable components in the PSU. To request a
hardware replacement, refer to Technical Support.
NOTE: If you use a single PSU, install a blank plate in the other PSU slot. If you are only using one power supply, Dell EMC
recommends installing the power supply in the rst slot (PSU1) and installing a blank plate in the second slot (PSU2).
1 Disconnect the power cable from the PSU.
2 Use the grab handle to slide the PSU out of the power supply bay.
3 Use the grab handle on the replacement PSU to slide it into the power supply bay.
4 Attach the power cord to the replacement PSU.
NOTE
: The switch powers up when the cables are connected between the power supply and the power source.
DC power supply installation
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 qualied electrician to ensure that the power cables meet your local electrical
requirements.
WARNING: The switch must have either AC power supplies or DC power supplies. You cannot mix power supplies.
NOTE: The PSU slides into the slot smoothly. Do not force a PSU into a slot as this action may damage the PSU or the S4048-
ON chassis.
NOTE: If you use a single PSU, install a blank plate in the other PSU slot. If you are only using one power supply, Dell EMC
recommends installing the power supply in the rst slot (PSU1) and installing a blank plate in the second slot (PSU2).
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.
NOTE: If a PSU fails, you must replace the entire unit. There are no eld serviceable components in the PSU. To request a
hardware replacement, contact Technical Support at www.dell.com/support.
Power supplies 27