The switches have two bays for hot-swappable power supplies. In a switch with a redundant
power configuration, you can replace one power supply without powering down the switch.
Note
All installed power supplies must blow air in the same direction and must match the
airflow direction of the installed fan modules.
You need the following tools and materials to replace a 550 W AC or DC power supply:
#1 Phillips screwdriver
Torque screwdriver and wrench or
torque driver with attachments for tightening screws and nuts
Thermal protective gloves
(required for removal of a power supply)
Caution
Make sure that
the DC power supply circuit is not overloaded. Use proper overcurrent protection,
such as a circuit breaker, to prevent overcurrent conditions. You can use up to a
30-Amp breaker.
Replace a 550 W DC Power Supply
Warning
Be sure to disconnect all power cables before you disconnect the chassis ground
wire.
To replace a 550 W DC power supply, follow these steps:
Attach an ESD-preventive wrist
strap to your bare wrist and connect the metal end to an appropriate ground
point on the rack.
Note the orientation of the
installed power supply, and the location of the latching tab at the right of the
unit.
Push the latching tab toward the
power supply handle and pull outward on the handle to disengage the power supply
internal connectors.
Carefully slide the power supply
the rest of the way out of the switch.
Caution
Power supplies can become
very hot during operation. Wear thermal protective gloves when you remove a
power supply from an operating switch.
Note
If you are not installing a
replacement power supply, install a cover over the unoccupied power supply
bay. Unoccupied bays must always be covered to maintain proper system
ventilation and EMI levels.
Verify that the replacement power
supply is oriented the same way as the unit you removed, and has the same
airflow direction.
Carefully slide the power supply
all the way into the power supply bay until the latch snaps into place, as shown
in Installing A 550 W DC
Power Supply.
Caution
Do not slam the power supply into the switch.
Installing A 550 W DC
Power Supply
To install a second power supply,
repeat the procedure.
When you are finished, use the DC power input cable for the DC power supply to ground
the power supply and connect the power supply to the power source.
Warning
Connect the chassis
ground wire before you connect any power cables.
Connect a DC Power Supply to the
Source Voltage
The DC power connection at your facility must be made by a qualified electrician,
following these instructions.
Warning
Always make sure that the DC circuit is de-energized before connecting or disconnecting
the DC power cables on the DC power supply.
Caution
Provide proper
connection and strain relief on the DC power cables in accordance with all local and
national electrical codes.
Verify that the DC circuit is
de-energized.
Attach an ESD-preventive wrist
strap to your bare wrist and connect the metal end to an appropriate ground
point on the rack.
Position the DC power cable
connector so that the wide, flat side is closest to the fan, as shown in Connecting the DC
Power Cord. The DC power cable connector can only connect to the power
supply one way.
Connecting the DC
Power Cord
Tighten the two thumb screws to
secure the DC power connector in place.
The installation electrician connects the other end of the power cord to the
building power system.
Warning
Before installing, be sure to connect the chassis ground wire
before you connect any power cables.
Warning
Before
removing, be sure to disconnect the ground wire after you disconnect all
power cables.
Use the following for the building wire
harness:
Pin 1
Yellow/Green
GRD
Pin 2
Black
-48V
Pin 3
Red
RTN
Connect the ring terminal
of the yellow and green ground wire to a known reliable earth ground
point at your site.
DC Power
Cable
Connect the ring terminal of the red RTN power cable to the positive
terminal of the DC power source, and connect the ring terminal of the
black -48V power cable to the negative terminal of the DC power
source.
Repeat these steps for each power supply.
Leave the ESD strap permanently connected to the rack, so that the strap is always
available when you need to handle ESD-sensitive components.
