5-15
Cisco MGX 8260 Hardware Installation Guide
78-10966-02
Chapter 5 Connecting the Cables
Applying DC Power
Step 5
Connect two return cables, one to each MGX 8260 RTN terminal for power circuit A. Connect the other
ends to the RTN terminals at power source A.
Step 6
Connect two supply cables, one to each –48V terminal for power circuit A. Connect the other ends
through –48V circuit breaker terminals for power circuit A.
Warning
All four power terminals must have cables. A single supply and return cable pair will not support
a fully loaded MGX 8260 chassis.
Step 7
Install the power circuit cover. Slide the tab at the top of the cover into the chassis, and then lower the
body over the terminals, making sure the power cables exit through separate slots in the bottom of the
cover. (See
Figure 5-12
.)
Caution
Make sure the power terminal cover is correctly seated and that the power cables pass freely through
the openings at the bottom. Exposed power terminals or damaged insulation pose a safety risk to
personnel.
Step 8
Secure the cover with the two captive screws.
Step 9
To install redundant power circuit protection, repeat
Step 3
through
Step 8
for power circuit B,
connecting the MGX 8260 power cables to power source B.
Step 10
A logical view of MGX 8260 power connections is shown in
Figure 5-10
. A rear view of the MGX 8260
with power connections installed is shown in
Figure 5-11
. Verify that your power connections have been
made as shown in these figures.
Caution
The MGX 8260 is not equipped with an internal disconnect device. To power down the node, you
must turn off the devices protecting the power feeds. If the MGX 8260 is powered from redundant
feeds, both devices must be turned off.
Step 11
Apply DC power by switching the circuit breaker on.
Figure 5-10 MGX 8260 Power Connections (Logical Diagram)
-48VDC
Source B
-48VDC B
RTN B
-48VDC A
RTN A
Disconnect
devices
Multiple 12 AWG
wires
-48VDC
Source A
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