Procedure
Step 1
Set the power switch at the rear of the AC power tray to the OFF (0) position.
Step 2
Power off (0) the circuit breakers assigned to the AC power sources that you are disconnecting.
To ensure that power remains off while you are performing this procedure, lock-out/tag-out the
circuit breaker switch in the OFF (0) position until you are ready to turn it on.
Warning
Step 3
Loosen the retainer bracket that holds the AC power cords to the power tray receptacle.
Step 4
Unplug the AC power cords from the power tray receptacles.
Reconnecting AC Power
To reconnect an individual AC power cord to a power tray, see
Connecting Power to an AC-Powered Chassis,
on page 184
Disconnecting DC Power
It is not necessary to disconnect all power from the chassis to replace components, including power
modules. See
Removing and Replacing Chassis Components, on page 235
Caution
Follow these steps to disconnect an individual DC power source from a power tray:
Procedure
Step 1
Power off the circuit breaker assigned to the DC power source you are disconnecting.
To ensure that power remains off while you are performing this procedure, lock-out/tag-out the
circuit breaker switch in the OFF (0) position until you are ready to turn it on.
Warning
Step 2
Remove the clear plastic safety covers that fit over the DC power connection terminal studs.
To prevent injury and damage to the equipment, always remove the source DC power cables from
the power tray terminals
in the following order
: (1) negative (
–
), (2) positive (+).
Warning
Step 3
Disconnect the DC power cables from their terminals in the following order and note the color of each cable:
a) Negative (PWR) cables first.
b) Positive (RTN) cables last.
Step 4
Repeat Step 1 through Step 3 for the other power module distribution that needs to be removed.
What to Do Next
If it becomes necessary to disconnect all DC power from the chassis, follow these steps:
Hardware Installation Guide for Cisco NCS 4000 Series
190
Installing Power Components
Reconnecting AC Power
