Chapter 5 Maintaining the Cisco 12404 Internet Router
Removing and Replacing a DC PDU
5-20
Cisco 12404 Internet Router Installation and Configuration Guide
OL-11636-01
Step 1
Power off
both
PEMs.
Step 2
Power off the circuit breakers assigned to the DC power source.
Verify that all status LEDs on both PEMs are off.
Step 3
Loosen the terminal block screws to disconnect the positive, negative, and ground
wires from the DC PDU terminal block of the faulty PEM.
Caution
Before removing wires, be sure to note the color for each type of wire (positive,
negative, and ground). Because there is no color code standard for source DC
wiring, you must be sure which power wires are connected to the proper positive
(+) and negative (–) terminal ports. Typically, green (or green and yellow) indicate
a ground wire, while power wire leads may be labeled positive (+) or negative (–).
Because this is not always the case, the safest way to indicate the polarity of a wire
is to note its color and identify it as described in this procedure.
Warning
When disconnecting source DC power wires, always disconnect the ground
wire last.
Step 4
Loosen the captive screws securing the PDU and the PEM to the chassis.
Step 5
Remove the PDU/PEM from the chassis using the finger grips to pull it out.
Warning
A DC PEM and PDU weigh more than 11.0 lbs. (4.98 kg.). Use both hands to
remove it from the chassis.
Place the PDU/PEM on a table or other flat surface.
Step 6
Disconnect the PDU from the PEM.
Step 7
Connect the new PDU to the PEM (
todd.book Page 20 Tuesday, November 27, 2007 6:02 PM
