Cisco Systems Cisco 12008 manual Adding, Removing, or Replacing a DC-Input Power Supply

Adding, Removing, or Replacing a DC-Input Power Supply

To remove the plastic safety shield (see Figure 7-7), take the following actions:

(a)Loosen the knurled thumb wheel on the bottom left standoff that secures the safety shield to the power supply faceplate.

(b)Grasp the safety shield and move it to the right and obliquely upward, positioning the shield so that it can be freed from the three standoffs on the power supply faceplate.

(c)Remove the shield from the standoffs and set it aside temporarily.

Warning To be completely sure that power has been removed from the source DC circuit that is presently servicing the power supply, use a voltmeter to measure the voltage across the negative (–) and positive (+) source DC leads on the power supply. Set the voltmeter to a range that makes it capable of measuring up to 75 VDC. The measurement across the positive and negative leads should be zero (0) volts.

Step 5 Before removing the power cables, write the name of each cable on a piece of tape, as follows:

•

•

•

Ground

+(positive)

–(negative)

Step 6 Attach each piece of tape to the appropriate cable to identify it for later reconnection.

Step 7 Remove the power cables from the power supply terminals; strictly observe the following order in removing the cables:

(a)– (negative)

(b)+ positive)

(c)Ground

7-30Cisco 12008 Gigabit Switch Router Installation and Configuration Guide