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

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

Warning To be completely sure that power has been removed from the source DC circuit presently servicing the power supply that you intend to remove, use a voltmeter to measure the voltage across the negative (–) and positive (+) source DC leads. 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 observing the following order of removal:

(a)– (negative)

(b)+ (positive)

(c)Ground

Step 8 Using a 10 mm nutdriver (or a 1/4-inch socket wrench with a 10 mm deep-well socket), loosen the nuts securing the negative (–) power cable to the bottom terminals on the power supply faceplate; remove the nuts and locking washers from the terminals; set this hardware aside temporarily and remove the power cable from the negative terminals.

Step 9 Proceed in like manner to remove the positive (+) and grounding cables from the power supply terminals, making sure that you remove the ground cable last.

Step 10 For added safety, place tape over the exposed lugs of the power cables to prevent contact between the leads.

Maintaining the Cisco 12008 7-33