Cisco Systems 9000 Manual De Usuario

A separate ground connection is not required for the version 2 or version 3 power systems. For more 
information see the 

The color coding of source DC power cable leads depends on the color coding of the site DC power 
source. Because there is no color code standard for source DC wiring, be sure that power source cables 
are connected to the power modules using the proper positive (+) and negative (–) polarity:

In some cases, the source DC cable leads might have a positive (+) or a negative (–) label. This is a 
relatively safe indication of the polarity, but you must verify the polarity by measuring the voltage 
between the DC cable leads. Be sure that the positive (+) and negative (–) cable leads match the 
positive (+) and negative (–) labels on the power module when making the measurement.

Green (or green and yellow) cable typically indicates that it is a ground cable.

DC power modules contain reverse voltage protection circuitry to prevent damage to the power module 
if it detects a reverse polarity condition. No damage should occur from reverse polarity, but you should 
correct a reverse polarity condition immediately.

For a list of the nominal and acceptable value ranges for source DC power, see “Appendix A.”

364234

PWR A–

–48/60V PWR RTN A+

–48/60V RTN

Feed A, Slot M3

PWR B–

–48/60V PWR RTN B+

–48/60V RTN

Feed B, Slot M3