Cisco ASR 9000 Series Manual page 53

Preparing for Installation
A separate ground connection is not required for the version 2 or version 3 power systems. For more
Note
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
Caution
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 Technical Specifications
chapter from Cisco ASR 9000 Series Aggregation Services Router Overview and Reference Guide
NEBS Supplemental Unit Bonding and Grounding Guidelines, on page
Cisco ASR 9000 Series Aggregation Services Router Hardware Installation Guide
Site Requirement Guidelines
54.
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