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Cisco Network Convergence System 4000 Series Hardware Installation Guide
Chapter 4 Installing Power Components
Power Connection Guidelines
Figure 4-3
Typical DC Power Cable Lugs
Warning
To avoid shock hazard, be sure to apply shrink wrap tubing around the wire entry area of the lug.
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.
•
A green (or green and yellow) cable typically indicates that it is a ground cable.
Caution
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
364
88
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