Table of Contents
Advertisement
5. Remove the plastic cable cover from the DC power input terminals by using the Phillips (+) screwdriver, number 2, to
loosen the screws.
6. Remove the nuts from each DC power input terminal, using the 13/32 in. (10 mm) nut driver or socket wrench to
loosen the nuts.
7. Ensure that the power source circuit breaker is open so that the voltage across the DC power source cable leads is 0
(zero) V and that the cable leads do not become active while you are connecting DC power.
8. Verify that the DC power cables are correctly labeled before making connections to the power supply. In a typical
power distribution scheme where the return is connected to chassis ground at the battery plant, you can use a multimeter
to verify the resistance of the –48V and RTN DC cables to chassis ground:
The cable with very high resistance (indicating an open circuit) to chassis ground is negative (–) and will be installed
on the –48V (input) DC power input terminal.
The cable with very low resistance (indicating a closed circuit) to chassis ground is positive (+) and will be installed
on the RTN (return) DC power input terminal.
CAUTION:
cables might be labeled (+) and (–) to indicate their polarity. There is no standard color coding for DC
power cables.
9. Install each power cable lug on the DC power input terminal, securing it with the nut (see
24 in.-lb (2.7 Nm) and 25 in.-lb (2.8 Nm) of torque to each nut. (Use the 13/32 in. [10 mm] nut driver or socket wrench.)
a. Secure each positive (+) DC source power cable lug to the RTN (return) DC power input terminal.
b. Secure each negative (–) DC source power cable lug to the –48V (input) DC power input terminal.
Each power supply has two independent sets of DC power input terminals (INPUT 1: RTN –48V/–60V: and INPUT
2: : RTN –48V/–60V). For feed redundancy, each power supply must be powered by dedicated power feeds derived
from feed INPUT 1 and feed INPUT 2. This configuration provides the commonly deployed INPUT 1 / INPUT 2 feed
redundancy for the router.
You must ensure that power connections maintain the proper polarity. The power source
Figure
20). Apply between
24
Advertisement
Table of Contents
