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Cable with low resistance (indicating a closed circuit) to chassis ground is RTN.
CAUTION:
You must ensure that power connections maintain the proper polarity. The power
source cables might be labeled (+) and (–) to indicate their polarity. There is no standard color
coding for DC power cables. The color coding used by the external DC power source at your site
determines the color coding for the leads on the power cables that attach to the terminal studs on
each power supply.
6. Remove the clear plastic cover from the terminal studs on the faceplate,.and remove the nut and washer from each
of the terminal studs.
7. Secure each power cable lug to the terminal studs, first with the flat washer, then with the split washer, and then with
the nut. Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut. Do not overtighten the nut.
(Use a 7/16-in. [11-mm] torque-controlled driver or socket wrench.)
•
On INPUT 0, attach the positive (+) DC source power cable lug to the RTN (return) terminal. Repeat this step for
INPUT 1 if using two feeds.
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On INPUT 0 attach the negative (–) DC source power cable lug to the –48V (input) terminal. Repeat this step for
INPUT 1 if using two feeds.
CAUTION:
Ensure that each power cable lug seats flush against the surface of the terminal block
as you are tightening the nuts. Ensure that each nut is properly threaded onto the terminal stud.
The nut should be able to spin freely with your fingers when it is first placed onto the terminal
stud. Applying installation torque to the nut when improperly threaded may result in damage to
the terminal stud.
CAUTION:
The maximum torque rating of the terminal studs on the DC power supply is 36 in-lb.
(4.0 Nm). The terminal studs may be damaged if excessive torque is applied. Use only a
torque-controlled driver or socket wrench to tighten nuts on the DC power supply terminal studs.
8. Verify that the power cabling is correct. Ensure that cables do not touch or block access to switch components, and
do not drape where people could trip on them.
9. Replace the clear plastic cover over the terminal studs on the faceplate.
10. Secure the grounding cable lug to the grounding points, first with the washers, then with the ¼-20, ½-in. screws.
11. Switch on the dedicated customer site circuit breakers.
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