Juniper T640 Hardware Manual page 359

Copyright © 2013, Juniper Networks, Inc.
Using both hands, slide the power supply into the chassis until you feel resistance
4.
(see Figure 192 on page
Twist the ejector handles at the upper corners of the power supply faceplate clockwise
5.
until they stop.
Tighten the captive screws at the lower corners of the power supply faceplate to
6.
secure the power supply in the chassis.
Verify that a licensed electrician has attached cable lugs to the power cables that you
7.
supply.
Remove the clear plastic cover protecting the terminal studs on the faceplate.
8.
Remove the nut and washer from each power terminal stud.
9.
CAUTION: You must ensure that power connections maintain the proper
polarity. The power source cables might be labeled
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.
Attach the lugs on the DC source power cables to the terminal studs.
10.
Attach the positive (+) DC source power cable lugs to the
a.
terminals.
Attach the negative (–) DC source power cable lugs to the
b.
Secure the cable lugs to the terminal studs, first with a washer, then with a nut (see
Figure 191 on page 328). Use a 7/16-in. (11 mm) nut driver to tighten the nut. Apply
between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut.
CAUTION: You must use an appropriate torque-controlled tool to tighten
the nuts. Applying excessive torque damages the terminal studs and the
power supply. The absolute maximum torque that may be applied to this
nut is 45 lb-in. (5.0 Nm).
Chapter 17: Replacing T640 Router Hardware Components
329).
and to indicate
(+) (–)
(return)
RETURN
(input) terminals.
–48V
327