Juniper MX2020 Hardware Manual page 159

Copyright © 2013, Juniper Networks, Inc.
Remove the nut and washers from each of the terminal studs. (Use a 7/16-in.
7.
[11 mm] nut driver or socket wrench.)
Secure each power cable lug to the terminal studs, first with the split washer, then
8.
with the nut (see Figure 79 on page
(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.)
a. Secure each positive (+) DC source power cable lug to the
b. Secure each negative (–) DC source power cable lug to the
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 the nut is improperly threaded
may result in damage to the terminal stud.
CAUTION: The maximum torque rating of the terminal studs on the DC
PDM is 25 lb-in. (33.89 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 PDM terminal studs.
NOTE: The DC PDMs in slots
by dedicated power feeds derived from feed
provides the commonly deployed
balance the power draw.
Close the plastic cable restraint cover over the terminal studs on the faceplate.
9.
Route the positive and negative DC power cables through the left and right sides of
10.
the cable restraint.
Tighten the cable restraint captive screw to hold the power cables in place.
11.
CAUTION: The maximum torque rating of the cable restraint screws on
the DC PDM is 25 lb-in. (33.89 Nm). Use only a torque-controlled screw
driver to tighten screws on the DC PDM cable restraint.
Verify that the power cables are connected correctly, that they are not touching or
12.
blocking access to router components, and that they do not drape where people could
trip on them.
Repeat Steps 3 through
13.
Chapter 9: Grounding and Providing Power to the MX2020 Router
134). Apply between 23 lb-in. (2.6 Nm) and 25 lb-in.
PDM0 , PDM2
feed redundancy for the system to
A/B
12 for the remaining PDMs.
RTN (return) terminal.
(input) terminal.
–48V
, PDM1 , and PDM3 can be powered
, or feed . This configuration
A B
133