Supplies - Juniper T640 Hardware Manual

T640 Core Router Hardware Guide
Connecting DC Power to a T640 Router with Four-Input 240-A DC Power Supplies
128
General Electrical Safety Guidelines and Electrical Codes for M Series, MX Series, and
T Series Routers on page 324
Site Electrical Wiring Guidelines for M Series and T Series Routers on page 346
You connect DC power to the router by attaching power cables from the DC power sources
to the terminal studs on the power supply faceplates. You must provide power cables
(the cable lugs are supplied with the router).
To connect the DC source power cables to the router, follow this procedure for each
power supply:
Ensure that the voltage across the DC power source cable leads is 0 V and that there
1.
is no chance that the cable leads might become active during installation.
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 an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect
2.
the strap to one of the ESD points on the chassis.
Switch the circuit breakers on the power supply faceplate to the
3.
Remove the clear plastic cover protecting the terminal studs on the faceplate.
4.
Remove the nut and washer from each power terminal stud. If no washers and nuts
5.
are already installed, they should be in the accessory box.
Attach the lugs on the DC source power cables to the terminal studs. Secure the cable
6.
lugs to the terminal studs, first with the washers, then with the nuts.
Attach the positive (+) DC source power cable lugs to the
a.
Attach the negative (–) DC source power cable lugs to the
b.
Using a 7/16-in. (11 mm) nut driver, tighten the nuts (see Figure 74 on page 129). 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 in-lb (5.0 Nm).
and to indicate
(+) (–)
position (
OFF
(return) terminals.
RTN
(input) terminals.
–48V
Copyright © 2010, Juniper Networks, Inc.
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