Juniper ACX4000 Quick Start Manual page 15

Copyright © 2015, Juniper Networks, Inc.
Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect
1.
the strap to one of the ESD points on the chassis. For more information about ESD,
see the
ACX4000 Universal Access Routers Hardware Guide
Switch off the dedicated customer site circuit breakers. Ensure that the voltage across
2.
the DC power source cable leads is 0 V and that there is no chance that the cable
leads might become active during installation.
Remove the plastic cover protecting the terminal on the faceplate.
3.
Verify that the DC power cables are correctly labeled before making connections to
4.
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 return DC cables to chassis ground:
For –48V and –60V:
a. The cable with very large resistance (indicating an open circuit) to chassis ground
is the DC input cable (
b. The cable with very low resistance (indicating a closed circuit) to chassis ground
is the return cable ( +
For +24V:
a. The cable with very low resistance (indicating a closed circuit) to chassis ground
is the DC input cable (
b. The cable with very large resistance (indicating an open circuit) to chassis ground
is the return cable (
+
Remove the screws and flat washers from the terminals.
5.
Secure each power cable lug to the terminal with the flat washers and screw (see
6.
Figure 8 on page 16). Apply between 8 lb-in. (0.9 Nm) and 9 lb-in. (1.02 Nm) of torque
to each screw. Do not overtighten the screw. (Use a number 2 Phillips screwdriver.)
a. Secure the positive DC source power cable lug to the return (
b. Secure the negative DC source power cable lug to the input (
CAUTION: Ensure that each power cable lug seats flush against the surface
of the terminal block as you are tightening the screws. Ensure that each
screw is properly threaded into the terminal. Applying installation torque
to the screw when the screw is improperly threaded may result in damage
to the terminal.
CAUTION: The maximum torque rating of the terminal screws on the DC
power supply is 9 lb-in. (1.02 Nm). The terminal screws may be damaged
if excessive torque is applied. Use only a torque-controlled driver to tighten
screws on the DC power supply terminals. Use an appropriately sized
driver, with a maximum torque capacity of 9 lb-in. or less. Ensure that the
Connect DC Power to a DC-Powered ACX4000 Router
).
–
).
).
–
).
.
) terminal.
+
) terminal.
–
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