Juniper ACX500 Hardware Manual page 161

Copyright © 2016, Juniper Networks, Inc.
To connect the power cables:
Switch off the dedicated customer-site circuit breakers. Ensure that the voltage across
1.
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 clear plastic cover protecting the terminal on the faceplate.
2.
Verify that the DC power cables are correctly labeled before making connections to
3.
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 DC cables to chassis ground:
Locate the power cables, which should have a plug appropriate for your geographical
location. See the "ACX500 DC Power Specifications" on page
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 return cable ( –
b. The cable with very large resistance (indicating an open circuit) to chassis ground
is DC input cable ( ).
+
Remove the screws and flat washers from the terminals.
4.
Secure each power cable lug to the terminal with the flat washers and screw (see
5.
Figure 61 on page 142). Apply between 8 lb-in. (0.9 Nm) and 9 lb-in. (1 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 improperly threaded might 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 Nm). The terminal screws might 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
Chapter 14: Providing Power to the ACX500
).
–
).
).
84.
) terminal.
+
) terminal.
–
141