Juniper ACX1000 Quick Start Manual page 17

Table 1: ACX Series DC Power System Input Voltage
Nominal Voltage
–48
–60
1. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to
one of the ESD points on the chassis. For more information about ESD, see the
ACX1100 Universal Access Routers Hardware Guide
2. Switch off the dedicated customer site circuit breakers. Ensure that the voltage across the DC
power source cable leads is 0 V and that there is no chance that the cable leads might become
active during installation.
3. Remove the clear plastic cover protecting the terminal on the faceplate.
4. Verify that the DC power cables are correctly labeled before making connections to 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 (+).
5. Remove the screws and flat washers from the terminals.
6. Secure each power cable lug to the terminal with the flat washers and screw (see
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 (+) terminal.
b. Secure the negative DC source power cable lug to the input (–) terminal.
(Continued)
Specification
Operating range: –39 to –56 VDC
Operating range: –39 to –72 VDC
.
ACX1000 and
Figure 10 on page
14