Juniper EX Series Complete Hardware Manual page 106

Complete Hardware Guide for EX 3200 and EX 4200 Switches
WARNING: Ensure that the power cables do not block access to switch components
or drape where people can trip on them.
6.
84
Connecting DC Power to an EX 3200 or EX 4200 Switch
Connect the power supplies to the power sources. Secure power source cables
to the power supplies by screwing the ring lug attached to the cable to the
appropriate terminal by using the screw from the terminal (see
Figure 46 on page 85).
To connect a power supply to a power source:
Leave the jumpers on the power supply terminals in place.
a.
Secure the ring lug of the positive (+) DC power source cable to the A+
b.
or B+ terminal on the DC power supply.
Secure the ring lug of the negative (–) DC power source cable to the A–
c.
or B– terminal on the DC power supply.
Tighten the screws on the power supply terminals until snug using the
d.
Phillips (+) screwdriver, number 2. Do not overtighten—apply between
8 lb-in. (0.9 Nm) and 9 lb-in. (1.02 Nm) of torque to the screws.
If you have a second installed power supply, connect it in the same way you
did the first.
To connect one power supply to two power sources:
Remove the jumpers on the power supply terminal block.
a.
Secure the ring lug of the positive (+) DC power source cable from the
b.
first DC power source to the A+ terminal on the first DC power supply.
Secure the ring lug of the negative (–) DC power source cable from the
c.
first DC power source to the A– terminal on the first DC power supply.
Secure the ring lug of the positive (+) DC power source cable from the
d.
second DC power source to the A+ terminal on the second DC power
supply.
Secure the ring lug of the negative (–) DC power source cable from the
e.
second DC power source to the A– terminal on the second DC power
supply.
Tighten the screws on the power supply terminals on both the power
f.
supplies until snug using the Phillips (+) screwdriver, number 2. Do not
overtighten—apply between 8 lb-in. (0.9 Nm) and 9 lb-in. (1.02 Nm) of
torque to the screws.