Juniper EX4300 Series

NOTE: The DC power supply has ve terminals, two posive terminals labeled V+ and two
negave terminals labeled V–, for connecng the power supply to a dedicated DC power
source by using the DC power source cables labeled posive (+) and negave (–), and one
terminal for connecng the power supply to earth ground (see Figure 69 on page 204). The
V+ terminals are shunted internally together, as are the V– terminals to provide parallel
current path.
8. Connect one end of the grounding cable to a proper earth ground, such as the rack in which the
switch is mounted.
9. Place the grounding lug aached to the grounding cable over the earth ground terminal. The
protecve earth ground terminal on an EX4300 switch, mounted on four posts of a rack, is
accessible through the slot on the mounng bracket on the le side only. If you are unable to
access protecve earthing terminal, you can connect the grounding cable to the earth ground
terminal on the DC power supply.
10. Secure the grounding lug to the protecve earthing terminal with the washers and screws.
11. Dress the grounding cable and ensure that it does not touch or block access to other switch
components.
WARNING: Ensure that the cable does not drape where people could trip over it.
12. Connect each power supply to the power source. Secure power source cables to the power
supplies by screwing the ring lugs aached to the cables to the appropriate terminals by using the
screw from the terminals (see Figure 69 on page 204).
• To connect a power supply to a power source:
a. Secure the ring lug of the posive (+) DC power source cable to one of the + terminals on the
DC power supply.
b. Secure the ring lug of the negave (–) DC power source cable to the – terminal adjacent to
the + terminal that you connected to on the DC power supply.
c. Connect the ground wire to earth ground if the switch is not in a grounded rack. The
protecve earth ground terminal on an EX4300 switch, mounted on four posts of a rack, is
accessible through the slot on the mounng bracket on the le side only. If you are unable to
access protecve earthing terminal, you can connect the grounding cable to the earth ground
terminal on the DC power supply.
d. Tighten the screws on the power supply terminals unl they are snug by using the
screwdriver. Do not overghten—apply between 5 lb-in (0.56 Nm) and 6 lb-in (0.68 Nm) of
torque to the screws.
203