WARNING: Ensure that the power cables do not block access to device components or drape
where people can trip on them.
7. Connect each power supply to the power sources. Secure power source cables to the power supplies by screwing the
ring lugs attached to the cables to the appropriate terminals by using the screw from the terminals (see Figure 15).
We’ve designed the QFX5120-48Y or QFX5120-48T switch to operate with a DC power supply that has a single,
nonredundant, feed input. For source redundancy, you must install two DC power supplies in the QFX5120-48Y or
QFX5120-48T switch; connect source (A) to one power supply and connect source (B) to the second power supply.
This configuration provides the commonly deployed A/B feed redundancy for the system.
The terminal block of the power supply has four terminals labeled V+, V+, V–, and V– for connecting DC power source
cables labeled positive (+) and negative (–). The V+ terminals are shunted internally together, as are the V– terminals.
CAUTION: The connection between each power source and power supply must include a circuit
breaker.
Do not connect two sources to a single power supply because doing so can potentially cause
circulating current in feed wires whenever there is any difference in the voltage of the two sources.
a. Secure the ring lug of the positive (+) DC power source cable to the V+ terminal on the DC power supply.
b. Secure the ring lug of the negative (–) DC power source cable to the V– terminal on the DC power supply.
c. Tighten the screws on the power supply terminals until snug using the screwdriver. Do not overtighten; apply
between 5 lb-in. (0.56 Nm) and 6 lb-in. (0.68 Nm) of torque to the screws.
CAUTION: The V+ terminals are shunted internally together, as are the V- terminals. The same
polarity terminal can be wired together from the same source to provide an additional current path
in a higher power chassis. Do not connect the terminals to different sources.
15
To Next Page
Loading...
