Juniper QFX5220, Hardware Manual, Page: 143 / 247

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 in-lb (0.56 Nm) and 6 in-lb (0.68 Nm) of torque to the screws.
WARNING: Ensure that the power cables do not block access to device components
or drape where people can trip on them.
8. Replace the terminal block cover.
9. Close the input circuit breaker.
NOTE: The switch powers on as soon as power is provided to the power supply. There is no
power switch on the device.
10. Verify that the IN and OUT LEDs on the power supply are lit green and are on steadily.
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