Juniper QFX5220, Руководство по оборудованию, Страница: 24 / 247

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QFX5220-32CD power supplies—The QFX5220-32CD switches have one or two power supplies. Each
power supply provides power to all components in the switch. If two power supplies are installed, the
two power supplies provide full power redundancy to the device. If one power supply fails or is removed,
the second power supply balances the electrical load without interruption.
To provide power redundancy to the system, both power supplies must be installed. Connect power
source feed A to one power supply and power source feed B to the second power supply.
CAUTION: Do not connect feed A and feed B to the same power supply input terminal.
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QFX5220-128C power supply modules—The QFX5220-128C switches have two to four power supplies.
The power supply modules are used in 2 + 2 redundancy mode. The system can run on two power
supplies without redundancy. If one power supply fails or is removed, the other power supplies balances
the electrical load without interruption.
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QFX5220-32CD cooling system—The QFX5220-32CD switch models have six fan modules and can
operate with one fan not in operation (5+1 redundancy). If more than one fan module fails and is unable
to keep the QFX5220-32CD within the desired temperature thresholds, chassis alarms occur and the
QFX5220-32CD switch can shut down.
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QFX5220-128C cooling system—This switch model has 12 fans in 6 fan modules. There is one fan out
of the 12 fans for redundancy. This is known as (5x2+1)+1 redundancy). Any additional fan failures cause
the switch to overheat, chassis alarms to occur and shutdown the switch.
QFX5220 Field-Replaceable Units
Field-replaceable units (FRUs) are components that you can replace at your site. The QFX5220 device
FRUs are hot-insertable and hot-removable: you can remove and replace one of them without powering
off the switch or disrupting the switching function.
CAUTION: Replace a failed power supply with a new power supply within 3 minutes of
removal to prevent chassis overheating. The QFX5220-32CD switch continues to operate
with only one power supply running. The QFX5220-128C can operate with only two
power supplies running. For best performance, we advise replacing failed power supplies
and fan modules as quickly as possible to protect against another failure.
Table 4 on page 27 lists the FRUs for the QFX5220 device and actions to take before removing them.
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