Cisco Catalyst 4500e Series Installation Manual page 50

System Architecture
All PoE switching modules can distinguish an IEEE or Cisco prestandard powered device from an
unpowered network interface card (NIC) to ensure power is applied only when an appropriate device is
connected. With a Cisco PoE network, administrators can depend on a robust network that is safe to
deploy and simple to maintain.
Deploying PoE on the Cisco Catalyst 4500 E-series
When the switch is properly configured, implementing PoE is easy when it is used with a Cisco powered
device that supports Cisco Discovery Protocol. All PoE switching modules automatically detect an
attached powered device the moment it is installed. Also, the switch returns unused port power to the
system power budget for use by other devices because it supports the IEEE802.3af optional power
classifications.
The Cisco Catalyst 4500 E-series offers internal power supplies and external power devices for multiple
deployment scenarios. These scenarios include small and large deployments in AC or DC environments
for data-only configurations, and scalability of up to 15.4 W per port for PoE configurations.
The switches share a common power supply form factor. Each Cisco Catalyst 4500 E-series chassis is
designed for 1 + 1 power protection while meeting the needs of PoE demands. In addition to power
resiliency, the Cisco Catalyst 4500 E-series includes 1 + 1 supervisor-engine redundancy (Cisco Catalyst
4507R-E and Catalyst 4510R-E only) and software-based fault tolerance. Integrated resiliency in both
hardware and software minimizes network downtime, helping ensure workforce productivity, portability,
and customer success.
All available Cisco Catalyst 4500 E-series compatible power supplies can be used for data-only
deployments, which typically require just a few hundred watts. For deployments that dictate support for
PoE power, Cisco offers several options.
The Cisco Catalyst 4500 E-series offers several internal supplies: 1000 W AC (data only), 1400 W AC
(data only), 1300 W (data and PoE), 1400 W DC (data and PoE), 2800 W (data and PoE), and 4200 W
AC (data and PoE). When more than 4200 W of redundant data and PoE are required for a Cisco Catalyst
4500 E-series chassis in an AC-powered environment, Cisco offers an external AC power shelf that
houses two 2500 W AC power supplies. When two power shelves are combined, they can produce
7500 W—the remaining 2500 W supply can be used for N + 1 protection.
The Cisco Catalyst 4500 E-series has two DC power options; one is optimized for data-only deployments
in service provider central offices (part number PWR-C45-1400DC), and the other is used for
high-power PoE deployments (part number PWR-C45-1400DC-P).
Cisco Catalyst 4500 Series External AC Power Shelf and
1400 W DC Power Supply with Integrated Power Entry Module
The external AC power shelf must be used in conjunction with the 1400 W DC power supply. In addition
to providing power for the chassis, fans, and non-PoE switching modules, the 1400 W DC power supply
contains a power entry module (PEM). The PEM is used to pass additional power to the chassis
backplane, power demanded by the PoE switching modules. The chassis power trace used for PoE is
independent from the one used by the supervisor engine(s), fan tray, and backplane components. The
1400 W DC power supply can accept up to 7500 W DC for data and PoE applications. Up to 1400 W can
be dedicated for data (supervisor engine, fan tray, etc.), while the remaining power is passed through via
the PEM and is used for PoE.
When only one external AC power shelf is used (with two 2500 W AC power supplies), it provides the
1400 W DC power supply with 5000 W of DC power in total. When two AC power shelves are strapped
together, the switch can provide up to 7500 W of DC power (3 + 1 redundant).
Catalyst 4500 E-Series Switches Installation Guide
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Chapter 1 Product Overview
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