Power Over Ethernet - Cisco CAtalyst 4500 Series Installation Manual

Chapter 1 Product Overview
System Architecture
2800 W AC, 4200 W AC or 1400 W DC) also provide a –48 V circuit (shown as
a dashed line) to PoE-enabled switching modules, which is then available to the
powered device connected to the switching module.
The Supervisor Engine II-Plus TS has internal DC-to-DC converters that use the
Note
12 V circuit to provide PoE to powered devices connected to the Supervisor
engine only. If your system has a Supervisor Engine II-Plus TS in slot 1, you still
need a PoE-enabled power supply to provide PoE to the other slots.
All Catalyst 4500 series switches support dual power supplies, configurable as
combined mode or redundant mode. In combined mode, the switch has available
the combined rated wattage of both power supplies, less some expected efficiency
loss. In redundant mode, one power supply provides power to the system and the
other supply is on standby should there be a failure in either the power supply or
the input voltage source it is connected to.

Power over Ethernet

The Cisco Catalyst 4500 Series switches support the Cisco pre-standard and
802.3af standard for PoE on 10/100 or 10/100/1000 ports, enabling customers to
support telephones, wireless base stations, video cameras, and other appliances.
PoE makes it possible to place devices in unique locations without having to
provide new outlets and costly electrical circuits. PoE also enables businesses to
isolate critical devices on a single power system so that the entire system can be
supported by uninterruptable power supply (UPS) backup.
All new Cisco Catalyst PoE line cards can support 15.4 W of power per port
simultaneously. Not only do the cards support the IEEE standard, including the
optional power classifications, but the Cisco pre-standard power implementation
is also supported to help ensure backward compatibility with existing Cisco
powered devices. The cards are compatible with any chassis and supervisor
engine. Most importantly, the Catalyst 4500 series switch has the power supplies
and accessories to support 15.4 W per port on every port simultaneously in any
fully loaded chassis. (This requires an external power shelf or a 4200 W dual-input
power supply.)
Catalyst 4500 Series Switches Installation Guide
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