Switch Installation Guide

Chapter 1 Product Overview
Switch Components
1-14
Cisco Catalyst 4900M Switch Installation Guide
78-18350-01
A redundant power supply can be identified and diagnosed by a running system
regardless of its input status. AC and DC supplies are interchangeable.
Power Management Modes
The Catalyst 4900M switch supports the redundant power management mode. In
this mode, if both power supplies are operating normally, each provides from
20/80 to 45/55 percent of the total system power requirements at all times. If one
power supply fails, the other unit increases power to 100 percent of the total power
requirement.