Cisco WS-C2980G-A Software Guide - Page 426

Understanding How Power Management Works on the Catalyst 4006 Switch Chapter 28 Power Management Understanding How Power Management Works on the Catalyst 4006 Switch These sections describe how to manage power for the Catalyst 4006 switch. Note For information on power management for the Catalyst 4500 series switches, see the "Understanding How Power Management Works on the Catalyst 4500 Series Switches" section on page 28-1. The power management feature for the Catalyst 4000 series switches support a limited module configuration on a reduced number of power supplies. The Catalyst 4000 series switch chassis supports only the 400 W AC, 400 W DC, and 650 W DC power supplies and allows you to use AC-input and DC-input power supplies in the same chassis. In systems with redundant power supplies, both power supplies should have the same wattage. If you use a 400 W power supply and a 650 W power supply, the switch acts as if there were two 400 W power supplies. For more information, refer to the Catalyst 4000 Series Switch Installation Guide. Understanding Power Redundancy The Catalyst 4006 switch contains holding bays for up to three power supplies. You need two primary power supplies to operate a fully loaded Catalyst 4006 chassis. You can set the power redundancy to two primary plus one redundant power supply (2+1 redundancy mode) or to one primary plus one redundant power supply (1+1 redundancy mode). The 1+1 redundancy mode might not support a fully loaded chassis. If your switch has only two power supplies and is in 2+1 redundancy mode (the default mode), there is no redundancy. You can create redundancy with only two power supplies by setting the power redundancy to operate in 1+1 redundancy mode (one primary plus one redundant power supply). However, 1+1 redundancy does not support all configurations. The modules for the Catalyst 4006 switch have different power requirements; some switch configurations require more power than 1+1 redundancy mode (a single power supply) can provide. In those configurations, redundancy requires three power supplies. You can use the 1+1 redundancy mode in these hardware configurations: • One Catalyst 4006 chassis with a WS-X4013 supervisor engine with two 400 W power supplies (in 1+1 redundancy mode) and four WS-X4148-RJ or WS-X4148-RJ21 modules • One Catalyst 4006 chassis with a WS-X4013 supervisor engine with two 650 W power supplies (in 1+1 redundancy mode) and five WS-X4148-RJ or WS-X4148-RJ21 modules Although other configurations are possible, we do not recommend that you use them without carefully considering the power usage of the system. For example, other similar and possible configurations may consist of four modules that consume less power, and the total module power usage does not exceed the absolute maximum power usage for the system. The supervisor engine uses 110 W and the fan tray uses 25 W. The total load for the modules, the supervisor engine, and the fan cannot total more than the power that is supplied by the power supply. The 1+1 redundancy mode might not support a fully loaded chassis. You may need to leave one slot of the chassis empty. An attempt to use five modules risks an oversubscription of available power. 28-6 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 78-15486-01