Cisco Systems 3700 Series manual Power Supply Options, Internal -48 V Telephony Power Modules

Chapter 1 Overview of Cisco 3700 Series Routers

Power Supply Options

Power Supply Options

Table 1-3lists the power supply options supported by Cisco 3700 series routers. Depending on the configuration specified when you placed your order, your router may not support all of these options.

Table 1-3	Power Supply Options for Cisco 3700 Series Routers
Power Supply Option		Cisco 3725	Cisco 3745
AC input power		Yes	Yes
DC input power		Yes	Yes
–48-V telephony power module to provide inline power to IP phones		Yes	Yes
Dual hot-swappable power supplies		No	Yes1
Compatible with Cisco Redundant Power System		Yes	Yes

1.Because of increased power consumption in high-temperature environments, a fully loaded Cisco 3745 router requires both power supplies when ambient temperature exceeds 104°F (40°C). Cisco 3745 routers operating under these conditions do not support the online replacement of power supplies.

Internal –48 V Telephony Power Modules

Cisco 3700 series routers provide inline power to IP phones connected to the router through Ethernet switch network modules. This power is supplied by special –48 V modules that connect directly to the chassis power supplies in Cisco 3725 and Cisco 3745 routers. A single –48 V power module meets the power needs of up to 36 IP phones. A Cisco 3745 router with two –48 V power modules installed provides redundant power for up to 36 IP phones. Figure 1-5and Figure 1-6show the –48 -V power modules as they appear when installed in Cisco 3700 series routers.

Cisco 3700 Series Routers Hardware Installation Guide

OL-2180-08 1-9