Dell EMC Configuration Guide for the S3100 Series 9.14.2.4

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Power over Ethernet (PoE)

The PoE feature supports electrical power and transmission of data on Ethernet cabling. A single cable can provide both data connection and electrical power to the attached devices such as wireless access points or IP cameras.

Power over Ethernet (PoE), as described by IEEE 802.3af specifies that a maximum of 15.4 watts can be transmitted to Ethernet devices over the signal pairs of an unshielded twisted pair (UTP) cable. PoE is useful in networks with IP phones and wireless access points because separate power supplies for powered devices (PD) are not needed. Power over Ethernet Plus (PoE+), as described by IEEE 802.3at, supplies a maximum of 30.0 watts. This provides sufficient power for devices that require 12.95W to 25.5W, such as pan-tilt-zoom (PTZ) security cameras, 802.11n Wi-Fi Access Points, and IP phones with advanced features, such as video conferencing.

The following table describes the classes of powered devices defined by IEEE 802.3af and 802.3at:

Table 1. Classes of Powered DevicesTable listing the classes of powered devices.
Class	Power Range (Watts)	Classification Current (MA)
0	0.44 to 12.95	<5.0
1	0.44 to 3.84	10.5
2	3.84 to 6.49	18.5
3	6.49 to 12.95	28
PoE+ Only
4	12.95 to 25.5	40

NOTE Class 4 is meant for IEEE802.3at compliant devices which require >12.95 Watts. Class 4 devices will be supported by PoE card, but the maximum power is limited to 15W.

In the S3100 series, the platforms S3124P and S3148P support PoE/PoE+ with the following power options:

S3124P PSU: 715W, DC output 54V/13.24A or 1100W, DC output 54V/20.37A
S3148P PSU: 1100W, DC output 54V/20.37A,