BY DEBORAH O’MARA
THE POTENTIAL OF POWER OVER ETHERNET
(PoE) continues to grow, creating new installation opportunities for electrical contractors doing
integrated systems work.
An established and often specified media, Ethernet cabling and
connectivity continue to be deployed for transmission of information,
physical security and data. PoE offers the ability to deliver power efficiently and effectively over the existing infrastructure, providing a
substantial cost and labor savings. It also continues to advance with
the times, parlaying its increasingly robust power capabilities to better
leverage integrated systems installations.
What is PoE?
PoE uses an existing local area network (LAN) to transmit low-voltage
direct current (DC) power and data, eliminating the need for additional
power supplies or electrical wiring. Therefore, PoE enables installers to
power an end device, such as a camera or access control reader, without
running a second cable. It offers significant labor and hardware savings
for contractors and their customers, especially in locations where digging
and trenching is difficult or restrictive.
The Institute of Electrical and Electronics Engineers (IEEE) has two es-
Times have changed. Many more devices that require additional power
tablished PoE standards, and a third is under development. The IEEE 802.3af
PoE standard in 2003 opened the gate for equipment manufacturers to
produce and leverage standards-based products that optimize the technol-
ogy. Under IEEE 802.3af, 15. 4 watts (W) of power were available for each
powered device, which was adequate for many in-the-field PoE applica-
tions at the time.
have hit the market. A good example is outdoor surveillance cameras with
pan-tilt-zoom (PTZ) functionality and those with heaters and blowers used
to offset extreme cold and hot temperatures.
and product options