The Long and Short of PoE

Powering security cameras through the same cable used to transmit data and video is one of the greatest benefits of IP cameras over network cabling. Ease of installation with one pull, one cable and also cost reduction by limiting AC power at the device...


Together this cable with media converters creates a PoE extender system. The powered media converter, or power injector (a midspan device), located in the TR injects both the power from the DC source and the data from the Ethernet switch. The composite cable assembly attaches to the injector through fiber LC connectors and screw terminals for the copper/power conductors. The total distance is limited by the power provided through the active media converter on the termination side as well as the gauge of the copper. The more power needed, the thicker the gauge. Distances up to 3,850 feet between media converters can be achieved.

The remote module is a passive media converter that converts the cable assembly to an RJ-45, IEEE 802.3af compliant output. An additional 328 feet (100 meters) of horizontal UTP cable may be added from the remote module to increase the total distance beyond 4,000 feet.


Figure 2: PoE Extender system with a composite copper/fiber cable. The media converter and the camera on the device end do not require an AC receptacle as they are powered through the cable.

PoE is becoming an integral part of IP devices, not only for security cameras, but access control, HVAC controls and other building automation systems that are becoming attached to the network. Make sure that the cable choices selected today will accommodate applications of tomorrow.



Pull quote:

“In long-distance scenarios where local power for the media converter is not feasible or accessible a composite copper/fiber cable within the same sheath can be used.”



Carol Everett Oliver RCDD, ESS Specialist is a Marketing Analyst for Berk-Tek, a Nexans Company. She can be reached at