Cat5e/Cat6 and baluns
Balun is the abbreviation of balance+unbalance. A video balun is one of an important accessories that converts between a balanced signal and an unbalanced signal.
The reason why use video baluns? Video baluns, also known as CAT5 /CAT6 baluns, enable security installers to utilize CAT5/CAT6 cable running video (and optionally power) for CCTV video cameras. A video balun is positioned on both ends of the CAT5/CAT6 cable run and uses one of the the twisted pairs from the CAT5 cable to transfer the video from the camera to a DVR or monitor. There are also multi-camera baluns that could use the four twisted pairs in CAT5/CAT6 to transfer the video for up to 4 cameras.
The majority of security camera installers are familiar with using RG59 Siamese coax cable for CCTV, as this is actually the industry standard cable and also permits installers to run both the video from the camera and power to the camera by using a single cable run. There are versions of video baluns that also support running power to CCTV video cameras in addition to the video. These are some of the most common reasons that a security installer would choose to use CAT5/CAT6 cable rather than RG59 for a CCTV application.
The majority of locations have CAT5/CAT6 cable pre-run for network infrastructure and installer can use the existing cable network.
Solves the short range maximum video transmission distance via RG59 (coaxial cable), this offers much more long range distance for video transmission, exceeds 700ft.
Cost-effective solution. RG59 coaxial cable is more expensive than Cat5/CAT6 cable.
Video Balun Connectors
Active Video Balun
Active video baluns include a power supply and function as an amplifier so that cable distances can be increased beyond 1200 ft (the limit for passive baluns). In addition, An active balun receiver can be utilized on the DVR or monitor side of the cable with a passive balun on the video camera side to enhance maximum effective distance to 2000 feet.
When an active transmitter balun and active receiver balun are utilized with each other, the effective range of the cable will increase to 4000 ft for color cameras and also 5000 feet for monochrome. The below diagram illustrates the wiring used when installing active video baluns. Please note that power is needed for both the transmitting and receiving unit.
Passive video baluns
Passive video baluns are not powered and support cable distances up to 1200 ft. These baluns use only one of the twisted pairs in the Cat5 cable. The CAT5/CAT6 is attached to the baluns on each end using screw terminals or some other connection types. The balun has a BNC connector that gets linked to the video camera on one end and a DVR or monitor on the other. Please see the below wiring diagram, which illustrates this.
Video baluns with power
Video baluns with power support running low voltage power to CCTV video cameras along with transferring the video signal. For baluns which also supply power to video cameras, one of the twisted pairs from the CAT5 cable is used for video and 2 pairs are used for power.
Installers attach one pair for the positive and one pair for the negative power leads. Additionally, there are video + power baluns that implement RJ-45 connectors instead of the cable terminals, and even several versions which support audio too. Some installers prefer this, especially when using pre-made network cables with the RJ-45 ends already attached.
An essential note: the distance that power is not able to be run is much less than video and is still restricted to the voltage and also gauge of cable being used. 12V DC usually begins to drop after 200 feet. The below video demonstrates how to use passive video baluns with power.
Multi-camera video baluns can work with several cameras and allows each twisted pair of a Cat5/CAT6 to be used for one camera, effectively allowing users to run video for up to four CCTV cameras over a single Cat5/CAT6 cable. Check below diagram illustration for how multiple camera video balun is wired.