CCTV CCTV Power and Cabling Infrastructure 2

Question 1

What is the maximum cable length for a standard Cat6 Ethernet run used for IP CCTV cameras?

Accepted Answer

100 meters

Answer

The IEEE 802.3 standard specifies a maximum segment length of 100 meters for Cat5e/Cat6 Ethernet cable used in IP networks including IP cameras.

Question 2

What device is used to extend IP camera cable runs beyond the 100-meter Ethernet limit?

Accepted Answer

Ethernet switch or media converter

Answer

An Ethernet switch regenerates the signal at each hop, or a fiber media converter can extend the run over much longer distances using fiber optic cable.

Question 3

What is a 'video balun' used for in CCTV installations?

Accepted Answer

Transmitting video over UTP (twisted pair) cable instead of coax

Answer

A video balun converts the unbalanced coaxial cable signal to a balanced signal suitable for transmission over UTP twisted-pair cable.

Question 4

Which grounding issue commonly causes 'hum bars' (horizontal rolling lines) in analog CCTV footage?

Accepted Answer

Ground loop interference between equipment at different potentials

Answer

Ground loops occur when two pieces of equipment are grounded at different electrical potentials, inducing 50/60Hz AC interference into the video signal.

Question 5

What does 'conduit fill ratio' refer to in CCTV cable installation planning?

Accepted Answer

The percentage of a conduit's cross-sectional area occupied by cables

Answer

Conduit fill ratio is the percentage of the conduit's interior cross-section occupied by cables; NEC guidelines typically limit fills to 40% for multiple cables to ensure heat dissipation and cable pull ease.

CCTV - Closed Circuit Television Practice Test

CCTV - Closed Circuit Television Practice Test

CCTV CCTV Power and Cabling Infrastructure 2