Four months ago, a customer called us with a video signal noise problem on his CCTV SYSTEM. Apparently, he had changed the cabling of his camera cabling from coaxial to Cat6 (Ethernet). The technician, however, did not separate the power signal from the video signal in the new installation.
Here is the lesson he had to learn the hard way when it came to running cable in parallel with electrical cables.
Data cabling used “UTP” — unshielded twisted pairs — to achieve its goals. The magnetic field generated by the low voltage running through the cable is a critical component of the communications chain. When you run this unshielded cabling in parallel with electrical cables, that magnetic field is disrupted and the communication becomes noisy and garbled. In many cases, transmissions will simply not make it from Point A to Point B. In other cases, transmission rates will slow to a crawl as communications are constantly retried.
If you have to go near electrical power lines, cross them in perpendicular instead.
And now comes another story: Way back in the late 90s, I was asked to look into why a newly installed coaxial cable wasn’t working. It was a building-to-building connection between two buildings that were very close to one another. Upon arriving at the site, I looked up and saw that the coaxial cable was twisted around the overhead electrical cabling that ran between the two buildings. Needless to say, it was easy to identify the cause of the problem.