One of the most common problems we encounter with cctv systems is interference on cameras. This can be caused by several sources. Improperly run video cable that is run parallel to power lines, over fluorescent lights, or near electric motors are common culprits. Another thing to consider is ground loop interference. A ground loop, or 60 cycle bars, appear as rolling horizontal bars on the video screen. This can be a result of the camera and dvr or monitor using different grounds and introducing AC voltage into the video signal. Coax connections touching each other or metal frames, mounting cameras on metal buildings are usually the first reason that we see ground loops occur. Here are a few ways to avoid ground loops before they occur. If you are mounting cameras on a metal building, mount a block of wood or another type of non-conductive material to the building, and then mount your camera to the block. This will isolate the camera from grounding to the building. Also, if you have several coax connections or if you are using Cat5 with baluns, be sure and insulate the connections with heat shrink or electrical tape. Finally, there are in-line ground loop isolators that remove interference on the coax line. Taking these simple precautions will save you from trips back and forth to diagnose a pesky problem that help you keep happy customers.
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