Look-in to CCTV Security Cameras
Our Los Angeles based security camera system company with Total Connect Video Services and professional installation let you effortlessly look in on any surveillance camera installed location via laptops, PCs and compatible mobile devices whether you’re across the street in Los Angeles or across the country.
However there are many factors to consider the correct system and have the surveillance system professionally installed.
We can assist you in selecting the best security cameras system and our installation services throughout Southern California including Los Angeles, Orange County Ca, Apple Valley, Ventura County, West Hills, San Bernardino County and now Nationwide.
Here are some of the factors involved in proper selection and installation:
Use of the correct type of coax for security cameras system and installing it within It's distance boundaries, and limiting splices will provide the monitoring point with a good quality image
Use of improper coax (not designed for CCTV), extending recommended coax during the surveillance system installation
operational distances, and poor splices (including BNC T's), can result in poor, weak, and distorted video, and possible loss of sync.
Lack of termination causes the security video system signal to reflect or bounce back in the coax, creating a ghosting effect.
The undermanaged signal from the cameras may overdrive
the monitor which could cause distortion Double termination weakens the signal.
This will cause a faded signal. If the signal strength is low, due to long runs(etc.), the video security monitor could lose the sync signal required to lock onto the security camera picture.
Monitor at camera site displays correct image.
At the control room the picture is distorted due to the difference In AC grounds of the surveillance camera and the security monitor
Ground loops can cause the picture to tear, bend, cause dark lines to appear across the screen, and/or loss of sync and video. The amount of distortion Is dependent upon
the degree of the ground indifference, and the video signal strength.
Security Camera Wiring and SETUP— Ground Loops
As defined, a ground loop is an AC current that is on the shield, or ground, of the video cable. This AC current will affect the appearance of the displayed security camera video.
When the video signal is transported via coax cable, the potential for a ground loop exists. This coax utilizes the center conductor for the video information. The shield of the coax is used as a ground reference for this video signal. Under normal operations, the video reference (ground) is a 0 volt level with the video 'riding' above it.
When AC Is applied to this ground reference, the flat ground reference level will fluctuate above and below the 0 volt ground point. This will cause video distortion to occur.
The effects of a ground loop in security camera system installation are any one, or a combination of, slight bending of the video image, severe tearing, and/or vertical roll. Total loss of synchronization and usable picture could result from extreme cases of ground loops.
The degree of the effect will be governed by several factors: the level or amount of AC on the cable and the level of video signal from the camera or video equipment The greater the level of AC, the greater the distortion. Low levels of AC on the ground may not show apparent with a strong video signal. A weak signal (low sync) will be more susceptible to the ground loop conditions.
CAUSES FOR GROUND LOOPS
Typically, a ground loop condition is possible any time that a camera's power is obtained from a different source then that of the security camera monitor. An imbalance between grounds may be present. These two ground points are tied together by the coax, resulting In the AC current flow through the shield causing the video signal to 'float' on this AC level. Different ground potentials may be induced into the video at any contact to ground by the coax cable, such as splice points and/or Junction boxes.
DETECTION and REMOTE VIEW
The presence of a ground loop can be seen when viewing the signal on a scope. The normal level response of .
signal will show a wavy presentation. This wave is the AC distorting the video signal. If a scope is not available for this measurement, an AC voltmeter may be used. See the following procedure.
1. Disconnect the coax at the security camera system monitor.
2. With an AC volt meter, connect one lead to the monitor ground. Connect the other lead to the shield of the coax or BNC connector.
3. With the meter on the AC volt setting, measuring AC volts present.
4. In theory, the ground of the security camera system monitor and the ground of the coax should be equal and a 0 voltage reading should be seen. Any voltage level present, typically as low as 50 mV, is a potential ground loop condition.
Elimination: Ground Isolation Transformer This transformer effectively eliminates the ground loop potential by isolating the grounds. Note: Any contact to ground after the ". G2 7-- could result in another potential ground indifference. For this reason, the - should be located as dose to the security system monitor as possible.