HD-TVI Cameras vertical line noise, scrolling horizontally

[avvora 0]

I have installed three 4 channel systems with 4 cameras and all of them have had vertical lines scrolling across the screen horizontally. It is not present (or not noticeable) when just one camera is connected to the DVR, but once you start adding more cameras it gets worse. I feel like it must be a ground loop problem because even if one of the baluns touches any metal surface on the DVR the lines come back, you don't even have to connect the camera, just let the metal surface of the BNC connector touch clean metal anywhere on the DVR - Boom! Lines come back. I fixed it on one of the jobs by powering each camera with its own dedicated 12v plug in AC/DC adapter. However this did not fix the problem with today's install. I spent hours troubleshooting the problem. I even powered two of the cameras locally with its own 12v battery so no power was being sent over the cat5 at all. The lines still didn't go away! If there are four cameras connected to the DVR it's really bad but if you unplug the power source from any three out of the four cameras, the remaining camera will have a clean picture. All four cameras tested individually had a clean picture when connected by itself. It's got to be ground loop interence right? But if I install ground loop isolators, what type should I use and should they go on the camera side or the DVR side, or both? Also I see Hikvision makes an HD-TVI ground loop isolator that goes on the power wire, not the video. I wonder if I should but ground loop isolators on both the video and power...this could start getting expensive! This is frustrating because it's holding me up from getting paid on this particular job, but at the same time I'm interested to find the cause of this problem. The symtom was the same on all three systems, all using Cat5e and baluns. Any suggestions or similar experiences? Please share!

[cctvinstallation 0]

To make sure it is not the DVR can you connect a a known good channel to that connection? That will rule out the DVR and leave something going on with the cabling. Basically change connections on back of DVR. I am am thinking your ground on the connection in question could be bad.

 

 

 

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[Magic of Philly 0]

I have the solution to your problem.

 

This issue I saw it when I first began doing CCTV installations, back in the days of the D1/700 TVL world I was using cameras that was all metal enclosure and the camera's circuitry was grounded to the camera's metal frame. When i finished hooking up all the cameras and then I plugged in the cameras to the back of the DVR there was some very bad ground loops, no matter what I did it did not went away, then I did a few test with my volt meter configured for continuity (it beeps when you short both the probes together), I went up to one of the cameras, disconnected the BNC and Power connectors and place one probe of my multi meter to the metal frame of the building where the camera was placed at and the other probe to the outer metal BNC head and lo and behold the meter beeped. So I have just found out the source of the ground loop problem and began thinking of a way to isolate the cameras from the building' outer metal, went to home depot and purchase a few non-conducive electrical boxes, installed those boxes, did another continuity test and didn't beep this time, hooked up the cameras and everything was ok, no lines, videos looked perfectly fine. Took me an extra day of work on the project to come to resolution.

 

Another solution if you cant find a non-conducive box because most boxes are conducive is to use the plexy glass trick, keep the original metal electrical box you installed, but instead of using the cover plate that came with the electrical box where you drilled four holes where the cameras are mounted, you cut a plexy glass (better if the plexy glass is coated with black) to the same dimensions of the electrical box cover, then with metal drill bit you drill the holes where the mounting screws will go to for fixing to the box purposes and the drill additional holes (3 or 4) to mount the cameras in the center, cover all exposed metals from the BNC head with black tape fully, you dont want the bare metal of the BNC head to touch the inner metal of the electrical box otherwise the ground loop will return, then use 1" screws so that it will not go too deep in to not risk touching the inner layer of the electrical box otherwise the ground loop will return, plug in the DC to DC port of Camera again cover with black tape any exposed DC wiring you might have left, you dont want those touching any metal portions of the electrical box, install the cameras, repeat for all other cameras, now you have a perfectly isolated from that uncommon ground all cameras and you shall not get any ground loops anymore.

 

Additional info:

 

If you install the LCD monitor in a far away room or other location or even in an outlet connected to a different phase than the one where the DVR and Cameras are connected, you might get the ground loop syndrome again and those lines might return, resolution of this, connect the monitor to the same circuit where the DVR and all the cameras belong to. Ideally, you want to use CCTV Power Distribution Box (5 Amps for a 4 Camera install, 10 Amps for a 8 cameras install, 20 Amps for a 16 Cameras install, etc assuming each camera wont consume more than 1 Amps tops, and each terminal would be fused at 1 Amps and each terminal on the 20 Amps version is fused at 1.6 amps).

[gsal 0]

I have the solution to your problem.

 

This issue I saw it when I first began doing CCTV installations, back in the days of the D1/700 TVL world I was using cameras that was all metal enclosure and the camera's circuitry was grounded to the camera's metal frame. When i finished hooking up all the cameras and then I plugged in the cameras to the back of the DVR there was some very bad ground loops, no matter what I did it did not went away, then I did a few test with my volt meter configured for continuity (it beeps when you short both the probes together), I went up to one of the cameras, disconnected the BNC and Power connectors and place one probe of my multi meter to the metal frame of the building where the camera was placed at and the other probe to the outer metal BNC head and lo and behold the meter beeped. So I have just found out the source of the ground loop problem and began thinking of a way to isolate the cameras from the building' outer metal, went to home depot and purchase a few non-conducive electrical boxes, installed those boxes, did another continuity test and didn't beep this time, hooked up the cameras and everything was ok, no lines, videos looked perfectly fine. Took me an extra day of work on the project to come to resolution.

 

Another solution if you cant find a non-conducive box because most boxes are conducive is to use the plexy glass trick, keep the original metal electrical box you installed, but instead of using the cover plate that came with the electrical box where you drilled four holes where the cameras are mounted, you cut a plexy glass (better if the plexy glass is coated with black) to the same dimensions of the electrical box cover, then with metal drill bit you drill the holes where the mounting screws will go to for fixing to the box purposes and the drill additional holes (3 or 4) to mount the cameras in the center, cover all exposed metals from the BNC head with black tape fully, you dont want the bare metal of the BNC head to touch the inner metal of the electrical box otherwise the ground loop will return, then use 1" screws so that it will not go too deep in to not risk touching the inner layer of the electrical box otherwise the ground loop will return, plug in the DC to DC port of Camera again cover with black tape any exposed DC wiring you might have left, you dont want those touching any metal portions of the electrical box, install the cameras, repeat for all other cameras, now you have a perfectly isolated from that uncommon ground all cameras and you shall not get any ground loops anymore.

 

Additional info:

 

If you install the LCD monitor in a far away room or other location or even in an outlet connected to a different phase than the one where the DVR and Cameras are connected, you might get the ground loop syndrome again and those lines might return, resolution of this, connect the monitor to the same circuit where the DVR and all the cameras belong to. Ideally, you want to use CCTV Power Distribution Box (5 Amps for a 4 Camera install, 10 Amps for a 8 cameras install, 20 Amps for a 16 Cameras install, etc assuming each camera wont consume more than 1 Amps tops, and each terminal would be fused at 1 Amps and each terminal on the 20 Amps version is fused at 1.6 amps).

Thanks so much for your post, it's so helpful for me.

[00flash00 0]

Hi i have same problem maybe.

Cable is STP 4x2xAWG23, Category 6_A, 550 MHz, LSOH, Euroclass E_ca
I used videoBalun HD (is for tvi cameras) and in picture have color bar :/ But this is no problem for ground because ground problem is horizontal lines ... Picture is great and clear but only this color bar scrolling, only one scroling. Is hikvision 5Mpx cameras TVI ...
Distance is cca 120m

https://youtu.be/bMv5-bRfejI

[Sky66 0]

Hi just wondering if you did get any solution for this vertical colour lines in footage, as I’m having same issue at couple of installations and struggling to fix it out.

i have used cat5e pure copper and HD baluns and distance is less then 15m.

i will appreciate if you can share any solution thanks 

[Opeth 3]

Had the same problem.3 of 12 cameras has horizontal lines. But i change the format from pal to ntsc and seems that fixed the problem. I cant explain that