Register
Log In
Home
Add Reply
Add Topic
June 16, 2014
Offline
Hi Guys
Ok, got my system, got the cameras installed, but I am fighting this horizontal scrolling line issue on one of the 6 cameras, the cable is not near any electrical wiring or electrical equipment and there are no florescent lights in the house, I believe that this is a ground loop, but man its kicking my ass.
I have tried different power supplies.
Single wall wart off of a different outlet.
Ground lift plug.
Ground lift isolator.
Also tried another RG59 shielded cable.
What else could be causing this issue on one camera out of the 6.
March 9, 2013
Offline
If you can, swap that camera with another working CVI camera of the same model. If the problem follows the camera then at least we know the issue is not in the cables or the power. If the problem does not follow the camera but stays on the same DVR channel, then we need to look at other possibilities. In that case, I would look at the power supply. Try to power the problem camera with it's own individual power supply. Also, if the power run is long try to power it locally.
June 16, 2014
Offline
Thanks for the reply.
Ok, I swapped out cameras from a known working camera and installed the camera with lines into the other camera location, the camera with lines in its new location does not have lines, the camera without lines in the camera location that had lines now exhibits lines, so I guess that means the issue is in the cabling.
The maximum length of the run with issues is approx 135ft, there is no where to power the camera locally..
I have tried powering the camera with its own wall wart and from the power distribution box.
Man, this is keeping me up at night LOL...
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.
March 9, 2013
Offline
135ft is a very long distance for 12V DC, even using 18 Gauge wire. Are you using 18 Gauge? Try putting the camera on its own unregulated power supply and use extra amperage. Try a 2amp 12V DC power supply or a 2000ma 12V DC power supply just for that camera.
May 4, 2013
Offline
Yeah, swap channels in the back and see if another line/camera does the same thing. That would point to that channel of the dvr being bad. Personally, I would take an extension cord out to the camera, power it up, and see if it clears up. Then you'd know if the camera was starved for power. That's like temporarily powering it up locally. 135' is a bit long, but not out of range I don't think. What wall wart spec did you try? I would go with 12v 2amp, as opposed to 12v 1 or 12v 1.5, which are more common but may not be enough to overcome voltage drop at that distance. You could even try 12v 4 or 5 amp too. It won't hurt anything as long as you make sure it's always 12v you're dealing with. But if possible, start at 12v 2amp and see, just because of the distance. If that's your longest run, of the others that have no problems, what's the distance of all those runs?
May 4, 2013
Offline
Also, 135' is not a common length of any premade cable. You don't have any extensions with two cables together in the mix do you? Don't do that. One single line out, always.
June 16, 2014
Offline
Tried all of the above, feel like packing this lot up and throwing it in the trash.
Things have got worse, lines have moved to all cameras, not just horizontal but vertical.
https://www.youtube.com/watch?.....e=youtu.be
Question, would Cat5 with baluns be better cable?
March 9, 2013
Offline
I hope you can agree that based on everything you have said there is no way the cameras themselves are causing the issue due to some defect. That does not look like a ground loop to me. That does look like a power issue though. Is your power box grounded properly? Also, do you have a voltage meter so that you can check the voltage and current at the end of the cable where the camera is connected. There is something there in that environment causing the issue.
Exactly what cable is being used here? Is it prefabricated cable or is it Siamese? What about the connections? Are you using twist on connections, crimps or compression? Look at the connections at the DVR, is there any exposed copper touching the connectors on the DVR itself?
Are the shorter runs having the same issue? As I said before, 12V DC at 135ft is really pushing it. If you check this voltage drop calculator: https://www.securitycameraking.....-drop.html and you are using a power box with 500ma per channel on 18 gauge 2 wire then at 135ft you are only pulling 11.136 volts. That is the bare minimum.
There is also an OSD in the camera. Have you accessed that? Make sure it is set to NTSC and 60hz not PAL and 50hz. Also, in the OSD, turn off auto sharpness. There are other settings in the OSD that can help. This issue you are having is somehow related to power or the cables. As Shockwave 199 recommended, you need to try powering the camera localy. Take one of the problem cameras down. Connect it at the DVR with a short cable and power it first using the same power supply with a very short cable. If the problem goes away, then the camera is not getting the voltage it needs at 135ft. If the problem is still there, then try to power it with a separate power supply using the same short cable. If the problem goes away with the separate power supply then the power supply you are using does not have enough power.
Some of the power supplies we sell auto adjust the amperage from 500ma up to 1.1amps. If you are using such a power supply then some of your cameras might be using more power than others. If you have a 10amp power box and 16 cameras for example, the first 8 cameras could be using most of the power not leaving enough for the remaining 8.
I know this is a lot of information, but sometimes the only way to solve these issues is through the process of elimination. If you don't feel you have the ability to trouble shoot, you can try a local electrician or we can refer one of our dealers to you in your area. We have around 1500 registered security dealers with our company so we will likely be able to find someone for you in your location.
June 16, 2014
Offline
I absolutely agree that the cameras are fine.
The power box is grounded its plugged into a GFCI outlet.
I am using an 15A 18 channel PDB, only using 5 of the power outlet channels.
The voltage on the longest run is 11.55v, the others cameras are getting around 11.86v.
Its pre-made Siamese, the BNC connectors were already installed: Solid Bare Copper, 128 wires 95% cover shield, foam polyethylene dielectric, CM/CL2 rated PVC jacket.
There are no stray copper wires anywhere.
Set to NTSC, sharpness is not turned on.
Tried powering the camera locally with an extension cable, still have the same issue.
The camera on a short cable to the DVR is great, no issues.
I found something out accidentally today, I had a piece of copper wire in my hand whilst holding the DVR, the other end of the copper wire touched one of the 2.1mm power supplies, two of the cameras displayed a great image with no distortion, so I guess this was like grounding through the DVR, which I know is not good, but why would that happen?
Could the DVR itself be bad?
Thank you for taking the time out to reply..
June 16, 2014
Offline
Also, I am going to run the cables again, would Cat6 be a better option?
March 9, 2013
Offline
IT's not impossible for the DVR to be defective, but the fact that the camera worked on a different cable tells me the problem could be the cable. Also, I have never seen pre-made copper Siamese. Siamese cable is sold in rolls of 500 or 1000 feet. I am suspicious of the cable.
I definitely would not recommend CAT6 or Siamese. Now you will be running power on 23 gauge cable instead of 18 gauge. Voltage drop will be more of an issue. I would purchase a roll of good quality Siamese cable and cut a new 135 foot piece, attach your connectors, lay it on the ground and test it with the camera. If this works, re-run the cable run with that.
June 16, 2014
Offline
Thanks Brad.
You guys have been really helpfull, I have purchased a 500ft roll all the BNC ends and am going to make my own cables.
Once again thanks for taking the time out to help..
FYI guys I have seen cameras do strange things when under powered. Even at 11.8DC. The DVR does have a grounding screw in one of the bags and the place to insert it is on back of DVR. The run wire from the screw to a ground in the room. Its possible the power supply is putting some feedback into the camera. Where are you taking voltage readings from? If you are getting those readings at the power supply that is not good. At the power supply should 12 or more volts maybe up to 13.4.
June 16, 2014
Offline
The readings are from the camera end, I have not measured at the power supply itself, but probably should.
I will check to see where the ground screw should go on the DVR, should that be taken to the main ground coming into the house, I can run a wire from the main ground to the location of the DVR.
Thanks again.
June 16, 2014
Offline
Got this issue sorted now, seems it was from a EMI interference, although the cable was really far away from the electrical wiring, I mean like 3.50 feet away.
We use really thick copper foil at work, I borrowed some of that and covered the wiring all the way back to the dvr, no more lines.
1 Guest(s)
