RoyB

I am at a total loss here. My background is in commercial electrical but have installed 3 camera systems so far. My current issue is on a new install, 44 cameras. I have 3 power supplies (altronix sav18d) which are designed for CCTV, and 3 DVRs. Wiring is all cat 5, minus 2 outdoor cameras. We ran 2 cameras on 1 cat 5. Done it in the past without issues. 1 pair for power, 1 for video for each camera. The problem: horizontal lines. Solution 1: twisting 2 power pairs together for the cctv power supply. Solution 2: using a 12 volt computer monitor power supply on one pair I have not needed to do this before. All runs are less than 400 feet, some less than 200 and I have issues. I have tried EVERYTHING. Grounding is spot on, I've tried different power sources unhooking other cameras, etc etc. The only solution I have found that works is twisting two pairs together. That is fine, but building is complete and not easy to run 20 extra cables now. One thing I tried before twisting 2 pairs together was a different 12V source- I used a 12VDC video monitor power supply and tried it instead of the CCTV power and the picture works fine...with ONE PAIR for the power. How can I use 1 pair on that power supply, but a dedicated CCTV power supply I need to twist the pairs together? I would say it was a bad CCTV supply, but all 3 do it. I brought in an old power supply and had similar issues with wavy lines. Could the problem be the power supply in the end? The sav18D doesn't look like a real great unit, but is designed for this application. Would appreciate any insight. Thanks for the help.

This was spot on- It ended up being a ground-loop problem. I tested continuity on the cheaper cameras inside, and sure enough, Both - had continuity. The better outdoor cameras did not. We ran extra cables for parallel power to the 3 floors. The paralleling worked on floor 1 and 2. For some reason when we added extra power to the bad looking cameras on floor 3, the ones that looked good before now looked bad. WTF? I started unhooking the new twisted power cables that I ran. When I unhooked the Negatives on the power supply, the cameras were still on! Whoa. I was able to to unhook 4 Negative sides, leaving only the positives attached and I STILL had video on these things! Wowww. That really told me there was a ground loop issue. I had a hard time understanding it until I did this and saw first hand how much power was going back into the power side of the camera. Enough to give me picture! I hooked up one of the bad cameras to a separate power supply and it was crystal clear. It also makes sense when you check continuity how you could be getting "cross talk". The solution we are going to do for the last floor is put a couple plug-in single transformers in the ceiling for the 4 bad cameras. Hopefully that clears up the rest of the issues we have. This post was a real eye opener. I really appreciate the help and learned so much by troubleshooting this issue. From here on out I will make sure the boss gets better cameras, even if they cost an extra $20 to make sure they have a way to isolate video and power. Also I will never run 2 cameras off 1 cat5. We did it because that is what the boss wanted, even though we have done it in the past with success. I think he just learned that going cheap doesn't always work out well in the end. I suggested calling our supplier and asking why they would sell us cameras, dvrs, and power supplies that don't all work together. Appreciate the help. Just not sure why paralleling some of the cables on floors 1 and 2 fixed the problems and not the third floor. hmmmmm

how come when I unhook the other pair isolating it to just one pair for one camera power and video, the problem still exists though? Maybe I don't understand ground loop fully? Will running 2 pair of power for each camera help the situation? That is my next current step as I don't know what to do otherwise.

Problem persists with the following done: Blue=Video Cam 1 to DVR connected Orange=Video Cam 2 to DVR UNHOOKED at camera end Green= Power Cam 1 from CCTV power connected Brown=Power Cam 2 from CCTV power connected or unhooked I think the only solution is to run more cables. I just can't comprehend why it's fine with an external power source at camera end or head end.

A quick test whether it's voltage or a ground loop might be to leave the second camera connected to power, but disconnect its video feed. That would maintain the current draw (and subsequent voltage loss), while breaking the ground loop. If that eliminates the problem, then that's your answer. The best solution to a ground loop problem like this is to replace the cameras with cameras that have an internal regulator, which usually means 12VDC/4VAC dual-voltage cameras. The workarounds are a separate power supply for every camera, or ground-loop isolators. I will try this. So I understand correctly, you are saying to keep both cameras powered through the CCTV supply. Keep troubled camera plugged into DVR and unhook second camera on the cat 5 from camera end? ie: Blue=Video Cam 1 to DVR connected Orange=Video Cam 2 to DVR UNHOOKED at camera end Green= Power Cam 1 from CCTV power connected Brown=Power Cam 2 from CCTV power connected If problem goes away after unhooking video feed from second camera this tells me there is a ground loop issue and not voltage/power supply issue, correct? I am almost positive I unhooked the second camera from the DVR side, but not the camera side.

I am not sure I am understanding correctly. Are you saying to use a separate power supply for EACH camera? or just a separate pair to power each camera? It is currently setup for 1 power pair to each camera now. IE: Blue pair= Video Cam 1 Orange pair= Video Cam 2 Green pair= Power Cam 1 Brown pair= Power Cam 2 In troubleshooting this is what fixes a trouble camera Blue pair= Video Cam 1 Orange pair=unhooked Green pair=Power Cam 1 Brown pair=Power Cam 1 OR this works too Blue pair= Video Cam 1 Orange pair= Video Cam 2 Green pair= Power Cam 1 from single power source by itself Brown pair=Power Cam 2 from CCTV power source with 14 other cameras.

Yes, I have tried 2 pair for power, 1 pair for video for 1 camera and it corrects the problem (in my first post). Everything I read online says 1 pair is enough for power though? I don't have enough cable for 2 pairs to each camera though. Two cameras on one cat 5 are roughly 30-50 feet apart on average. I also don't understand how a single 12volt power supply with one pair for the power corrects the problem as well. If I needed 2 pairs for power it shouldn't (IMO) matter what the 12VDC source was, correct?

This is your problem - use only one pair for video, otherwise you don't get the noise rejection and balanced line function working properly. I am not sure if it was clear- but I am only using one pair (power/video) for each camera. There are two power/video pairs within 1 cat5 because I am powering 2 cameras. I am not using 2 pairs for one video feed which is what it looks like you are saying? One a side note, within testing, I have disconnected the second camera (on the cat5 line) from the power, dvr, and camera end completely and the problem persists. Basically eliminating any possible cross-talk/interference with the second camera.

Couple pics of the setup. Not sure why I never get a real closet

The power and video feeds were split at the head end/camera closet. Within one cat5e cable there are 2 power pairs being used and 2 video pairs being used. Roughly 16 cameras from each dvr/power supply. Power pairs are ran into the power supplies, and into the camera on the cam end. The video pairs have a Balun on camera side and DVR side. Baluns are models: (gem) BLN-TL and COMELIT-CNTB. It shouldn't matter if different baluns are used, correct? Grounding- All power is in conduit here. Originally I had everything bonded to the box/conduit system. Then I tried building steel. Last resort was running a ground wire back to the panel- no differences were seen in either. I am getting <.2 ohms from conduit ground to steel and <.1 ohms when I tested to building water supply nearby. IMO, grounds are solid and not the issue...especially with ground wire to panel run. I am pretty sure none of the runs are even at 400 feet. Most are <200 feet. Voltage at the camera UNDER LOAD is about 11.5 Volts. It drops 2 volts under load, without camera it is 13.5 volts. With the monitor power supply it drops 3 volts- 12 out, 9.5 under load and picture is clear. When I turn voltage down on the CCTV power supply to 12V out, the picture gets worse and turns off on a few. This to me makes zero sense. Cameras are capture, I believe these are the specs: SENSOR Image Device 1/3-inch SONY CCD Resolution 420 TV Lines Lens Fixed 3.6 mm Picture Elements NTSC: 510 (H) x 494 (V) PAL: 500 (H) x 582 (V) Minimum Illumination 0.1 Lux / F1.2 Video Output 1Vp-p (75 ohms, Composite) S/N Ratio 48dB (AGC off) Shutter Speed NTSC: 1/60 – 1/100,000 sec PAL: 1/50 – 1/100,000 sec White Balance Auto AGC Auto BLC Auto GENERAL Input Voltage 12 VDC – a plug-in regulated 750mA power supply is recommended (not included) Consumption 120mA Operating Temperature 14 to 122 °F; -10°C to 50°C RH 95% MAX (Non Condensing)

I should note, these are basic Dome cameras, not real fancy. Here is a video I took of the problem: http://www.youtube.com/watch?v=RMDYz78S1_0&feature=youtu.be