Cat5e vs. Siamese

[renz05725 0]

I have installed several surveillance systems the past couple of years and have always done so the way i was first shown : siamese cable (rg59), compression connectors and 1 main power distribution unit/power supply for the system.

 

I have recently run into a system that i am being asked to trouble shoot. They used Nighthawk bullet cameras with cat5e cameras, power baulins and it is being run to an video insight pc card. The majority of these cameras are about 300-350 feet from the mdf where it is being stored. The owner worked with 2 individuals on this project. He worked with a distributor who sold him the cameras, baulins, video insight card and cat5e. He then outsourced the labor to another company that had requested the cat5e cameras and baulins.

 

Well the company that installed has taken off and the cameras look like crap. I asked the distributor why they choose to use cat5e with baulins and he basically said that the installers wanted it that way because it was cheaper to buy the cat5e (obviously) than the siamese and they would make more money. My problem now is that i need to go check both ends of the baulins, check the cameras and the card (basic trouble shooting) and try to figure out why they look like crap. To top it off, they used the cheapest cat5e they could find on the market, which probably is not helping the situation.

 

my question is: why would you use cat5e over siamese other than cost savings? Am i missing something thinking that siamese is the way to go as long is the run is not longer than 750ft or ip?

[Soundy 1]

Well, Cat5 is generally more flexible/pliable and fits through smaller holes, so it can be less effort to install... plus you have the future option of adding more cameras (you can run up to four on a single piece of Cat5, power not included, or simply add another if you're using one pair for video and two for power), or you can install a PTZ in the future because you have a spare pair for control... and of course, there's always the future option of simply dropping in an IP camera if so desired (you can do it over coax using Highwires, but a pair of those will almost cost as much as the camera).

 

As to why it looks so bad... are these all 12VDC cameras?

[renz05725 0]

yes these are 12vdc cameras

[Soundy 1]

So let me guess, do the cameras all have wavy/shifting diagonal lines through the picture?

 

I've run into this many times with baluns on 12VDC cameras - it's a ground-loop problem caused by the fact that most cheap 12V cameras have a common ground internally between the power and video, and adding a balun to the equation just creates one ground path that's substantially longer than the other. It's not the fault of using baluns, or of Cat5 over RG59... it's the fault of cheap camera design.

 

There are a couple solutions... cleanest one is, if the cameras support 24VAC, to switch to a 24VAC power supply. That's probably not the case though.

 

I've had varied success playing with grounding the power supply and/or some (but not all) of the BNC sides of the DVR-end baluns, to the chassis of the DVR... either might help, or they might not, or they might make it worse, or they may just clear up some cameras and move the noise to others.

 

The only thing I've found that eliminates the problem, short of switching to 24VAC cameras, is to give each camera its own "wall-wart" transformer... or AT MOST, have two cameras per adapter. Naturally, that's not as "pretty", since it also generally requires two or three power bars (depending on the physical size of the wall-warts, the number of cameras, and the spacing of the outlets on the power bars). But I can pretty much guarantee it will clear up your video.

[renz05725 0]

is the best solution simply tearing out the cat5e and putting in saimese? I'm not talking about most cost effective, because obviously they went that route and it is killing them now. I'm talking about simply getting the cameras to work clearly, recabling with siamese would be the easiest soltuion and true solution, short of these cameras being crap? the cameras are Hawk-I HAWK-147IRCB.

[Soundy 1]

Tearing out the cable could be a lot more work than you're ready for. If it's just straight runs across open ceiling or something, that's one thing, but if it's running in and over HVAC, around corners, or if they've got it strapped up or hooked in T-bar hangers... you're potentially looking at a LOT of labor to re-run all the wiring.

 

I'm guessing this was a new construction when the system was put in, and now it's an operating business? If so, add to your rewiring labor, the fact that you either have to do it over and around their daily operations, or do it after hours...

 

Really, there's nothing wrong with baluns and Cat5 - it's inherently a slick setup that gives great results and offers a certain degree of "future-proofing". All you need to do is get around a power issue that stems back to the cheap cameras.

 

Easiest "fix" by far is just to replace the single power supply with a series of wall-warts. All the involved work takes place in a single location: the terminus of the Cat5 runs. Remove wall box, mount power bars as necessary, and splice existing camera power connections into transformers, one for each camera. The specs I found for the cameras calls for 310mA each, so if you can find a bulk-buy on 12VDC, 400-500mA adapters, you're laughing.

 

If possible, look for slim-profile types so you can cram more of them onto a power bar - like this one:

[renz05725 0]

this is in a warehouse and the cameras are up high in the open rafters of the building. there is not power where the cameras are located and i would need to run really long extension cords to them to supply power or have an electrician come and put some power next to them. They are about 20ft high (all of them).

 

from what you have read off the specifications of these cameras and know from the industry, are these lower end/cheap cameras?

[Soundy 1]

this is in a warehouse and the cameras are up high in the open rafters of the building. there is not power where the cameras are located and i would need to run really long extension cords to them to supply power or have an electrician come and put some power next to them. They are about 20ft high (all of them).

 

No, you don't need to put power AT the cameras - like I said before, just remove the current centralized power supply, mount power bars there instead, and connect the existing power runs that now terminate in the box, each to its own adapter.

 

from what you have read off the specifications of these cameras and know from the industry, are these lower end/cheap cameras?

 

I'm not familiar with that brand, but from looking at the various different listings for them, those particular cameras seem to be fairly mid-low-end. Most listings I found had them selling for $110-$140 (although a couple places were selling them for well over $200). Guess you don't always get what you pay for

 

Unfortunately, the common-ground design is pretty standard even with better 12VDC cameras - only the ones with built-in power regulators really get away from that problem, because the power ground is then separated from the video ground. 24VAC cameras avoid it because they necessarily need a transformer/rectifier/regulator to step the voltage down (since the internals in most cases still run at 12V).

[renz05725 0]

this is in a warehouse and the cameras are up high in the open rafters of the building. there is not power where the cameras are located and i would need to run really long extension cords to them to supply power or have an electrician come and put some power next to them. They are about 20ft high (all of them).

 

No, you don't need to put power AT the cameras - like I said before, just remove the current centralized power supply, mount power bars there instead, and connect the existing power runs that now terminate in the box, each to its own adapter.

 

from what you have read off the specifications of these cameras and know from the industry, are these lower end/cheap cameras?

 

I'm not familiar with that brand, but from looking at the various different listings for them, those particular cameras seem to be fairly mid-low-end. Most listings I found had them selling for $110-$140 (although a couple places were selling them for well over $200). Guess you don't always get what you pay for

 

Unfortunately, the common-ground design is pretty standard even with better 12VDC cameras - only the ones with built-in power regulators really get away from that problem, because the power ground is then separated from the video ground. 24VAC cameras avoid it because they necessarily need a transformer/rectifier/regulator to step the voltage down (since the internals in most cases still run at 12V).

 

where would i get these power bars from?

[Soundy 1]

where would i get these power bars from?

 

Almost anywhere... building supply store, electronic store, department store, surplus store, dollar store...

 

I'm talking about these things:

 

Use whichever style suits your needs and space requirements. The top one would work fine with the power supply style pictured further up.

[mitstarion 0]

In case will running a new set of wires to supply power (110VAC) to the wall warts near the cameras from the DVR end eliminate the diagonal lines interference?

[Soundy 1]

[NOWIN 0]

LOVE TO READ ABOUT PROBLEMS AND FIXES (SOUNDY, LOVE THE PIC, ITS WORTH A THOUSAND WORDS) LOL. HOW MANY CAMERAS? JUST WONDERING.

[mitstarion 0]

Sorry for the misunderstanding Soundy. Actually I got your point in using wall warts instead of a single central power supply box. I am just wondering if bringing the AC power and plugging the wall warts near the cameras instead of plugging the wall warts using power strips has the same effect?

[Soundy 1]

Sorry for the misunderstanding Soundy. Actually I got your point in using wall warts instead of a single central power supply box. I am just wondering if bringing the AC power and plugging the wall warts near the cameras instead of plugging the wall warts using power strips has the same effect?

 

Should have no effect at all on the noise problem. Only way it would make a difference is if the runs are too long and/or the wires are too small and you're suffering excessive voltage drop.

 

The noise in this case is most likely caused by a ground loop... if that is the case, simply eliminating the common connection will cure it.

[HeadsUp 0]

Soundy.......

 

 

just had to say ...............

 

 

great reply to his question.

 

 

your first reply answered it , but i echo you with the photo.

 

 

sigh.