Using UTP for power and video

[tlavite 0]

Okay so I know they make baluns for this exact purpose. But I want to know your guys opinions on this.

 

What would be so wrong with running the video signal like this:

Positive Video = W/Blue

Negative Video = Blue

 

And sending the 12V like this:

Positive 12V = W/Orange, W/Green, W/Brown (Twisted Together)

Negative 12V = Orange, Green, Brown (Twisted Together)

 

Of course the color choice does not matter. Just a thought figured I would see what you guys thought about it.

 

(Edit) I forgot to mention that I would still include a regular balun on the video line. It just would not be a POE balun.

Edited June 3, 2011 by Guest

[dustmop 0]

What kind of distance are you talking about?

 

(also, I think Blue/White should be positive, and Blue negative, but that's just how I do it)

[Numb-nuts 1]

I am not sure if it would give you a reliable picture or if it has any detrimental effects, but what have you got against poor old passive baluns? I believe the idea of baluns, is to correct the impedance of the line or was it signal?

 

I am sure someone will tell us.

[tlavite 0]

I am not sure if it would give you a reliable picture or if it has any detrimental effects, but what have you got against poor old passive baluns? I believe the idea of baluns, is to correct the impedance of the line or was it signal?

 

I am sure someone will tell us.

 

 

Actually I did forget to mention that I would still include a regular video Balun on the video line but was just wondering if it would be okay to actually twist them 3 wires together and send power down the same cable without using a POE balun. And as far as distance goes, anywhere from 200-300 feet. I am just thinking if this is not in anyway terribly bad it would save some money by not having to buy POE baluns and buying and crimping ethernet ends on my lines.

[tlavite 0]

What kind of distance are you talking about?

 

(also, I think Blue/White should be positive, and Blue negative, but that's just how I do it)

 

 

You are right about the color I agree I just typed it wrong and for distance about 200-300 feet.

[thewireguys 3]

You could also use something like this to keep everything clean.

 

 

http://www.muxlab.com/products/ve_cctv_power_thru_balun.htm

[tlavite 0]

You could also use something like this to keep everything clean.

 

 

http://www.muxlab.com/products/ve_cctv_power_thru_balun.htm

 

Thats actually what we used at one job. My boss had just asked me this mourning about running the power and video down UTP without buying a balun like that because they cost more then a regular balun. I agree and think its allot cleaner to use the balun you linked to. I was just looking for some input to relay to him about it. In my opinion for a short distance it wouldn't be bad but for long distances it might be a better idea to just buy the poe balun.

[Soundy 1]

Nothing wrong with doing it this way - we've almost completely stopped using coax for new installations, using basic video-only baluns. Personally, I use blue for video + and blue/white for video -, then use orange pair for power "hot"/+ and green pair for power "neutral"/-, leaving the brown pair as a spare.

 

Also, those "POE baluns" are doing exactly what you're proposing to do with the wires - all they are doing is connecting the power wires to six of the eight wires. They are NOT PoE - there's no "ethernet" involved, and PoE spec is a lot more involved than just putting power on some of the wires (look up "802.3af").

 

Frankly, there's no reason to use any particular pair of wires for video or power or anything else - I chose blue just because it's the "center" pair and would thus make the the layout compatible with most types of RJ jacks and wires - in a pinch, I could even use a standard two-wire RJ11 phone cord. In some installations, I've used the "spare" brown pair for a second video run... in some, for RS-485 control signal.

[Soundy 1]

In my opinion for a short distance it wouldn't be bad but for long distances it might be a better idea to just buy the poe balun.

There is NO difference between using this or a separate video-only balun and connecting power to the other pairs directly, other than it being "cleaner" (and in my experience, it's really not... and frankly, not substantially more convenient either).

[tlavite 0]

Nothing wrong with doing it this way - we've almost completely stopped using coax for new installations, using basic video-only baluns. Personally, I use blue for video + and blue/white for video -, then use orange pair for power "hot"/+ and green pair for power "neutral"/-, leaving the brown pair as a spare.

 

Also, those "POE baluns" are doing exactly what you're proposing to do with the wires - all they are doing is connecting the power wires to six of the eight wires. They are NOT PoE - there's no "ethernet" involved, and PoE spec is a lot more involved than just putting power on some of the wires (look up "802.3af").

 

Frankly, there's no reason to use any particular pair of wires for video or power or anything else - I chose blue just because it's the "center" pair and would thus make the the layout compatible with most types of RJ jacks and wires - in a pinch, I could even use a standard two-wire RJ11 phone cord. In some installations, I've used the "spare" brown pair for a second video run... in some, for RS-485 control signal.

 

 

Awesome thank you! that is exactly what I was thinking!

[Numb-nuts 1]

I would concur that using a combined balun for power and video is worthwhile. At most you might save a few ponds by just using a video balun, but you could end up spending the money in time taken over fault finding if you go the other route.

 

But to answer your question directly there is nothing to stop you just twisting the remaining three pairs into two pairs for power =ve and -ve. I would say that if you do this decide on a wiring colour convention and stick to it rigidly.

When you twist the pairs together, terminate them with a bootlace ferrule before fitting to a screw terminal, you will get a better connection, but you will need a pair of ferrule crimpers (from about $10 - $50 typically)

[Birdman Adam 0]

It is totally worthwhile, and saves money as well. I used one pair for video, two pairs doubled up for power (12VDC), and the fourth pair as a tamper loop going to the alarm system. When the load are under like 1-2A, your good to go with voltage drop.

[dustmop 0]

You are right about the color I agree I just typed it wrong and for distance about 200-300 feet.

 

 

At that distance, there's nothing wrong with the way you want to do it, so long as the cameras are not outdoor models with heaters. If you ever need to go farther, or outside, I would recommend a dedicated 14/2 or 16/2 for power.

[Numb-nuts 1]

At IFSEC this year I picked up a couple of sample baluns that have video, power and RS485 over a single Cat5 cable.

They claim to be good for 12vDC and 24AC up to 300 m. I am not sure how reliable they would be but if I get an opportunity to try them I may do.

 

Simply plug and go. Doubtful.

[tesc_cctvpro 0]

Interesting - my experience has been that we don't ever use single inline baluns, and probably will never send power over UTP again.

 

We rather use a setup where we have distribution blocks of 4 or 8 channel baluns and co-axial drops from the balun to camera. Inline baluns are a nightmare during fault finding and repairs - especially if height or access is a problem. I think RJ45 connectors on balun may be a bit more desirable than the cheap screw type of clip on connectors .

 

The power drop over UTP is astounding , and having to use duplicate pairs, kind of detracts from the appeal of UTP.

 

Thats just the way we do it though, and maybe time have changed ---- maybe the baluns are not so finicky any more?

[Soundy 1]

Why is that doubtful? One pair video, two for power, one for serial? Granted, you won't be able to provide the power needs of most PTZs at that range, but in itself, the claim is valid.

 

Now if they're claiming to do it with, say, a Spectra IV at that distance, I'd be really skeptical - with heater/blower going, I believe these things are rated at over 75VA, and even 16/2 at 28V at the supply would be sketchy at 100m, nevermind using ALL the pairs of a single Cat5e.

[Soundy 1]

I think RJ45 connectors on balun may be a bit more desirable than the cheap screw type of clip on connectors .

Ugh, no thanks - seen too many with bent pins, and on the whole, it's proven to be far more of a hassle.

 

We've been using these gems (pun intended): http://bit.ly/jzxBih

 

These fit wonderfully inside the back-box of a CNB VCM-series dome, along with the power connectors. Haven't had a problem with one yet, even in outdoor installations.

 

The power drop over UTP is astounding , and having to use duplicate pairs, kind of detracts from the appeal of UTP.

It's not all THAT bad, especially using 24VAC. Pair with a good dual-voltage camera that will accept DC or AC input between 10 and 30V, and there should never be an issue.

 

We've just been using the blue pair for video, orange pair together for power "hot", green pair for "neutral", and brown left as a spare... working great on dozens of cameras.

 

Thats just the way we do it though, and maybe time have changed ---- maybe the baluns are not so finicky any more?

I did some quick-and-dirty testing a while back, comparing a variety of GEM, MuxLab, NVT, and GVi baluns on my bench, recording a CNB camera to a Vigil DVR over about 800' of Cat5e, still coiled inside its box... I found practically no noticeable difference between any of them, from the cheapest $8/pair GEMs to the most expensive $45/each NVTs, and no visible difference vs. the 20' RG59 run on my test bench either.

 

This is a great little calculator, BTW: http://www.netkrom.com/voltage_loss_over_cat5_calculator.html - even at a full 1A draw (most non-IR cameras are a fraction of that), you see less than 4V drop using 24V over two pairs. The CNB cams we use are under 300mA normally, which equals a loss of barely 1V.

[Numb-nuts 1]

Well I am willing to try anything once, or I'd never learn anything but it will have to be on my own equipment.

I think I'll experiment a bit on my own PTZ camera when it comes back from the manufacturer, AGAIN.

 

 

I use bootlace ferrules in any connection that have screw-down terminals, no more intermittent connections etc. In most cases I have to trim the ferrule a bit to make it go fully home but it's never a problem. A bootlace ferrule plier can be bought for as little as $10 on ebay and a ratcheting one from about $25.

0.25 mm (violet) ferrule can terminate one UTP conductor (double it over)

0.3 mm (pink or Turquoise) ferrule I have never used so can't tell

0.5 mmferrule(White or Orange) can crimp onto two or three UTP conductors if carefully stripped and twisted

[tesc_cctvpro 0]

Yep, often times we also reverted to 24V when power over UTP was concerned. Sometimes just pure 24V cams and others using 24V/12V step down!

 

Nice tip there numb-nutz! Thanks...

[3RDIGLBL 0]

We do exactly what soundy is describing here and we use the same baluns. In reference to the outdoor cameras.....we have an install running over two years now at about 150' distance using Arecont 3130's inside an enclosure and power running over the UTP without any issue what so ever. We told the customer what we were going to try and if any issues come from it we will address it and to this day every thing has been great. The Arecont's were 12v so we used a step down and to my surprise none of those have failed either.

 

Since it can drop to -40 in winter evenings up here I am really impressed with it. Everyone has there opinions but the best way I find is to just do it and see how it turns out knowing that it just might not work. Trying it will at least provide you with some experience and knowledge in a real life situation.

[tlavite 0]

Wow I'm so glad everyone responded to this! Thanks everyone.

[jeromephone 6]

We are old school I guess We will run cat6 for runs of 300 feet or less. That way if customer swithches to IP cameras they are all set. I still like to run a seperate power wire probably not necessary but I like to keep spare pairs on the cat 6. With a 16/2 and extra pairs on the cat 6 adding another camera should entail minimual wiring

[3RDIGLBL 0]

Cat 6 adds cost to the hardware. Cat 6 is not needed for any ip camera on the market. We will run cat 6 for switch uplinks because of the bandwidth requirments to push multiple cameras but for a single camera we don't.

 

A box of cat 6 is almost double that of cat 5e and in some instances I found that it is double.

[Soundy 1]

^Agreed - Cat5e is rated for gigabit as it is. Unless you're planning 10GbE or higher expansion in the near future, there's little call for the extra cost.

[thewireguys 3]

FYI if you plan on using 10GB networks you need Cat6A. Cat6 will only work for distances.