Running 24V AC 7500ft

[doyo 0]

Hi, all.

 

I need to run 7500 ft of cable to power up a couple of active baluns and a camera inside a tunnel. According to various calculators I found online I should use 10 gauge 2 conductor cable with about 32V power supply to deliver 1 amp in 24V AC. Does that sound right?

 

I have not been experienced with such long power cable run, and I am not sure if this is the right direction. Please advise.

 

Thank you.

[ssnapier 0]

The power is not the problem, what is your plan to get the video signal to travel that distance?

[doyo 0]

The power is not the problem, what is your plan to get the video signal to travel that distance?

 

I am using 2 sets of NVT active units for video.

 

The power is not a problem? Awesome! How would you take care of the power?

 

Thank you.

 

Also if you have an idea on video part as well, please share.

[qrcctv 0]

I would not recommend to carry 24V for such a long distance.

 

Stick to 240V or (110V depending on where you live) and convert nearer to the cameras.

 

Even for this mains voltage you need to use a expensive thick cable.

[ssnapier 0]

I meant that your calculations on the power sound correct, so that part is handled. Which NVT units are you using for this and have you considered using fiber optics?

[doyo 0]

I see.

 

These are the NVT units I plan to use:

 

http://www.nvt.com/content.php?type=product&key=652r&cid=root

http://www.nvt.com/content.php?type=product&key=653t&cid=root

 

They suggested that I use two sets of these to cover up to 8000 ft.

 

Yes, I considered fiber, too. But because of higher cost involved with it we decided not to.

 

Thank you.

[ssnapier 0]

So those are limited to a mile (5280 feet) which leaves you 2220 feet short of your target distance. Those cannot be daisy chained, so unless I am missing something it seems to me that fiber is really the only reliable option.

 

If this is for a single camera, you might be able to use a 900Mhz wireless system but you still need power on both ends for that unless there is a solar option with battery backup.

 

Also, are you aware that you have to use LS-ZH cable for anything being run inside a tunnel? If I had to guess, I would say cable costs alone for just the power are easily going to be $40,000 without any other equipment or a minute of labor figured in.

[doyo 0]

NVT told me that they can be daisy-chained to cover the distance. So I will have to give it a try. Plus my customer did not want to go fiber because of the cost.

 

Solar power could not be obtained. That was the first thing I looked. It would have made it so simple.

 

Use of LSZH cable has never been specified. I will look into that. Thank you so much.

[jeromephone 6]

Maybe could probably have a small electrical service installed meter etc for what all the cable and special connections are going to cost, then you would have no power problems and could go to wireless etc.

[ssnapier 0]

NVT told me that they can be daisy-chained to cover the distance. So I will have to give it a try. Plus my customer did not want to go fiber because of the cost.

 

Solar power could not be obtained. That was the first thing I looked. It would have made it so simple.

 

Use of LSZH cable has never been specified. I will look into that. Thank you so much.

 

LSZH is only a requirement if there will be people in that tunnel, it is a fire hazard and a very serious threat to human life to use standard or even plenum cable in a tunnel.

 

As for the daisy chain, I would make them draw you a diagram of exactly how that is supposed to work because that make no sense to me at all! If they do give you a drawing, I would love to see it!