Video Signal Cable Next to Electrical

[eqkimball]

I'm a mechanical guy so this may sound silly.

I have in-floor outlet boxes in my house, which is under construction.

I would like to add a video cable (such as a PC monitor cable) through the conduit with the 120v wire. The side-by-side run will be approximately 8 ft. The slab is poured, so I'm stuck with a single 1" conduit.

Could the power wire cause interference with the video?

Is there a commercially available cable that would eliminate all or most interference?

Am I wasting time and money by even attempting this?

Any advice is appreciated.

 

[itsmoked]

If you are truly talking about the monitor cable you will have a problem. Those signals can not go very far. Have you ever seen a monitor cable longer than about 5 feet? They can only go about 12ft max.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[MacGyverS2000]

Could it cause interference? Yes. Will it? Depends. For something like a computer monitor, I would look into one of those converters that transmit a few hundred feet over Cat-5 cable. That may be overkill for the distance you need, but I'm with Keith... even with magnetics at the cable ends, you're going to see some nasty color effects and blurring if you use a standard cable, particularly at the higher resolutions today's monitors support.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[VEBill]

It's very common for projectors hanging from the ceilings of meeting rooms to be wired to the meeting room's PC's 2nd VGA output. One factor that helps the VGA signal span the 20 to 30 foot gap is that the older projectors were typically very low resolution (800 x 600) and the 2nd VGA output was set accordingly. I'm positive that we have several such long VGA cable installations at my workplace.

Another consideration is that the AC wires are probably headed to the same display device as the video signal. As opposed to an arc welder. So the AC wires are probably not carrying a great deal of noisy variable current.

I'd say that if you can obtain well-shielded cable for the video signal, which will obviously require field termination, and can try it without spending a fortune and without too much effort, then it might be worth a try. But if it becomes a big deal to try video cable, then skip it and try the Cat 5 adapters or something similar. And use well shielded wire there too.

 

[DanEE]

Not a problem when properly done to avoid ground loops..

e.g.
I have a high end stereo system and a large screen HDTV system that takes 50' of cable to run between the two systems..

There is also a 50' VGA cable connecting a laptop PC to the HDTV video and audio in.. The laptop and HDTV are on the same UPS powered branch circuit. That installation has been problem free.

In your case it would be best if the monitor and the computer powered at the respective ends of the conduit run to center floor connection is on the same branch circuit to minimize any ground loop currents.

Unbalanced (consumer RCA type) audio connections can be more problematic especially in the cases that dictate connecting equipment fed by different branch circuits. But there are ways to minimize that problem.

Commercial theatre/auditoriums sometimes feed all audio equipment throughout the building from a single appropriately sized distribution panel with isolated ground system e.g. same codes as required certain hospital areas. An of course, theatre/auditorium low level signals are on balanced audio connections which is far better.

 

[DanEE]

One thing I forgot to suggest that may be the easiest solution of all..

If you are buying a new PC monitor and computer, you might consider getting them with a HDMI video interface.. This will put you in the higher end, but not that expensive, of monitors and video cards. They are readily available today.

You should be able to get an assembled HDMI cable through 1" conduit if it is the first cable through..

HDMI is designed to work up to 15 meters or 50 feet without the need of a repeater.

DVI interfaces are also available, but a DVI (on both ends) will not fit through a 1" conduit. Drive distance is more limited, but should be OK for your 8 feet. You could use some combination of DVI to HDMI as HDMI was designed to be backwards compatible with DVI. VGA at some point in the not too distant future be an obsolete standard.

for more info, you might do some reading here on DVI, HDMI and if you do go VGA, the differences in the construction of VGA and SVGA cables..

https://www.cablewholesale.com/index.php?section=Support&body=Technical Articles

also best source I have found for reasonably price, high quality cables.