Water in old sat ribbon cable?

[trscott]

How much should I worry about 20-year-old sat ribbon cable that is buried in PVC conduit? I was thinking about trying to push an electrician's fishtape into the conduit a ways with some shoestring attached to see if there is water in the conduit.

Did I mention that it rains in Oregon?

One end of the conduit ends in a sealed PVC electrical box at the dish, and the other ends under a raised deck between some floor joists where it couldn't have gotten any direct rain, but the end of the conduit is not sealed.

The run is about 175', so I hate to change it out just for the heck of it, but if it would give me 3dB more signal, it would be tempting...

I guess the hot setup would be to get some video hard-line for the long run. Anybody ever try that?

 

[bryansr]

I put in a 4DTV a few years ago and the customer had a 12 foot BUD with RG59 in PVC Pipe. It had been in the ground for about 15+ years and sitting in water! It functioned OK with the OLD RECEIVER considering its age, BUT it wouldn't work with the NEW LNB & 4DTV receiver. Water wasn't the problem just the RG59. The OLD wire was seperate strands and the PVC pipe was too small for the ribbon cable. I just dug a new trench & placed the ribbon cable directly in the ground.

BryanSR

 

[nailzs]

Before I moved my dish I had the the coax, non ribbon, buried inside PVC for 20+ years and it worked until the day I moved the dish. I had the black coax seal on the ends of the PVC to keep out rain. I live in Florida were hurricanes dump rain by the foot, not counting the rainy season.

 

[WyrTwister]

How much should I worry about 20-year-old sat ribbon cable that is buried in PVC conduit? I was thinking about trying to push an electrician's fishtape into the conduit a ways with some shoestring attached to see if there is water in the conduit.

Did I mention that it rains in Oregon?

One end of the conduit ends in a sealed PVC electrical box at the dish, and the other ends under a raised deck between some floor joists where it couldn't have gotten any direct rain, but the end of the conduit is not sealed.

The run is about 175', so I hate to change it out just for the heck of it, but if it would give me 3dB more signal, it would be tempting...

I guess the hot setup would be to get some video hard-line for the long run. Anybody ever try that?

I have never found conduit in the ground , for any significant time , that did not have water in it . If it can " breath " , there will be condensate in the conduit .

Wyr

 

[truckracer]

conduit with water

Hey guys , when I installed my BUD about a year ago, I used sch40 pvc conduit because I "thought" it would be much better. And if i ever changed cables I can just use a fish tape to pull more wire if need be.

My conduit is full of water despite my best efforts to seal it. I paid careful attention to glueing the joints together and sealing the ends. My neighbor works for the local phone company and I was telling him about the water in my conduit.
He said that any conduit in the ground will eventually get water in it if it is not pressurized by air or nitrogen. He said this is what the phone company does to keep moisture out of their systems.

I may someday have to just direct bury my ribbon cable when i have problems and that may be soon.

 

[Mike500]

From all the years I've known, the telecommunications industry has never used glued together pvc conduit for running cable lines. They have always used flexible polyethylene pipe or tubing. PVC or vinyl jacketed cables in pvc conduit has over time "welded" itself to the walls of the inside of the conduit. Just a little bit of friction over a long length will prevent the cable from being pulled out.

Almost nothing "glues" to polyethylene. If someone were to invent a solvent to weld polyethylene, he would become rich overnight. On that note, you will always be able to pull cable through this stuff anytime in the future. As a master electrician, I've pulled many cables through conduit. There are little inside ridges in glued joints that cause fish tapes to hang, especially around curves. Since polyethylene does not bend to a small radius without kinking, it makes mild bends that allow for easy pulling. Even Belden recommends polyethylene, which is cheaply available at Lowes or Home Depot as water pipe.

For those who must have and insists on conduit, I use polyethylene. I've replaced the stuff, as the original poster inquired. Replacing the conduit is not that hard, depending on how deep it is buried. It is usually no more than 6 inches deep. I use a small garden tiller, like a Mantis to loosen the dirt above the conduit for 10-15 feet at a time. Then, I'd grab the end of the conduit and pull it right out of the ground. I'd then use a four inch trench shovel to scoop out the dirt, place the polyethylene, and refill the trench.

It's not as hard as you think.

 

[trscott]

No water...

Well, I am frankly surprised, but I secured a strip of terrycloth from an old towel to my electrician's fish tape and sent it more than twenty feet into my PVC conduit and it came out bone dry! (That got it well into the lowest elevation portion of the run.)

This is a run of conduit that I believe was installed sometime in the 80's by the guy that built our place. The conduit is grey PVC and as I said originally, it is open to the air on one end (but protected from direct rain under deck and overhang). I expected that condensation might have collected inside.

On the other hand, I didn't and still don't believe that buried PVC conduit will inevitably get water inside (although I am sure it is quite common). The secret to good PVC joints is to rough up both the mating surfaces with some sandpaper or emery cloth, then apply the glue to both surfaces, and "screw" the pieces together with continual twisting motion until the joint begins to get stiff, then hold it a few moments more until it becomes rigid. (In my younger days I actually was trained in this technique from one of the largest manufacturers of PVC pipe.) I guess the guy that put this run together must have done a good job of gluing the joints.

Oh, the full conduit run is about 100 feet and is probably buried three feet or more in good (frequently wet) Oregon top soil. (Yes I did say three feet, the guy liked his pipe runs real deep.)

Well, anyway, I guess the coax is probably okay. (Need to find a good way to adjust and confirm the dish focus setting next...)

 

[dfergie]

On the other hand, I didn't and still don't believe that buried PVC conduit will inevitably get water inside (although I am sure it is quite common). The secret to good PVC joints is to rough up both the mating surfaces with some sandpaper or emery cloth, then apply the glue to both surfaces, and "screw" the pieces together with continual twisting motion until the joint begins to get stiff, then hold it a few moments more until it becomes rigid. (In my younger days I actually was trained in this technique from one of the largest manufacturers of PVC pipe.)

My Dad was a Plumber, I used 2" Pvc water pipe to run mine...(80's)

Well, anyway, I guess the coax is probably okay. (Need to find a good way to adjust and confirm the dish focus setting next...)

check the FAQ's

 

[JerryK]

I wasn't "detail oriented" enough to bother with conduit when I put my system in last year. I just buried the cable--about 150ft.

But maybe after reading this it's BETTER that way. at least the ground drains water away, while conduit will hold any moisture it gets for years.

 

[trscott]

further comments, bottom drain...

Before I confirmed that my conduit has remained bone dry after fifteen or twenty years in Oregon, I was prepared to believe that there was no way to keep the water out, but now I would say that it may depend on how well you seal your conduit.

When I was assuming that I would probably find water in the conduit, I was thinking that a good plan might be to completely seal the ends, and then run a drain line from a TEE pointing down from the lowest point in the run, and then discharging into a some distance down into a gravel filled hole. Like a hatch in the bottom of a submarine, if the air can't get out, the water can't get in, and if the air seal ever failed, then the water could drain back out as the ground dried. On balance that ought to keep the cable drier than just burying it (well, unless you live in Arizona).

 

[gizzer777]

Direct burial

Before I confirmed that my conduit has remained bone dry after fifteen or twenty years in Oregon, I was prepared to believe that there was no way to keep the water out, but now I would say that it may depend on how well you seal your conduit.

When I was assuming that I would probably find water in the conduit, I was thinking that a good plan might be to completely seal the ends, and then run a drain line from a TEE pointing down from the lowest point in the run, and then discharging into a some distance down into a gravel filled hole. Like a hatch in the bottom of a submarine, if the air can't get out, the water can't get in, and if the air seal ever failed, then the water could drain back out as the ground dried. On balance that ought to keep the cable drier than just burying it (well, unless you live in Arizona).

I had made a post about using the drains, but it seems to have gone into cyberspace! <a good idea>

My 25 yr old direct burial cable has been dug up and moved to this house 12 yrs ago...never had a problem.

BTW: I am in Reno (desert like Ariz) but when it rains, it is monsoon time! (like right now). Also in the summer, my sprinkler system does a very good job of soaking the yard where the cable is buried.

As a side note. Here, the sun is so strong, it will eat and destroy normal sch 40 PVC over time (if exposed). My Ribbon cable gets sun full blast in summer where the cable comes out of the ground and into the crawlspace....even that part looks like new! Good stuff!
jeff