Data Line Buried w/Power

[Jim Becker]

Hunh? The phone company says DSL can go several miles. With even more bandwidth, the cable companies send wired signals a lot farther than 300 meters. I'm pretty sure that most cable is still copper; they make a biiig deal about it when they install fiber.

My apologies in not stating this specification is for Ethernet which is what the OP would be putting in his trench. Ethernet is limited to 100 meters on copper by specification and runs (currently) at up to Gigibit speeds on copper. It's a Local Area Network technology. (LAN)

DSL is an older technology for Wide Are Networking (WAN) and typically maxes out at about 7 Megabit speeds (only at very short distances) although there are some variants, such as what ATT uses for U-Verse between there community nodes and subscriber's homes, that might supply 25 mb+. It's not applicable in the context of the OP's situation.

[Brian Henderson]

I don't know since nothing I have is buried. Data comes in off of the phone pole and hits my shop first, then continues on to the house. Power comes off the pole as well, but it's separated by a couple of feet and I haven't seen any interference at all.

[Steve Milito]

Cat 5/6 Twisted pair has really good CMRR especially at 60Hz. The shielding has a nominal effect at low frequency and has magnitudes better effect at high frequency like RF (which can induce small phase differences between the pairs and lowers CMRR). A grounded shield can help eliminate ground loops if there is a issue with the ground planes and the way the two buildings are powered but to do that one would need to adhere to good instrumentation grounding principles. Otherwise, you're likely better not grounding the shield, which in essence makes it moot. Fiber is ideal for high speed point to point but last time I looked was relatively expensive to terminate on each end, but I may be wrong. Wireless point to point is also something worth considering and may be a good backup if a wired connection fails. My shop is 2000 ft from my house and the property is heavily wooded. I get acceptable data throughput with a 900 MHz data link. A 5Ghz radio would provide faster intranet than my internet link but the trees negated that choice.

[sean meltvedt]

Mark, to help us help you, could you give a little more information? What is the distance, and what kind of data? (Ethernet, analog voice, serial etc).
Most likely you will be fine with the conduit since you can always pull in a different cable-but if we had the specifics, you would have a workable solution from the start
Merry Christmas
Sean

[Curt Harms]

I'm no telecom pro like others here and my only experience is with phone wire and DSL. I ran a 4 wire untwisted wire fairly close to and parallel to romex, It didn't work. I rerouted the phone line away from and not parallel to any romex. It worked fine. I would think if the data cable is shielded and the shields are grounded you should be fine. If it were me, I'd put everything in place then power it all up to make sure there are no issues before backfilling.

[Mark Blatter]

Mark, to help us help you, could you give a little more information? What is the distance, and what kind of data? (Ethernet, analog voice, serial etc).
Most likely you will be fine with the conduit since you can always pull in a different cable-but if we had the specifics, you would have a workable solution from the start
Merry Christmas
Sean

Should have provided more info in my post. The distance is about 65 feet and yes it will be ethernet cable. After reading a bit more, I am thinking I will use direct bury cat6 cable. I will use wireless as a back up. The power will be whatever sized cable is required for the distance for 200 amp service. I am only running 100 amp as that is all I can with my present power meter without upgrading. City power does not permit a second meter at any address and I don't want to pay the $1400 to upgrade to a 450 amp meter, at least not yet. Down the road perhaps. I appreciate the help and suggestions.

[Jim Becker]

I think you'll be fine, Mark...just keep them separated as far as practical in your particular trench. Run multiple cables for the coms and consider throwing in a direct bury piece of coax, too, to give you all the options over time. It's cheaper to do that now than to add something later. You might consider getting a piece of pre-bundled cable for this...they generally include a couple coax, a couple Ethernet and sometimes a fiber or two, all wrapped up in one, easy to pull coil.

[John K Jordan]

I think you'll be fine, Mark...just keep them separated as far as practical in your particular trench. Run multiple cables for the coms and consider throwing in a direct bury piece of coax, too, to give you all the options over time. It's cheaper to do that now than to add something later. You might consider getting a piece of pre-bundled cable for this...they generally include a couple coax, a couple Ethernet and sometimes a fiber or two, all wrapped up in one, easy to pull coil.

Something I did in my 250' run to the shop was bury an extra 2" PVC conduit empty except for a rope.

JKJ

[Jim Becker]

Something I did in my 250' run to the shop was bury an extra 2" PVC conduit empty except for a rope.

JKJ

Yea, there's an empty conduit between the house and the shop here with a pull string in it. It originally had a 10-3 cable for a three-way switch and a power feeder in it for lighting and outlets to the building which was built as a garage by the previous owners, but that was pulled when I put in separate electrical service. I have it sealed on the house end right now because it's cracked some where in the middle (they foolishly used 4" SD instead of real conduit), but it's available if I needed to pull communications or a flexible water line out to the building.

[Mike Henderson]

Should have provided more info in my post. The distance is about 65 feet and yes it will be ethernet cable. After reading a bit more, I am thinking I will use direct bury cat6 cable. I will use wireless as a back up. The power will be whatever sized cable is required for the distance for 200 amp service. I am only running 100 amp as that is all I can with my present power meter without upgrading. City power does not permit a second meter at any address and I don't want to pay the $1400 to upgrade to a 450 amp meter, at least not yet. Down the road perhaps. I appreciate the help and suggestions.

I'm being a bit extreme here, but for 65 feet on copper twisted pair Ethernet, you can do just about anything, especially if you are running gigabit Ethernet or lower. Ethernet is pretty robust on short runs. Of course, take precautions but for short runs you shouldn't have any problems at all.

Jim gave some good advice on running multiple cables. You never know when you might cut through one by accident. Try to separate the two (or more) cables so that one cut doesn't get them all.

Mike

[Brice Rogers]

Mark, you wrote: " After reading a bit more, I am thinking I will use direct bury cat6 cable."

Some thoughts based on past experience:
1. I would suggest that you buy shielded cat6. That should just about eliminate any potential issues of interference from the power lines.
2. I would recommend using PVC conduit. Direct burial is quick, but I have had to repair direct burial that was chewed by a gopher or cut in two with a shovel or pick. For the few addition bucks that it would take to put in PVC conduit, I would recommend using a conduit. You don't want to be digging a new trench in 10 years or 20 years. The nice thing about conduit is that if you have a cable problem or later want to add another line (such as for an intercom, or security, or video surveillance, or Cable TV, etc.), you can do that without reopening your trench.
3. Conduits often accumulate moisture or even a bunch of water. Maybe that is because water condenses on cooler underground piping. I'd suggest plugging both ends with something (after the cables are in place) that could later be removed (like plasticine clay or spray foam , etc. Putting a cat 6 (shielded) cable rated for direct burial in a conduit makes sense as well, because if any moisture accumulates it won't matter. Standard cat 5 or 6 that lays in water (like in the bottom of a conduit) will absorb the water and cause the insulation to eventually fail. I've ohmed out wet cable and found high conductivity between adjacent pairs.
4. People who install conduits for the first time often undersize the conduit. Once they have tried to add an extra wire or cable they realize that the $5 or $10 they saved makes the pulling job a misery or impossible. Putting in a 2" conduit with 90 degree "sweeps" (gradual turn) makes the job really easy. I've seen people use 90 degree els intended for water - - that is, it has a real sharp bend. It is very hard to pull cable through those and you can sometimes damage the plastic outer sheath when pulling.
5. I've had great luck putting in a pull cord by using a shop vac at one end and wadding up a thin plastic grocery bag into a ball that is tied to a string. I've pulled some 200 foot runs with the shop vac and it took the wadded up ball about 3 seconds to go that distance. If I had "cheaped out" and put in a 3/4" conduit, it wouldn't have been so easy. With the 2" conduit you can even add a pull cord with a few wires down in the bottom. If you were running 1000 feet of conduit, then there would be a more serious cost consideration, but I think that you said that you only had 65' to run.

Good luck on your project.

[sean meltvedt]

Mark—Brice is spot on. That’s exactly what I would do at that distance.
Merry Christmas
Sean

[Steve Milito]

Coax is far more susceptible to 60Hz noise and should be kept as far away from the power line as reasonably possible. There is a major misconception in that shielding will protect the cable from 60Hz noise, that's really not true. Shielding benefit is inversely related to the wavelength of the field and proportional to thickness of the conductor. Having said that, there is no harm in running shielded Cat 6 cable other than the cost and mechanical properties of the cable. As Mike said, 65 ft is child's play for gigabit. One of my friends gets gigabit throughput on old Cat3 cable he pulled in the 80s.

[Tom M King]

In the 33 years that I built spec houses, and several times since, I ran multiple runs of black polyethylene pipe from the house to the road, or one building to the other, for pulling wires. Suck a mason's line, tied to a small rag, through the pipe with a vacuum. Any time you pull a wire, pull another line along with it. Black poly is cheap, and comes in long rolls. I never trench any kind of wire that's not in a run of it.

[Mark Blatter]

Thanks all for the advice. I tend to be cheap so have to fight that urge. I was planning on running an extra PVC pipe for future use, but was thinking of 1.5". I am sure that the 2" isn't much more.