Steven Posted August 24, 2011 Share Posted August 24, 2011 In a previous year, I had a problem where some channels would turn on at random. I determined that the problem was likely caused by voltages induced in the LOR network cable from power cables that ran through the same conduit. The problem was solved by making a RS485 terminator.This year, there are again some places in my display where the network cable and the power cable run through the same conduit. I am thinking that using shielded twisted pair Cat6 cable instead of the regular unshielded cable when run through these conduits would solve the problem even without the terminators.Any thoughts? Link to comment Share on other sites More sharing options...
Jim Saul Posted August 24, 2011 Share Posted August 24, 2011 I use shielded uv direct burial cat 5E it runs with my main 8 power cords from the side of my house up to the front. Granted I've only got 1 year under my belt, but I didn’t have any issues, and that was about 60 amps going across the 8 cords with the cat 5 cable wire tied together for about 50 feet. Link to comment Share on other sites More sharing options...
KStatefan Posted August 24, 2011 Share Posted August 24, 2011 Why would you not continue to use the terminators? Link to comment Share on other sites More sharing options...
Steven Posted August 24, 2011 Author Share Posted August 24, 2011 KStatefan wrote: Why would you not continue to use the terminators?I will continue to use the terminators, but I would still like to reduce the noise on the network as much as possible. Link to comment Share on other sites More sharing options...
DownTown Posted August 25, 2011 Share Posted August 25, 2011 Steven wrote: In a previous year, I had a problem where some channels would turn on at random. I determined that the problem was likely caused by voltages induced in the LOR network cable from power cables that ran through the same conduit. The problem was solved by making a RS485 terminator.This year, there are again some places in my display where the network cable and the power cable run through the same conduit. I am thinking that using shielded twisted pair Cat6 cable instead of the regular unshielded cable when run through these conduits would solve the problem even without the terminators.Any thoughts?Hey Steven...I know that "shielded" cable sounds like a good idea. You think that if your conductors have that wrapper on it, you won't pick up interference from EMF sources. I spent a some time studying data communications and one of my hats is Data Communications Engineer. What I've learned about it, through study and practical application, is that unless the shielded cable is properly terminated to ground, the "shield" can act as an antenna, and actually increase the interference that you will experience.Aside from the performance question, there is a safety issue. I can't speak for the electric code in your neck of the woods, but here, low voltage (signalling) cable in the same conduit as high voltage is a no-no. It's not just unsafe, it's the law. You might want to rethink the way you install your cables, for safety's sake.D.T. Link to comment Share on other sites More sharing options...
Dave Batzdorf Posted August 25, 2011 Share Posted August 25, 2011 I do not use shielded anything and have no problems. I even have one 25' 2" PVC conduit run across my stream that has the data and power cord together. Again no issue. Link to comment Share on other sites More sharing options...
Steven Posted August 25, 2011 Author Share Posted August 25, 2011 DownTown wrote: unless the shielded cable is properly terminated to ground, the "shield" can act as an antenna, and actually increase the interference that you will experience.That's why I asked the question. It seems from your practical experience that shielded cable may not be the best choice. That's good to know.Aside from the performance question, there is a safety issue. I can't speak for the electric code in your neck of the woods, but here, low voltage (signalling) cable in the same conduit as high voltage is a no-no. It's not just unsafe, it's the law. You might want to rethink the way you install your cables, for safety's sakeI use the term "conduit" loosely. It's actually a 15' length of 3" ABS black pipe that runs under the lawn. The "high voltage" cable is an orange outdoor extension cord. I would assume the code would allow this temporarily, as most of us in this hobby run our cords this way.Here's another idea: How about running the Cat5 cable inside a 3/4" PVC pipe that is run inside the ABS "conduit"? This would keep it far enough away from the power cord to avoid picking up interference. Link to comment Share on other sites More sharing options...
Max-Paul Posted August 25, 2011 Share Posted August 25, 2011 I agree with Downtown. NEC does not really allow low voltage and high voltage in the same conduit for any purpose that I know of. And the breakover between low and high voltage I believe is 50 volts.Sounds like D.T. has more practical experience than I. But will share this from what I have been trained. Take the drain wire that runs with foil to a good hard earth ground as near to the point that the drain wire exits the cable. Do Not ground both ends to a hard ground. You can do a soft ground via a .01 disk capacitor. Link to comment Share on other sites More sharing options...
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