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I am doing a 200amp service upgrade and have to run 13 extension circuits to the old service box from the new panel. At one point the extension circuits will be near the phone wires (a mixture of CAT-5 and regular 2 pair station wire) and coax TV cable. They will be going through joists, so the joist holes will make all the cables bundled up and be close to the phone/coax.
My understanding is that I can cross coax at a 90 degree angle and not get interference from the extension circuits. True?? What about the phone cables? If I cross them at 90 degrees is that ok? Or what separation distance should I have? Will 6 inches be fine? How close can I run electric cables parallel to phone and coax? And if I do need to get close to these cables, is there a way to shield the phone and coax from interference?
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I am doing a 200amp service upgrade and have to run 13 extension circuits to the old service box from the new panel. At one point the extension circuits will be near the phone wires (a mixture of CAT-5 and regular 2 pair station wire) and coax TV cable. They will be going through joists, so the joist holes will make all the cables bundled up and be close to the phone/coax.
My understanding is that I can cross coax at a 90 degree angle and not get interference from the extension circuits. True?? What about the phone cables? If I cross them at 90 degrees is that ok? Or what separation distance should I have? Will 6 inches be fine? How close can I run electric cables parallel to phone and coax? And if I do need to get close to these cables, is there a way to shield the phone and coax from interference?
*Richard--It's O.K. for coax or phone wire to cross AC power at 90 degrees. As far as separation if they run parallel, my advice is--keep them as far apart as possible. The cat 5 and coax will be much more resistant to 60 Hz bleed over than the old JK station wire (2 pr, non-twisted red/green/yellow/black cable).In new construction, I try to keep UTP and coax at least a foot from AC wiring if they run parallel for more than a few feet. Other guys will run the phone and power wiring together (fewer holes to drill).If you want to shield the UTP and RG cables from the AC power influence, use a piece of EMT and ground it to bleed off the induced current.Unless you're going to run high speed data on the phone wire, keep as much separation is possible and don't worry about it. Unless you're miles from the telco central office, you won't notice any degredation in voice signal quality (signal to noise ratio will be lower if the signal is weak...)Good luck.
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For shielding information the two best sources of information are the FCC and the ARRL. Both publish RF shielding methods and criteria. If you have difficulty understanding some of their terminology ask the ARRL to refer you to one of their volunteer Tech Reps in your area.
Bless you for even thinking about this. In today's world of electronics everywhere and little shielding in commercial appliances and gear lots of problems could be avoided if everyone thought like you.
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Thanks, Fred, and Cap......I like to be forward thinking. I know interference can be a problem. I don't want an unhappy customer. I"m one of those that cares about that too, not just to make a buck and run :) Thanks very much. Now I can go to work tonight and know what to do :)
Rich
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Richard,
The spec sheets that come with the wire I use specify a 3' spacing (36") between parallel runs of data cable and your AC wiring. And, as others have offered, if they do meet, cross at a 90-degree angle.
Also, no tight bends or tight stapling with the CAT-5 if it is to be used for ethernet data networking.
*Instead of putting the data wires in EMT, you might consider BX cables -- built-in grounded shielding. The cat-5 (great for telephone) and RG-6 coax are pretty good at rejecting interferance already, but if run parallel to a powerful 60 Hz source (the AC) for a ways the current will transfer just like a transformer. Some say 1 foot, 2 feet, 3... but the length of the parallel run is really important too.The MUCH greater source of noise I found in a recent project was in the quality of the connections at punchdown blocks, etc. This is a pain to troubleshoot.
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I am doing a 200amp service upgrade and have to run 13 extension circuits to the old service box from the new panel. At one point the extension circuits will be near the phone wires (a mixture of CAT-5 and regular 2 pair station wire) and coax TV cable. They will be going through joists, so the joist holes will make all the cables bundled up and be close to the phone/coax.
My understanding is that I can cross coax at a 90 degree angle and not get interference from the extension circuits. True?? What about the phone cables? If I cross them at 90 degrees is that ok? Or what separation distance should I have? Will 6 inches be fine? How close can I run electric cables parallel to phone and coax? And if I do need to get close to these cables, is there a way to shield the phone and coax from interference?