Spacing between cables

[Neurorad]

I have some long LV cable runs to add in the attic, and I'm trying to decide how to group/bundle the cables. I'm concerned about 'interference'.

Should I keep speaker cables separated from other cables by 6-12 inches?

What about 4 conductor water sensor cables?

Ethernet cables contain twisted pairs to reduce 'interference'. How well is this accomplished?

What about an ethernet cable carrying POTS - should it be separated from other ethernet cables?

I think this long run is ~50 feet. Reducing the number of bundles will keep costs down, and make life easier.

I don't know of any standards.

This will also help me decide how to group cables in my basement <-> attic conduits.

Any thoughts would be much appreciated.

 

[AceCannon]

I have some long LV cable runs to add in the attic, and I'm trying to decide how to group/bundle the cables. I'm concerned about 'interference'.

Should I keep speaker cables separated from other cables by 6-12 inches?

What about 4 conductor water sensor cables?

Ethernet cables contain twisted pairs to reduce 'interference'. How well is this accomplished?

What about an ethernet cable carrying POTS - should it be separated from other ethernet cables?

I think this long run is ~50 feet. Reducing the number of bundles will keep costs down, and make life easier.

I don't know of any standards.

This will also help me decide how to group cables in my basement <-> attic conduits.

Any thoughts would be much appreciated.

It is my understanding that 120v (HV) and LV should be separated, and when they have to cross, it should be done at right angles if at all possible.

I do not think you need to separate LV runs regardless of type.

 

[Neurorad]

I have a feeling that DC won't be an issue, but AC would be.

From the Tip and Ring wiki:
"To ring the phone to alert to an incoming call, about 90 volts of 20 Hz AC current is superimposed over the DC voltage already present on the idle line."

Would 20 Hz be a concern?

 

[tmbrown97]

In my experience this has never been an issue with POTS. The only thing I might be concerned about would be the speaker runs, depending on the wire you're using. I'd probably use shielded wire to be completely safe. That said, I don't even thing it would matter with the amplified music - it's source runs that are more suceptible just because anything on them gets amplified, including any noise.

 

[KentDub]

I have some long LV cable runs to add in the attic, and I'm trying to decide how to group/bundle the cables. I'm concerned about 'interference'.

Keep everything at least 1ft (1.5 or 2ft ideal) from high voltage power lines, if you need to cross them try to do so at 90deg (form an X with it). Worse case is you have to run a close parallel to high voltage lines.

Should I keep speaker cables separated from other cables by 6-12 inches?

No, speaker cables will not cause any interference.

What about 4 conductor water sensor cables?

No interference.

Ethernet cables contain twisted pairs to reduce 'interference'. How well is this accomplished?

Extremely well. When terminating twisted pair cables try to keep the twisted as long as possible (i.e. don't leave a few inches untwisted before terminating to a keystone jack). That small amount can introduce slight noise, but only enough to be noticable on POTS. Check this out: http://en.wikipedia.org/wiki/Twisted_pair

What about an ethernet cable carrying POTS - should it be separated from other ethernet cables?

No, in fact, often times you will find POTS using a pair of wires in the same ethernet cable (limits your network to 100mbps if you do this though because you can't use all 4 pairs). Since you're running new wires, run a cat5 for network and a sperate cat5 for your POTS. No need to distance the cat5 cables from each other.

I think this long run is ~50 feet. Reducing the number of bundles will keep costs down, and make life easier.

50ft shouldn't be any issue. Just keep away from power cables if possible.

I don't know of any standards.

Neither do I.

This will also help me decide how to group cables in my basement <-> attic conduits.

Group physical location or logical organization. You do not need to be worried about interference unless you are close to high voltage lines.

In summary: High voltage is your enemy here, low voltage wires will not cause interference with each other. If you live in a location with abnormally high RF interference, your only protection is to use STP (shielded twisted pair).

Hope this helps,
Kent

 

[Neurorad]

Thanks for the recs.

I'll mull it over for a couple weeks, some other 'projects' need attention first - daughter's birthday, visitors, vacation.

 

[pete_c]

I "built" a run of cables from the basement to the attic. These are all LV wires. They do not cross over any HV wires. I can say now that they utilize a good percentage of the space between the studs on two floors. Its a real mix of a variety of different cabling. Cat5, RG6, 16/4, 18/2, 18/2, etc. I have two in wall speakers (2nd floor/1st floor hallways) adjacent to the runs and hear no hum/buzz on the speakers. I use the speaker openings to pass more cable if I need more. Wiring the second floor was easier using the attic down to each of the bedrooms. The cabling was done a little bit at a time and mostly each endeavor was for only one or two cables.