Sign in with
Sign up | Sign in
Your question
Solved

Extra Shielding for Cat 6 Post Installation

Last response: in Networking
Share
January 12, 2014 9:35:12 AM

Hey all,

I have about 8x Cat 6 cables on a particular run exposed in my basement from one side of the house to the other.

Long story short, we just had some work done where the electrician ran 220V lines within 3 or 4 inches of the cables. I use these for some HDMI extender runs, so anything less than full bore on these lines becomes problematic.

No way I can redo the cat 6. For a multitude of reasons, getting the electrician to redo the work is near impossible and not a battle I want to get into unless there are no other options.

All of this is exposed, however, so I was wondering if I can add some extra shielding between the two runs to mitigate the damage: what do ya'll think about wrapping the cat6 in aluminum foil tape to reduce EMI? Placebo or actually useful?

If not some type of foil tape, is there anything else out there I could use? No 'you could use a new electrician' jokes, I already got that one from a friend.

Thanks in advance!

Best solution

a b X LAN
January 12, 2014 10:06:19 AM

Sure, aluminum foil wrapping the cables for about 18 inches to each side of the contact area will attenuate RFI -- 3M sells a tape product to do just that HERE. I would use the heavy duty foil and run it longitudinally so that there are no gaps in the area of interest. While more expensive and probably not necessary, the best EMI blocker is copper and 3M does make EMI blocking tape in copper, but it is more expensive and really won't do any better than a nice thick sheet of aluminum in most uses.
Share
January 12, 2014 10:17:29 AM

Well the obvious answer also (saving time and work) would be to go with a Wireless Solution instead. The new 802.11ac standard extends and strengthens the signal to allow more options with less equipment (repeaters) for most houses. Now if your have alot of cement / brick walls, yeah Cat 6 is the only option, but you might want to consider going wireless (your issue is one of MANY cited as the reason for 802.11x being a great simple cost effective solution).

Also consider, those wiring are subject to creatures, leaks, wear and tear; where as Wireless is not.
m
0
l
Related resources
January 12, 2014 11:11:21 AM

RealBeast,

Just the type of advice I needed, thanks! I saw that 3M copper stuff too and was hoping A) that either that or aluminum foil would do the trick (I didn't see the exact stuff you linked, that looks perfect) and B) that it would make a difference.

Tom,

I've got wireless all over the place - for my house I use the CAT6 for gig ethernet data (need that extra oomph and reduced latency compared to wireless for things like SAN) and direct runs (a.k.a. are not converted into data that is over a switched network) which carry HDMI signals, SPDIF signals, and USB extenders. The latter stuff is especially prone to EMI. Wireless for me is still used quite a bit but it's for non essential things like browsing from a laptop. Your points on expandability and cost are right and I would be only wireless if all of those other things were equal or not-terribly-important.
m
0
l
January 12, 2014 11:27:05 AM

I should add that this is 220V lines within 2 or 3 inches of my runs, parallel for about 80 feet! I may have made it sound like they were just a bit off on a perpendicular run before, but this was a pretty big oversight (again, long story, but if I were ever to give a free pass to someone, it's to the electrician that was under duress when he was working).

You think I still have a chance to reduce EMI if I string that aluminum foil for the 80 or so feet between the two parallel lines?
m
0
l
a b X LAN
January 12, 2014 11:44:11 AM

Fido_One said:
RealBeast,

Just the type of advice I needed, thanks! I saw that 3M copper stuff too and was hoping A) that either that or aluminum foil would do the trick (I didn't see the exact stuff you linked, that looks perfect) and B) that it would make a difference.

Tom,

I've got wireless all over the place - for my house I use the CAT6 for gig ethernet data (need that extra oomph and reduced latency compared to wireless for things like SAN) and direct runs (a.k.a. are not converted into data that is over a switched network) which carry HDMI signals, SPDIF signals, and USB extenders. The latter stuff is especially prone to EMI. Wireless for me is still used quite a bit but it's for non essential things like browsing from a laptop. Your points on expandability and cost are right and I would be only wireless if all of those other things were equal or not-terribly-important.


Fido_One said:
I should add that this is 220V lines within 2 or 3 inches of my runs, parallel for about 80 feet! I may have made it sound like they were just a bit off on a perpendicular run before, but this was a pretty big oversight (again, long story, but if I were ever to give a free pass to someone, it's to the electrician that was under duress when he was working).

You think I still have a chance to reduce EMI if I string that aluminum foil for the 80 or so feet between the two parallel lines?
Yes, and I would say that if you don't shield it over that distance you will have issues. Get a 100 foot roll of the heavy duty Reynolds foil (it will shield more and be less likely to tear when you place it) and be careful not to tear it or leave any gaps, especially on the side toward the 220 line -- but a complete wrap with no gaps is best by far since EMI is not just radiated in a straight line. You can wrap it multiple times, the better you "seal" the CAT6 lines the less potential for interference.

I guess that guy missed the day in electrician school where they said to cross data lines at right angles and to keep it running that way for 18 inches or more. :D 

If you wrap it well, I do not expect that you will have any issues, and certainly wired is far superior to wireless, even in this case.

m
0
l
January 13, 2014 5:25:41 PM

A question if you don't mind: Are you actually having problems? If so, what are they? Artifacts on the HDMI links?

I ask because I have never actually seen interference problems on Ethernet outside of a full-on industrial environment, but I've never transmitted HDMI over Cat 5/6 cable either.

Thank you.
m
0
l
!