EcoRenovator  

Go Back   EcoRenovator > Improvements > Renovations & New Construction
Advanced Search
 


Blog Register 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 02-12-17, 08:24 PM   #1
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,002
Thanks: 303
Thanked 712 Times in 532 Posts
Default Need advice about Cat 6 running parallel to unshielded Romex...

Anybody have any code or experiential advice about running Cat 6 Ethernet parallel to unshielded Romex?

The parallel run will be about 16 ft.

I've seen a lot of opinion but little code on such a thing.

In one UK post, citing code said to keep the runs separated by at least 2".

An opinion said they should each be metal shielded and no less than 12".

Quite a bit of variation there.

Thanks...

-AC

__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote
Old 02-12-17, 10:24 PM   #2
DEnd
Apprentice EcoRenovator
 
Join Date: Nov 2011
Location: NC
Posts: 117
Thanks: 6
Thanked 26 Times in 24 Posts
Default

Code is concerned with saftey, so there is a code issue with running Cat 6 parallel with Romex (as low voltage and high voltage cannot be run together, this is so that idiots who are messing in with wiring don't try to run 110v or 220v through low voltage wiring or equipment). Basically though they can run in the same wall but not through the same holes.

Best practice is to separate high voltage and Cat 6 by at least 12", use Electromagnetic shielded wiring, and limit parallel runs to less than 2'. That is not always possible though so if you need to get closer than 12" it should be a perpendicular run (at about a 90 angle) to the power line.
DEnd is offline   Reply With Quote
The Following User Says Thank You to DEnd For This Useful Post:
buffalobillpatrick (03-11-17)
Old 03-09-17, 01:00 PM   #3
TobyB
Lurking Renovator
 
Join Date: Sep 2016
Location: Carnation WA
Posts: 11
Thanks: 0
Thanked 2 Times in 2 Posts
Default

This is something we have some experience with at work-

from a safety standpoint, use different holes, as DEnd says.

From an induced current standpoint, your experience will vary depending
on a lot of factors, the first being how much current and how 'ugly' the AC load is.
If you're running a small alarm clock on the AC, the Cat5 will not care. If you're running
2 or 3 VFD's, it might be a problem.

The second big factor is how good the device using the Cat5 is. Good equipment
that makes proper use of the twisted pairs will be very immune to enough induced
current to cause problems. Equipment that does not take advantage of the noise
cancellation inherent in the wire will be a lot more susceptable.

So the real- world experience that we've had in temporary setups is that it's ALMOST
never a problem. Once in a blue moon we'll have to relocate a data line away from
a lighting dimmer feeder- but almost always, things that look ugly work fine.

Practically, in your shoes, I'd try to isolate the two as much as easily possible, and
not worry about it too much. If it's a typical home installation, you're just not
drawing enough current to cause problems. I WOULD use separate holes. I'm paranoid.

hope this helps,

t
TobyB is offline   Reply With Quote
The Following User Says Thank You to TobyB For This Useful Post:
buffalobillpatrick (03-11-17)
Old 03-09-17, 05:03 PM   #4
Ormston
Apprentice EcoRenovator
 
Join Date: Mar 2013
Location: UK
Posts: 131
Thanks: 13
Thanked 35 Times in 32 Posts
Default

UK regs (not that they apply) state 50mm, this is purely from a safety point of view and not interference.

The idea is that if the insulation on the Band 1 circuit (ethernet in your case) is not rated for Band 2 (mains voltage) then any damage to the mains cable could also bridge the undamaged Band 1 cables insulation and provide your router/pc with mains voltage.

From an interference point of view, ethernet is fairly tolerant. If possible 250-300mm should be adequate, failing that ftp (foil screened cable) grounded at 1 end or steel conduit again grounded at 1 end only will prevent any issues.

Also remember that to get the best possible throughput, the cat 6 should have no kinks or severe bends as it will be operating at rf frequencies and is more of a wave guide than a conductor.

Steve

Click image for larger version

Name:	IMG_20170309_213050.jpg
Views:	251
Size:	486.4 KB
ID:	7655

Click image for larger version

Name:	IMG_20170309_213120.jpg
Views:	237
Size:	454.8 KB
ID:	7656
Ormston is offline   Reply With Quote
The Following User Says Thank You to Ormston For This Useful Post:
buffalobillpatrick (03-11-17)
Old 03-09-17, 06:09 PM   #5
TobyB
Lurking Renovator
 
Join Date: Sep 2016
Location: Carnation WA
Posts: 11
Thanks: 0
Thanked 2 Times in 2 Posts
Default

That's a good idea to put it in conduit, if there's any worry.
It's certainly a very safe way to do it.

The thing about noise is that the twisting is 95% of the noise rejection,
at RF frequencies- any shielding or 'screening' is good for 5-9 dB, whereas
the twisting is in the 20-25 dB range. Which is REALLY counterintuitive,
but that's what the maths say, and our field experience really agrees with-
balanced twisted pairs very seldom have real RF noise issues, whereas unbalanced
signals are just antennas waiting to happen....

t
TobyB is offline   Reply With Quote
The Following User Says Thank You to TobyB For This Useful Post:
buffalobillpatrick (03-11-17)
Old 03-10-17, 05:42 PM   #6
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,002
Thanks: 303
Thanked 712 Times in 532 Posts
Default

Thanks or the replies!

You brought up issues that hadn't occurred to me.

Best,

-AC
__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 08:49 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design