CAT5E Cabling, Proximty to Electrical Cabling

Raistlin · 15-09-2007, 19:57

Anybody know if running Cat5e cabling near/next to 2.5mm electrical cabling (for sockets) or coax cabling (for, ummm, television) is likely to cause problems?

If so, anybody know what the minimum recommended distance/seperation is?

Thanks.

MovedGoalPosts · 15-09-2007, 20:01

I beleive it shouldn't run in the same conduit - mainly for risks of a dodgy connection or lack of sheathing somewhere creating risks of the Cat% becoming live. Same as telephony and other low voltage cabling really.

When my office was wired up a couple of years ago, surface mounted trunking was used with two trunking run parralel adjacent each other. One for mains and one for Cat5e and telephone. Thus you can run them close together, just not directly adjacent.

Halcyon · 15-09-2007, 20:10

Coax should be fine next to CAT5 but electrical wires should be apart.
Try to have them in seperate plastic pipes/conduits/ whatever they are called if possible to stop any interference.

Graham M · 15-09-2007, 21:03

We have Sky Coax, Phone Cables and Network Cables running in the same conduit at work in the office and it all works flawlessly. There is a chance mains cabling could interfere, but it is quite low especially over short runs, I'd be more worried about the safety aspect - just in case some poor wiring earthed onto some CAT5 or something along those lines.

Raistlin · 15-09-2007, 21:06

Not too worried about the quality of the wiring (muggins here is doing it), just didn't want the Sky/LAN signals degraded by radiation from the power cabling.

TBH I haven't got a great deal of choice in the runs, if I run the coax and cat5e under the floorboards they're going to be running near/over power cabling for lighting and socket circuits anyway.....

15-09-2007, 21:17

A magnetic field is present around mains cables which will induce problems with cable without the equivalent insulation properties, therefore a minimum distance of 300mm if running parallel with telecommunication type cabling, screened or not.

Personally I would run telecommunication type cabling in it's own zone if possible, just to be on the safe side.

Jon T · 15-09-2007, 21:22

IF you do any form of Network qualification(Cisco, CompTIA Network+ etc), you will get told that CAT 5 should be not be laid parallel with any other cable(power or signal) unless there is a certain minimum distance between them, I forget what this is. The main thing is that you don't run the CAT5 near things like low voltage tranformers or flourescent light fittings, these can generate wideband RF that is quite capable of interfering with ethernet.

Conventional wisdom is that CAT 5 and any other cable should cross each other at 90 degrees to avoid inductive coupling.

Can I just say though, taking all the above into account, the ethernet cable that feeds this computer runs alongside RG58 co-ax(which routinely carries RF from 3 to 400MHz at anything upto 100 Watts), and also a barrage of signal/power cables to the PC and my Radios, and i've never had any interference.

I would say you'd be fine, but I though i'd present both sides of the argument anyway.

Graham M · 15-09-2007, 22:13

Quote:

Originally Posted by Jon T

Can I just say though, taking all the above into account, the ethernet cable that feeds this computer runs alongside RG58 co-ax(which routinely carries RF from 3 to 400MHz at anything upto 100 Watts), and also a barrage of signal/power cables to the PC and my Radios, and i've never had any interference.

I would say you'd be fine, but I though i'd present both sides of the argument anyway.

With you 100% on that

xpod · 16-09-2007, 01:28

The only problem signals i ran into when wiring the relevant rooms for ethernet was the WAF.....the Wife Acceptance Factor

Raistlin · 16-09-2007, 10:47

Thanks guys, I'll take all of that into account.

I think I'm just going to have to apply the 'as much seperation as possible' theory and see how it goes

Cheers.

Dai · 16-09-2007, 12:34

Quote:

Originally Posted by xpod

The only problem signals i ran into when wiring the relevant rooms for ethernet was the WAF.....the Wife Acceptance Factor

I've found in the past that the WAF signal can be fairly well cancelled by application of a strong SST...

(shoe shopping trip)

xpod · 16-09-2007, 13:14

Quote:

I've found in the past that the WAF signal can be fairly well cancelled by application of a strong SST...

(shoe shopping trip)

Ahh,good ole SST...
I`ve been implementing SST for over 15 years now.........i`ve only had pc`s for one and a half of them of course

Reverse psychology is always good too mind you.
She thinks it was her idea to wire the place for internet