Running adjacent ethernet and mains cables?

[Lobster]

I'm currently installing the fixed wiring for our AV setup in the living room. I need to run mains cabling for the sockets as well as CAT5E cable for the Tivo box/smart TV; basically these both need to run to exactly the same location and the easiest solution would be to run them literally side by side, which in various places would be either under the floor, buried under capping below plaster, or in surface-mounted trunking.

I'm fairly sure there needs to be some space between them from a safety/regs point of view - right? how much? Is it OK if they cross over if not run actually in parallel to each other?

Separate to the regs issue, are there issues regarding interference to consider, too?

Thanks!

[spuorgelgoog]

Mains and ethernet should be run in separate trunking/enclosure or with a separating divider unless the ethernet cable is insulated to 240V.

Interference is unlikely to be an issue with Cat 5 and ethernet. It might be with Cat 6 (gigabit) ethernet, or with analogue audio/video.

Owain

[The Natural Philosopher]

+1.

In the absence of a physical insulation separator, there is IIRC a minimum DISTANCE, but the thrust of the regulations is to ensure that LV and HV cabling do not touch rub and chafe in the same conduit.

[John Rumm]

Crossing at right angles is less of a problem. Ideally keep them 50mm apart.

Unlikely to be a problem with ethernet, but may be one if using the same cables for analogue voice (i.e. phone) where you can pickup mains hum.

[Lobster]

On 30 Aug 2014, The Natural Philosopher grunted:

That's great; thanks all for the super-prompt response. I'll plan accordingly!

[cl]

50mm/2" is the figure I have in my mind for the required separation when there is no mechanical barrier.

[Tim Watts]

I would keep then notionally apart (not in the same trunking or pulled through the same (tight) holes.

However, if they do accidentally lay side by side somewhere or cross over or touch it is a complete non issue.

Look in any office false ceiling or under any computer room false floor to see how little it matters in the ordinary case (notwithstanding specialist sites like hospitals).

[The Natural Philosopher]

arbitrary, but pretty much correct I'd say.

[tony sayer]

Seen CAT 5 and 6 plus phone and co-ax and audio and mains cables all intertwined with each other and all working fine...

[The Natural Philosopher]

Oh it WORKS fine!

That was never the problem. The problem is a short so that you get 240V on your ethernet.

[ARW]

You get 230V now:-)

[Andrew Gabriel]

Ethernet has 4000V isolating transformers at each end of a segment to protect it from that!

[spuorgelgoog]

Possibly ones from ebay don't...

Owain

[jrwalliker]

...until somebody installs a lighting dimmer. I have a ceiling to light sw itch conduit containing lighting wiring and a phone cable (installed by a p revious house owner). No problems until dimmer switch was added. Then the interference on the phone became unacceptably loud. The wiring has now be en re-routed.

I have never seen problems with ethernet close to mains wiring.

John

[tony sayer]

And has anyone ever had that happen at all?..

Insulation on the mains cables insulation on the ethernet cables?..

[tony sayer]

And I doubt you will either its balanced line working which confers a very high level of immunity to interferer's..

[Capitol]

That's not a problem for long!

[The Natural Philosopher]

I am not so sure that it does mate.

Nope. No transformers anywhere.

[The Natural Philosopher]

I have never seen a network card WITH a transforner, and I must have sold tens of thousands in my time

[The Natural Philosopher]

Shows how good the regulations are dunnit?