How to keep power and data cables apart?

In article , Piers Finlayson scribeth thus

Well regs is regs .. but I know of several places where mains are wrapped around CAT 5 cables in ducts cable trays everywhere and they never have any interference problems!...

I'm not sure its got anything to do with interference. A plastic insulator is permitted and that has (almost) zero effect on interference. You wont do any damage to Ethernet kit even if you connect the cat5 to mains, they have 1500V isolating transformers on each line. However the RJ45 plug offers no protection other than a few bumps of plastic so the shock potential is high.

The regs are concerned about mains ending up where it would not be expected like the end of a network cable. The insulation on network cables is not mains rated.

As to the OP's problem:

Run the mains in a bit of conduit behind the box. Run the mains through a bit of conduit in the box. If the conduit extends outside the box all the better. Cut a bit of suitable thick plastic the size of the box, run the mains through shove in bit of plastic, fit data cable "safe" side of plastic.

Think I'd go for a bit of oval conduit longer than the box and fit it inside. Probably modifying the box so the conduit can go in flush against the back. I'd also write on the conduit what it contains.

Add an old-school light dimmer with no filtering and try that...

Thanks for the suggestions.

It probably wont have any effect. It would induce common mode noise and Ethernet is good at rejecting that sort of noise. It has to be good at it as it picks up lots of common mode noise from everywhere not just dimmers.

SystemX uses STP BTW, however the screens aren't there to stop noise being picked up on the cat5, they are used to lower the emissions.

System X? The final death knell for wire wrap, as the backplanes and their porcupine forest of radiators did their best impression of an Aegis radar array.

Oh, so you're younger than I thought.

System X started out as wire wrap. Worked great on the bench, but when you hinged the frames back into the rack, adjacent frames wanted to chat with their neighbours and didn't want to do much else. One of the things that showed up on thre first exchanges, like Hale. Supposedly Woodbridge was always so full of Martelspods poking at it that they never got round to closing the doors anyway.

The question is distance. UTP is good at common-mode rejection for noise sources that are "distant" compared to the pair spacing. Run parallel cables in close proximity though and it's a whole new problem.

I don't know which bit you are talking about but the processor didn't have any hinged swinging bits even when it was in the PPU/POPUS stages and was wire wrapped. Maybe you are thinking of the 2BL days?

That's why there was going to be a man and a dog to man the exchanges.

The Martelspods were nothing compared to the Chinese delegation we had 4 years ago, they actually started unplugging the cables and cards while we were demonstrating what the kit could do!

Running it so it was close at intervals would be worst, each pair is twisted so each leg takes it in turn being closer to the mains wire, the effect should be to reduce the noise even at close spacing. Obviously kinking the mains/Ethernet cable at exactly the right intervals could make the noise worse, something to remember if you want to sabotage an installation for some reason.

Hardly likely to be up against bare HV conductors.. but regs is regs...

Bin there dun that with fairly high power RF fields too.

Balanced operation sure can cope with a lot:)...

I had an idea that both CAT5 type and CW1308 cables, although they're rated at something like 80V, are allegedly "insulated" to 250V.

ICBWT.

In article , Frank Erskine scribeth thus

I suspect that under most normal conditions they'd stand more that that...