Coax, CAT5e & 2.5mm T&E in the same chase

[DarrenThomas]

I need to run some new sockets as well as add a TV socket and network outlet in the living room. I have read on here that LV cable needs to be 50mm from data cable unless it is run in conduit/trunking/etc but does standard plastic oval tube count?

If not I'll have to have a bit of a think!

 

[Click-Sure]

further away the better in my view when running data and power cables paralell to each other.

Running your power cables in plastic conduit won't help (the cable is allready coated in a couple of layers of PVC, remember?)

Earthed steel conduit would do the trick niceley, as would a cable within integral earthed metal containment such as SWA or Ali-Tube.

 

[plugwash]

There are two considerations when running power and communication cables together, safety and interference.

The safety issue is that if the cables were to become damaged dangerous voltages could get onto the communications cables. This is afaict the main reason that the regs insist on either at least one of 50mm of seperation, seperate sections in conduit/trunking or all cables insulated for the highest voltage present.

Intereference really requires metal screening to stop it but I doubt it will be a problem on a domestic installaion.

 

[Hibbo]

So different PVC conduits, same chase, is OK then? (From a safety / regs point of view)

 

[GaryMo]

Yes but maintain >50mm separation when entering and exiting the conduits.

 

[sjwkmje]

further away the better in my view when running data and power cables paralell to each other.

Running your power cables in plastic conduit won't help (the cable is allready coated in a couple of layers of PVC, remember?)

You can run them together but the CAT5/CAT6 needs to be screened (foil twisted pair) and earthed at one end (Faraday screening). Most decent coax these days is already screened. Other than that there has to be a separation between mains cables running parallel with the data cables.

The way I did it in my parents kitchen was two peaces of 20mm galv ducting to a double single metal clad back box sunk in the wall ( You know the type the one where you can fit two single accessories side by side). One peace took the coax and CAT6 in my case and the other a single peace of 2.5mm t+e for a socket earthed the back box so the conduit was earthed. As a precaution I used an earth nut as well. One side a single socket for the tv the other side a MK grid with a screened F plug module and screened cat6 module. Works great. And there is no need for an RCD at the source either if the rest of the cable runs in the floor. Its not to expensive to do if you have the tools to work on conduit.

Adam

 

[electronicsuk]

You can run them together but the CAT5/CAT6 needs to be screened (foil twisted pair) and earthed at one end (Faraday screening).

Only if it's STP/FTP cable. Even with UTP cable, ethernet is pretty robust. It's not recommended, but you could easily run data parallel to a mains cable for many tens of metres and very rarely experience any problems.

Most decent coax these days is already screened.

I'd like to see you find an unscreened coax cable

 

[GaryMo]

He probably means the foil which sometimes sits, between the outer braided shield and the inner dielectric insulator.

 

[sjwkmje]

You can run them together but the CAT5/CAT6 needs to be screened (foil twisted pair) and earthed at one end (Faraday screening).

Only if it's STP/FTP cable. Even with UTP cable, ethernet is pretty robust. It's not recommended, but you could easily run data parallel to a mains cable for many tens of metres and very rarely experience any problems.

Most decent coax these days is already screened.

I'd like to see you find an unscreened coax cable

That's why I said FTP. STP screened twisted pair will do the same job.One will have a braid one will have a screen. The excel CAT6 LSOH FTP stuff actually has a screen around the entire pairs and then individual foil twisted pairs but this stuff is mega expensive.

If you look at decent RG58 you have an inner solid core an outer dielectric insulator and then a braided foil around the insulator. Some then have another insulator and a solid screen around that. RG12 is the same I think. Some cheaper stuff you get the braided foil dielectric but not outside screen. Screen been a complete screen to stop stuff like cross talk etc. Look at the coax Sky use it has a screen and braid. That's the stuff I was referring to not standard unscreened coax.

Adam

 

[electronicsuk]

If you look at decent RG58 you have an inner solid core an outer dielectric insulator and then a braided foil around the insulator. Some then have another insulator and a solid screen around that. RG12 is the same I think. Some cheaper stuff you get the braided foil dielectric but not outside screen. Screen been a complete screen to stop stuff like cross talk etc. Look at the coax Sky use it has a screen and braid. That's the stuff I was referring to not standard unscreened coax.

Adam

Adam, I think you're getting your terms confused. The outer grounded metal layer, whether's its braided, foiled or a combination of both, is still the screen. It's called that because it's purpose is to serve as a screen, regardless of its construction. You would not get a 'braided foil dielectric', as the dielectric is the insulator between the inner core and the screen, and is not a metal conductor.

My bad on the FTP, you did indeed mention it. Sorry.