Running cat 5 & telephone wires...

[JDLDIY]

I had run the telephone and cat 5 wires with some power wires, but I've thought twice about it, it might contribute to the interference I can hear on the telephone line.
Would you run them in conduit together at all though, I mean would the cat 5 cable alone cause interference on the phone line?
Cheers.

 

[AdamW]

There is virtually no risk. The phone line certainly won't interfere with the cat-5 cable, well not enough to cause any problems. The other way, there is a possibility you may hear a tiny amount of hiss on the phone line due to broadband interference from the cat-5 cable but really not enough to cause any bother.

I have cat5 and phone in the same conduits, both unfiltered (to my ADSL router) and filtered (to the phones) and I don't get any interference or problems.

I know you don't have them in the same conduits, but are you running the phone cable anywhere near any power cables?

Phone lines are bu**ers for picking up any noise they can, the design of them isn't great. You can get systems for wiring phone lines over cat-5, perhaps that might help as well as add an extra degree of flexibility?

 

[plugwash]

you could always use screened cat5 for your phone wiring

you would need to earth the screen though for it to have much effect

 

[JDLDIY]

Thanks guys. Well I'm going to go ahead and reroute the cables away from the power cables, if that's still not fixed all the interference then I may switch to screened cat5 for the phones I guess.
Got some ceilings down at the moment so I may as well do it whilst it's easily done and dusted.
Thanks again.

 

[mrscalex]

Why are you running phone cables alongside Cat5? Cat5 swallows up telephone cable and burps it out. It's very easy to run voice over Cat5.

Check this Yahoo group out which exploits the versatility of Cat5. Mains and Cat5 have no problem sitting alongside each other.

http://groups.yahoo.com/group/kat5-users/

Cat5 is a wonderful, wonderful thing. With ceilings down you have the chance to flood your house with it. 4-8 ports per heavily habited room is definitely the way to go.

All new builds should be flood cabled. What stops it is total ignorance of the technology or for those developers who are switched on, profitering as an optional extra.

Compared with mains wiring, Cat5 is falling off a log.

 

[JDLDIY]

Mains and Cat5 have no problem sitting alongside each other.

Even when running voice over it? Are you saying that if I run my phones over it I could run the cable next to the lighting/power circuit cables and not get interference?
Thanks for the reply, I will definitely be checking out that yahoo group.

 

[nstreet]

It is not good practice to run cat5 cable alongside mains cable or equipment see here for more tech info

http://www.faqs.org/faqs/LANs/cabling-faq/

 

[mrscalex]

Like many things there will be different views depending on who you talk to. But I do speak with exposure in this field.

Take a stroll into any large office and check the cable management under the desk. You will frequently find Cat5 strapped up tightly or in very close proximity to mains cables.

I spent the last 3 years of my IT career managing (at a hands on level) structured cabling installations and network infrastructure and this factor never cropped up once.

If you check the Yahoo groups forum I mentioned this is a not infrequently discussed point and even when running video over Cat5 no interference has been proved.

However I'm happy to respect anyone's view who has practical experience of this being problem!

 

[Lectrician]

Under a desk is a couple of meters, the cat5 total run could be upto 100 ish meters. If the enitre run was adjacent to mains cables, a problem is bound to arise.

Cables crossing cables should be avoided in the ideal world, but shouldnt make much odds, but best to avoid long parallel runs.

Induced voltage does exist, ask anyone who regularly works on conduit and trunking installs(with many bundled cables). When checking a circuit is dead, it is not uncommon for a multimeter to read say 30 plus volts.

Large pylons carring 132kv plus are NEVER run parallel to fences - voltage gets induced into them, and animals can suffer electrocution at only a few volts.

 

[ban-all-sheds]

Don't forget you can't put your mains cables and phone/Cat5 in the same conduit/trunking, unless adequately spaced, or separated by a barrier, as the insulation on phone/Cat5 cables doesn't have a high enough rating....

 

[JDLDIY]

Don't forget you can't put your mains cables and phone/Cat5 in the same conduit/trunking, unless adequately spaced, or separated by a barrier, as the insulation on phone/Cat5 cables doesn't have a high enough rating....

I'm definitely moving these cables away from the mains ones. Just out of interest though Ban, do you mean this is actually laid down as a requirement in the regs then?
JD

 

[JDLDIY]

Don't forget you can't put your mains cables and phone/Cat5 in the same conduit/trunking, unless adequately spaced, or separated by a barrier, as the insulation on phone/Cat5 cables doesn't have a high enough rating....

I'm definitely moving these cables away from the mains ones. Just out of interest though Ban, do you mean this is actually laid down as a requirement in the regs then?
JD

 

[AdamW]

Don't forget you can't put your mains cables and phone/Cat5 in the same conduit/trunking, unless adequately spaced, or separated by a barrier, as the insulation on phone/Cat5 cables doesn't have a high enough rating....

I am sure I have read it somewhere that also you can't put mains voltage cables in the same conduit as SELV cables. I believe Ethernet works with +/- 5V peaks, so 10V between conductors... this would count as SELV no? Or are there different regs for signal cables?

It makes sense if you think about it, if you were to run a 230V power cable amongst a big bundle of low-powered signal cables that is just asking for trouble.

 

[Lectrician]

You could run them together if the insulation on the tele/cat cable was 240v rated (it aint). I still would seperate though.

They must not share conduit or trunking, unless there is a barrier, such as compartmental trunking.

 

[dw3101]

weve got large structured cabling install here.. 10,000+ ports, + lots of fibre.

We have never had a problem with interference on cabling. Your more likely to have problems dropping packets with corrupt net card drivers or cheapo NE2000 clones.. the higher the speed the morelikey there is to be a problem.

And Ive seen 'some' electricians try and terminate CAT6, test with cat5 tester and it passes. doesnt pass at cat 6 though.. Try installing it yourself and then having to use it at proper speeds / transfers.. I dont mean home use...

Unless you are going to run something like 10GbaseT over copper, it isnt ever going to be a problem, and Ive never heard of not putting data near mains cables.. we have them inside big cabinets with three phase in them... and the cables all run on the same tray into the cab.

If its really a problem, run STP. I wouldnt try and earth it though, leave that to the computer.

David