Re: How strict should my Cat5 installation be?

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Cat5 cable should not be in the same pattress as mains electricity. Only cables rated to 500V(?) insulation should be layed next to mains cable. Alternatives are to separate by 50mm, or to provide extra insulation. The last possibility might work in your case. I suspect running in plastic conduit would provide sufficient insulation for your needs.
This is not for interference protection, but for electrical safety. I've never found mains borne interference to be problematic with 100BaseT ethernet, although I wouldn't be surprised if it was bad for Gigabit.

Depends if you cock it up. If you hit the cable with a hammer, then you have a substantial chance of breaking the extremely delicate conductors. An alternative is to hit the clip in without the cable present. Then use cable ties (mucho cheapo) to tie the entire bundle of cables to the clip.
Christian.
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It's been a while since I looked, but last time I checked the IEE wiring regs prohibited running comms cable in the same trunking or channel as mains wiring.
Double patress boxes are available with spaces for two single socket outlet size plates and a separator between them, this would be an option but you would need to route the cable separately.
Personally I wouldn't use CAT5 cable for telephones anyway, but that's just me :-)
Ivor
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BS 7671 'Requirements for Electrical Installations (IEE Wiring Regulations 16th Edition' prohibits circuits of different voltage bands sharing the same enclosure, except in special circumstances.
For the purposes of the Regulations, telecommunications circuits are generally classed as being in Voltage Band I, whilst mains voltage circuits are classed as Voltage Band II.
If you would like further information on the ways in which you can solve your problem and still comply with the Regulations, post back.
Cheers,
Ross
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There's a telephony regulation for telephony circuits connected to the public telephone network which requires phone outlets to be at least 50mm from mains outlets. Sorry I don't know the reference for this.
Also, the separator in Double patress boxes does not seal the two compartments if the box is recessed behind the plaster surface any distance. (Indeed, I often end up passing earth wires over the separator, making use of just this 'feature'.)
--
Andrew Gabriel

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Me too. :-)

Personally I wouldn't do this, for safety reasons.

I would even avoid this. I've had to reroute one such cable because of hum (floorboards up again!).
The problem is, UK phone extensions use three wires and are therefore not fully "balanced", which makes them susceptible to crosstalk. You can solve this by running only two wires and fitting a "PBX master" at the end to generate the third, but this adds extra capacitance which can affect performance (and be detected at the exchange). Having said all that, such effects are slight and you won't notice any problems in the majority of installations.

Not as long as you avoid compressing the cable. Also remember to avoid sharp bends.
My final tip is to pull plenty of cables now so you won't have to do the job again (even if you don't provide sockets for them all). I've pulled three CAT5 (one for phone, one for ethernet, one spare) and TV coax to each room in the house that might get used as a "study" and de-squeaked floorboards while I was at it. Oh, and don't put the pattresses too close together - I bought some brass TV and phone faceplates and found they were bigger than the normal plastic ones and wouldn't fit!
--
Phil McKerracher
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Thanks to everyone for the replies. I hadn't even thought of the electrical safety angle, I was more concerned about mains hum. Just as well I posted.
I have been using 'dual' pattress boxes from Screwfix (ref 18949) which take two 1-gang faceplates and have a metal 'partition' screening each half from the other. However, to make it easier to get the cables in I've fed them both through one hole and knocked out the partition, doh.
I guess these pattresses used properly would comply with the regs, is that right Ross? Do you have other cunning plans which would help me out?(Incidentally the other cables belong to a 5 amp, round-pin, mains lighting circuit controlled from the light switch by the door and fed from a FCU on the ring which I thought I may as well put in while I was messing about with the floorboads).
Phil, I'm a bit worried about your reported mains hum. All the cat5 cables from the ground floor go up to the attic via a convenient shaft I found which takes the soil stack up through the building. Between two floors there is a length of 2.5mm T&E mains cable sharing the shaft. I can't think of another convenient way of routing the cat5 up through the building, so I think I'll have to risk it. If anything it would be easier to find another route for the mains cable. All these cables are dangling loosely in the vertical shaft, so they shouldn't be in very close proximity. I think it's just going to be fingers crossed (no, I can't hear a bee on the line dear).
Ivor, why wouldn't you use cat5 for telephones, am I missing something?
And as for clipping the things the consensus seems to be that it'll be alright if I'm very careful, so I think I'll be having another evening in the cellar very soon.
Martin
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CAT5 is stranded conductor whereas normal phone cable is solid. Stranded cores (at least in my experience) don't make as good a contact with the displacement type terminations on a standard telephone socket.
Just my view, your mileage and/or experience may vary.
Ivor
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AFAIK Cat5 installation cable is solid core, it's only the patch cable that's stranded (stranded being more flexible but having higher attenuation).
--
Dave Cunningham dave at upsilon org uk
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No it's not
--
geoff

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Martin Pentreath wrote: [snip]

It might be worth you looking at FTP Cat5 cable which contains a foil shielding to reduces interference. It's more expensive than the normal UTP stuff, but you may find the extra shielding reduces the potential interference from the mains cabling.
-Duncan
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Martin Ktech wrote:

No it's not I have had DECT since the start but a Tivo requires a socketed connection unless you want to spend a fortune on a wi-fi adaptation that invalidates the unit warranty.
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It would.
By default TiVos (well, UK series 1 models anyway) do not have any sort of ethernet connection. They rely on a modem that does not work well over cordless phone extensions.
TiVonet/TurboNet hacks are hardware based and give the TiVo an RJ45 ethernet port. AirNet provides WiFi by using a pc card on a small adaptor. Both require the box to be opened (and therefore kill any warranty). A ethernet to wireless bridge wouldn't help as there would be nowhere on the TiVo to plug it :-(
http://www.9thtee.net/turbonet.htm http://www.9thtee.net/tivoairnet.htm
for more info.
Darren - this got slightly off topic really :-)
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If you do Cat 5e it can be twenty times as fast.

As the custodian of several thousand runs of Cat 5, I'd question `reliable'. If a base station fails, chuck it and buy another one. Diagnosing faults in Cat 5 is a real pain. Of course, in a res environment you'll have plenty of margin for error, but one the cables get over 50m long you need to be confident they're well terminated.
ian
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Well I am sure you said the same thing about a cellphone 10 years ago and look where we are now!!!
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cellphones are not secure though, and forever dropping calls or failure to connect - in a house CAT5 is a more logical choice.
Rick
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My DECT cordless phone never drops a call (unless i walk off 200 metres down the road with it) & its as secure as it needs to be. Whoever bothers to hack its encryption is going to be mighty disappointed with the information the manage to hear!!
Paul
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You did use EN50117 double screened co-ax didn't you Phil?
--
AJL Electronics (G6FGO) : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk
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wrote:

job
three
No. Should I have?
It's a mishmash of whatever was to hand, to be honest. From memory none of it looked as if it had two screens though. Seems to work fine anyway.
--
Phil McKerracher
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You will have to replace it then at some point.
> It's a mishmash of whatever was to hand, to be honest. From memory none of

The correct, approved cable is branded every metre down its length, regardless of manufacturer. You will find that when the great analogue closedown happens, or you want digital terrestrial beforehand, your screening will be very likely inadequte. This will result in picture freeze / breakup every time your 'fridge' thermostat switches etc. Approved cable also has better loss and tilt specifications than conventional run of the mill cables.
--
AJL Electronics (G6FGO) : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk
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wrote:

of
freeze
I believe you, but at the moment single shielded coax comes from an antenna in the roofspace to the lounge, the satellite and VCR carriers are added, it goes to a distribution system under the stairs then back up to a bedroom (sharing a cable duct with active 100 Mbit/s ethernet and three-wire phone extensions), where it's decoded without any problems by a digital terrestrial receiver. Touch wood. So it's not that bad. Admittedly we're almost line of sight from Crystal Palace.
A good point to bear in mind if I have to lift the floorboards again though.
--
Phil McKerracher
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