electric and aerial cable

[Neil]

Good morning, Can anyone see a problem running electric and television cable through the same conduit? Would reception get interference? Thanks Neil

[john]

Yes.

[ctl]

I can see a problem but it depends on what you are using. If the coax is feeding a digital TV box then each time a light goes on and off your picture will crack up. Then there is a problem of inducing a voltage into the coax. You will also get like a low frequency mains hum.

[Neil]

My brother wants to run an electric cable and tv cable,from present tv position, to new position about 3 metres away. He wants to run the electric an aerial cable together, to save chasing two runs of plaster/ blockwork out. Hope this is a bit clearer. Thanks Neil

[Andrew Gabriel]

If you are refering to an aerial cable running at VHF or above, then you are very unlikely to get interference from the mains. However, in order to conform to the wiring regulations, both cables must be designed for use at the higher voltage when sharing conduit, so you'd need to find aerial cable rated for mains voltage use.

[Ian Stirling]

You most certainly will not get low frequency mains hum. Quality coax will be less likely to get interference.

[Mike Harrison]

You could always try it first - tape/cable-tie an equivalent length of the cables together ( or put them in some conduit if that's what you'll be using), lay them out in as straight a line as you can (i.e. don't coil them) and see if you observe any interference whan appliances are turned on/off - especially noisy ones - hairdryers, hoovers, drills etc.

[Bob Eager]

As per the Wiring Regulations, you can't. Unless either:

a) they are separated by an insulating divider rated at mains voltage b) the TV cable is actually rated for mains voltages (unlikely)

This is a specific requirement, for legal and safety reasons.

[Dave Stanton]

You have seen Bob Eagers post ?

Dave

[Jim Gregory]

The lower cut-off for the band used in TV equipment receiving from your coax is much, much higher than 50Hz, more like 70MHz or even 270MHz. So no hum will be noticed - as it gets ignored. You do not specify what traffic is flowing through the mains cable. Any momentary surges and back-Emf spikes across the adjacent mains may get registered as blips, depending on the design of the input circuitry in your set/vtr. But if sharing a conduit for just a few feet, it's so unlikely.

[The Natural Philosopher]

Yes. Interference is one issue, and lightning strikes on your radio aerial that end up in your mains circuit cause yet more damage..been there..done that..

[Dave Liquorice]

Not to mention that mains and anything else in the same conduit is against the regs.

[David Hansen]

On Wed, 25 Jan 2006 20:12:48 +0000 (GMT) someone who may be "Dave Liquorice" wrote this:-

Leaving aside safety services, it is against the regs if all cables are not insulated to the highest voltage. This insulation must be maintained throughout, including joints, which makes separate conduit, or multi-compartment trunking, attractive in many situations.