Cable Interference

I'm in the process of installing new wiring to the router. The cable is being recessed in to the wall but unfortunately in one place it has to pass over a number of electrical cables.

The phone cable is four strand twisted pair and it will pass at 90 degrees over three power cables, two for plug sockets and one for lights.

Is there anything I can do to shield the cable or minimise interference where it crosses the power cables?

Thanks.

Re-route it!

The best you can hope for is to minimise any effects. Keep it at 90° and as far off the power cables as you can - cables recessed in walls should be protected in some way. Are the power cables already protected by capping? Often plastic but can also be galvanised steel? If it is steel then it should be earthed and provide shielding. If not can you cap the power cables with steel?

The alternative would be to put steel capping under and over the data cables for 150 to 200 mm each side of where it crosses the power cables which you would then earth.

Not possible to reroute it. I have already moved everything I can away from the remaining wires.

The electrical cables are just in the wall with no protection. The phone cable will be touching the insulation of the cables unless I put something in between them.

There is nothing to earth anything to which complicates matters somewhat.

So use steel capping between the cables (flatten it out first) and attach the earth wire to it. Then take the earth wire to where the phone cable comes out of the wall and then find a suitable earth point close by. Any power socket or light switch will have an earth point.

I am also surprised that the power cables have no protection of any sort. Although there are plenty of cowboys who could not be bothered.

You are making the assumption that it is a modern house built to modern specifications. It was last rewired about thirty years ago.

No chance of running an earth anywhere near the phone line and the chances of digging a channel across the centre of the wall to the nearest light switch are pretty much non existent

Ideally, wiring should run vertically when it's buried in walls. Is there no way you can go up and over the power cables? If they're buried where they cross, the insulation of the network cable will need to be rated the same as the power cables - which will probably be nearer 500v rather than 240v as you might expect. I'm not sure what rating Cat5e is.

John.

Strictly speaking this would fail modern building regulations as low voltage wires should not be in contact with mains cables. The reason being that if damaged the mains voltage could find its way into the low voltage cable. There should be some capping where the cable crosses for that purpose.

The fact that the cable will cross at 90 deg means that there will be little if any interference caused from the main cables, if you are paranoid you could use a screened cable example and earth one end of the cable screen.