We've got to run a Cat5/6 and a phone cable from the house to the gates - a distance of about 27m.   The cables will terminate at the gate controls which is next to the new supply point and meter.    Sparky is suggesting that for a 27m run we should be using 16mm 2 core armoured with a 16mm CPC in the same duct, earthing the SWA as a secondary bond ( @ProDave, @Onoff, @Steptoe Comments welcome...)   Now if it was me, I reckon that the EMF of that suitably earthed SW