Lighting in single core cable

[JohnW2]

Thinner DI tails are often used to attach a supply to a timeswitch for E7.

That would make sense, but I think the one's I've got which serve that function are probably 10mm².

Kind Regards, John.

 

[Risteard]

Used insulated and sheathed singles loads of times, and also single and earth. 1.5mm square is readily available.

 

[Paul_C]

I owned a house built in 1968 which had black sheathed singles for lighting neutral and single plus E for line. red insulated 3/029 for line, green insulated 1/044 for E, both in a grey sheath.

And there was a later metric version as well - Both 1.0 sq. mm conductors with red & green insulation. It's somewhat odd that the earth was done that way instead of being bare as with conventional T&E, but possibly it made it easier for applying the sheath during manufacturing.

 

[bernardgreen]

One big advantage of that system of wiring is the near zero capacity between live and switched live wires meaning energy efficient and LED lamps do not flicker / glow dimly when the switch is off.

The disadvantage is the magnetic field created by current in the live looped around switches is not countered by the return current in the neutral so there is a 50Hz magnetic field created. Some audio equipment and other sensitive equipment can be affected by this 50 Hz magnetic field.

 

[SimonH2]

The disadvantage is the magnetic field created by current in the live looped around switches is not countered by the return current in the neutral so there is a 50Hz magnetic field created. Some audio equipment and other sensitive equipment can be affected by this 50 Hz magnetic field.

Never underestimate he effect of that. Some years ago I got called out to one of my customers because their terminals were acting funny. All the screens in one office were "wobbling", but not all the time. After some questions - when does it do it/not do it, when did it start, etc - I tracked it down to being worst (by a big margin) when the electric air curtain heater above the shop door was running. So I asked the sparkies if they'd done any work on that circuit (RFC) lately.

Sure enough, it turned out a neutral had escaped from the back of a socket and the magnetic field made the terminals unusable - or at least unbearable to use.

But that's nothing to the effect when (on another occasion) the steel erector fired up the welder, cranked up to 11 (one of those Pickhill oil filled jobs rated for 180A), and with the welding earth attached well away from where they were welding. That turned the screen image into "snow"

Of course, few people have CRT TVs and monitors these days.