the most simple question

[rumrunner]

Good answer dadoftwo,i think your right,better wait untill shakey agrees,before getting too excited but i think your rite ,
atvbitwww

 

[supasparx]

At a guess, because flex is stranded and the only real way to control the strands is to enclose them in insulation.

Regards

Yes, you've just taught me to engage brain before keyboard.

 

[rumrunner]

Not at all ,if everyone engaged there brain before key board then no one except maybee shake would post anything.
its the questions ,such as yours ,which although the answers are not immediately apparent ,but teach us the intricaces of our complex trade
and remember every one.f you dont know ASK i
ATVBITWWW

 

[Shakey]

Yeah I've come across this myself.

I tend to agree with the suggestion that the earth conductor is uninsulated to give better fault indication. But if that is the case, why is the earth in flex insulated?

I know flex is alot less likely to come in contact with a nail or screw but it is prone to being pinched, trapped or general sheath damage.

Because: Flat twin & earth is exactly that - flat, and should be laid as such. so if a nail goes through it it is almost certain to hit a live conductor and the bare cpc.

with flex, it can be laying anyway on a surface, and a lot of flex is actually toroidal in structure (it curves in a helix like fashion throughout its length) so you could never be sure as to what conductors you will hit.

plus flex is far more prone to damage because its used for equipment supplies etc, and needs the additional protection. Tw&E of course, is 'static' when installed.

job done