On Sunday, 7 July 2013 18:07:50 UTC+1, Andrew Gabriel wrote:
In article ,

writes:

I don't really understand why we don't go for 3 phase at say 800V. Let's face it: even 230V is well into the lethal zone so going higher isn't going to be any more dangerous. Plus 800 is still low enough not to arc or flashover - given remotely adequate insulation. And just think of the saving in terms of conductor! Given the price of copper (notwithstanding it's slipped back lately) I'd have thought pushing up the supply voltages would be obvious thing to do from the pov of conserving natural resources.



690V (400V to neutral) three-phase is used in some countries, suitably-wound motors can be used at 400V delta or 690V star, so easing standardisation, maybe we should consider it.


132kV, 275kV, and 400kV are used for transporting power over longer

distances across the country, particularly as generation increasingly

moved further away from consumption. (There may still be the odd 66kV

line, but most of these were phased out as the National Grid was

constructed.)



--

Andrew Gabriel

Actually there's still quite a bit of 66kV, it's been established in North-East England from the time of the 'Newcastle-on-Tyne Electric Supply Co' who built a regional grid between the wars, also for underground cables in London where 33kV isn't enough and 132kV cables would be too expensive.