11000/433 tx

Back in the dark ages, when Her Majesty's Volts came at a pressure of 240 nominal, the transformer end of the street was often set to the 250V tap, so that the folk at the far end never got less than 220, even in winter.

 
However, as far as I know, no-ne ever called that 433, though of course within rounding, it was. Other figures, 440, 420 and 415 were common, and since harmonization, 400.

All but the smallest of Tx have taps, typically in steps of 2.5%,  anyway, as the 11kV side is not that constant across the country either !

There is a 'roots of 3; trend on LV, so 230/400/690/1k3 are all LV side standards. but the HV (does anyone say MV?) stuff was not so simple  3.3/ 6.7/ 11/33

I agree it seems an odd choice, 

Mike,

Back in the dark ages, when Her Majesty's Volts came at a pressure of 240 nominal, the transformer end of the street was often set to the 250V tap, so that the folk at the far end never got less than 220, even in winter.

 
However, as far as I know, no-ne ever called that 433, though of course within rounding, it was. Other figures, 440, 420 and 415 were common, and since harmonization, 400.

All but the smallest of Tx have taps, typically in steps of 2.5%,  anyway, as the 11kV side is not that constant across the country either !

There is a 'roots of 3; trend on LV, so 230/400/690/1k3 are all LV side standards. but the HV (does anyone say MV?) stuff was not so simple  3.3/ 6.7/ 11/33

I agree it seems an odd choice, 

Mike,