The peak value of the sine wave of 230 - 240 - 250 volts supply is.
324V - 338V - 352V. ( could be a reason why that voltage level was chosen )
Standard 230 V. mains cables are dc tested at 500 Vdc with a megger anyway.
The other things with rectified ac makes sense. 230 x 1.41 = 324 V in case of switch mode powersupplies.
I don't think dc is a good option at all.
To make and especially break a dc load need special heavy duty switchgear, because the arc doesn't extinguish 100 times a second as with ac.
A standard lightswitch wouldn't last long at all.
It's always an interesting topic to discuss these alternative options.
Chhers Ray.
