T
The Ghost
From a design perspective @davesparks , while I appreciate technically you are correct, using 230v as the nominal voltage in calculations gives you a safer margin of error in cable selection. This is also specified at pg 316 BS7671. Now before you say well if you do that by the time you get to 30v you would end up with 9800/say, 30v = 326 amps...Design parameters dont go down from 230v. So who of you calculate say PFC with anything but 230xCmin/Zs or ccc with anything but xw/230? And I do understand if you take the resistance of the element and R =V/I and manufacturers instructions and specifications, but still if I was designing the circuit and deciding on the cable that is the way I have been taught. And I have had this "discussion" before and taken it back and written the various viewpoints calculations up on the whiteboard from both viewpoints and the tutor in question still insisted that all design calculations assume harmonised voltage, which at the end of the day only makes things safer. Let fly the dogs of war!
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