Youve got this wrong, I do understand the workings......its the simplifying it down on paper so I can explain it, there is nothing wrong with trying to figure this out so im better prepared surely?? The phase rotation was lectured during the course but theres not much of it in the course books, the interview is for a permit to basically pull the fuse at the service & replace the meter. There is no way I could of blagged it this far without understanding the basics im afraid & your way of if thats what you think.