Originally Posted by
fletty
Hi SB, 'normal' AC electric motors (ie not DC nor variable speed) run at fixed nominal speeds related to the number of magnetic 'poles' in the design. 2 pole motors run at nominally 3000rpm, 4 pole at 1500rpm (eg your 1428rpm), 6 pole at 1000rpm and so on. BUT, the US electricity supply is at 60Hz (= cycles per second) wheras most of the World is at 50Hz and so everything electric in USA goes 1.2 times faster! 1500 x 1.2 = 1800 (and hence their 1780rpm).
As the next step would be to (our) 3000rpm, it is a good idea for everyone to stay with our 4 pole at 1500rpm and spend the extra bit of time enjoying the process! :roll:
fletty