He needs a larger pulley if going from 60 to 50 ( as a motor pulley ). It needs to be 20% bigger because the motor turns slower on 50 Hz. 6/5 to be exact.
On Sat, 10 Nov 2018, Chuck Guzis via cctalk wrote:
No argument there--but the size increment is pretty small. Consider that a typical motor pulley is about 19 mm in diameter, so a 20% increase would be only about 23 mm.
Depending on the drive, WHICH pulley should be changed?