This because of angle of magnetic flux induced in the winding of the fan. If u changed Phase neutral and condensor also it will rotate clockwise direction.
all the power system protection contolled by two instrument transformers.1.CT 2.VT CT itself has some saturation. after the sturation region CT will not sense the FAULT. so we have to design our CT upto max level fault in order to protect the power system equipments. assume a 11KV switchboard has shortcircuit current 30KA. so during this time defenetly there is voltage in order to drive this SC current. like 660V something. so if we design our CT around 900V or more then the 660V total power system will be protected from the fault. this voltage called as VKP.Knee point voltage. if you want i can give detail how design and calculate.
