tagoheer
May 14, 2009, 02:48 AM
Why we use a capacitor in single phase but not in three phase motor?
Scleros
May 14, 2009, 05:01 AM
One purpose is to delay energy to one of the motor coils to increase starting torque in single phase motors. The nature of 3 phase power provides the necessary torque.
See Wikipedia: AC motor (http://en.wikipedia.org/wiki/AC_motor), Wikipedia: Electric Motor (http://en.wikipedia.org/wiki/Electric_motor), HowStuffWorks: How Electric Motors Work (http://electronics.howstuffworks.com/motor.htm), and All About Circuits: Single-phase induction motors (http://www.allaboutcircuits.com/vol_2/chpt_13/9.html).