• It will operate at a constant speed from full load to no load
• It will operate at the speed of the rotating magnetic field
• Stator windings similar as other types of three phase motors
• Wound rotor with same number of poles as other stator
• An independent field is established by a rotor energized by direct current through slip rings mounted on the shaft
• At running speed, these fields lock into one another magnetically so the speed of the rotor is on step with the rotating magnetic field is the stator
• A starting winding called amortisseur is embedded in the pole face of the rotor
• The induction effect of the starting winding provides the starting acceleration
• At 95% of the synchronous speed DC is applied to the rotor, which will bring the rotor up to synchronous speed
• Used for applications involving large, slow machines with steady loads and constant speeds, including compressors
