There are four main types of motors; shaded pole, permanent split capacitor (PSC motors), three phase induction, and EC motors. Shaded pole motors are the least efficient motor with efficiencies between 20 ~ 30%. PSC motors are available in single phase voltage and can reach efficiencies between 60 ~ 70%. These motors require an external run capacitor that needs to be wired during installation. Three phase induction motors can reach motor efficiencies of about 75%, but are only capable of speed control with an external variable frequency drive which requires additional wiring and programing during installation. EC motors have efficiencies ranging from 80 ~ 90% which includes both the motor and drive electronics. Speed control and speed monitoring are built into the motor electronics and are pre-programmed from the factory for plug-and-play operation.