Following are the factors to be considered to select electrical drives for an application:
1) Load torque required at normal speed matches with available torque of motor. 2) Break down torque or pull out torque or maximum torque must match with the maximum torque requirement by load. 3) Starting torque of motor must be more than that needed by load. 4) The duty or load cycle of the motor determines the motor’s thermal loading; hence it should be such that sufficient time is available for cooling between the cycles. 5) The torque speed characteristics available from the motor must match the requirements of the load. 6) The environment/atmosphere in which the motor is to be installed govern the motor operating characteristics required. Eg. Corrosive atmospheres, dusty atmospheres, high temperature spaces need properly chosen motors for drives. 7) Cost of the motor plays an important role if a range is available. 8) Easily procurable, quick and easily serviceable motors are normally preferred. Standard motors are normally preferred. 9) Normally while selecting motors its performance is verified from the test certificate. 10) The power factor (reactive power drawn) and performance between 70% load to 100% load are considered. A motor having good characteristics in this regards will be always be preferred. 11) If selecting an energy efficient motor the cost benefit analysis over the long run must be worked out.