It’s All About Torque


Ron Scollay

There are different starting applications for large motors implemented to manage the load and be gentler on the power supply. Soft starting is not always best for the motor. This presentation discusses some of the starter challenges recently investigated in the mining industry on mill motors and compressor drives and then shows some of the different variable speed drives and starting techniques on some special motors. In each case the starting and operating speed application is identified with the associated stresses on the motor. The analysis is extended to discussing the motor design considerations required for reliable operation with each of the drive and starter systems described.

Ron Scollay is a Specialist Electrical Engineer with over 30 years’ experience in the field of machines and auxiliary equipment. This experience covers general design, re-design, construction, testing and application problems of motors, generators and auxiliary equipment. Also technical audits and specialised tests and measurements to qualify condition and cause of failure with recommendations of remedial methods using contemporary design techniques and practices. On behalf of Eskom and Von Roll Isola, Ron conducted research on ‘Life Management of Motors’ and ‘Medium Voltage Insulation for Motors and Generators’ and as a result is well published.