Installation of two new 14000 hp, 4160 V motors on high-speed pulp refiners

This paper discusses the development and implementation of an engineering project to replace two 20-year-old, 12000-horsepower synchronous motors driving high-speed primary refiners. The background issues leading to the project are presented. Development of the engineering scope led to including foundation modifications, mechanical drive improvements, new vacuum switchgear, modern motor protection, automated excitation controls and new instrumentation. Power engineering design included unique solutions to the constraints imposed by a retrofit installation. Detailed planning and close teamwork led to successful project implementation during a planned mill shutdown. This resulted in improved reliability, providing the paper mill with mechanical, operational and maintenance benefits.