Specification and Evaluation of Large Induction Motors in High Inertia Applications

The majority of rotating equipment applications in industry are driven by induction motors in a full voltage non-reversing (FVNR), fixed single speed set up. Certain applications involve driven equipment with high inertia driven by large and expensive motors rated for several thousand horsepower. Such motors fall into the API 541 category of special design. The electrical engineer representing the equipment purchaser and end user has the responsibility to specify the motor performance requirements, evaluate motors offered by suppliers as part of rotating equipment bids, and after purchase award, review and approve design documentation submitted by the supplier. Motor starting performance, power system characteristics and motor protection relay set up, being interdependent, require close scrutiny