09-18: Recent Development in Motor Technology Allow Direct Drive of Low Speed

Improved reliability of cooling tower systems is now possible due to a new development in motor technology. This paper will discuss the development of low speed, permanent magnet motors and how they can be used in direct-drive applications to eliminate the gearbox, NEMA motor, driveshaft, and disc couplings from cooling tower designs. A case study will be presented where an existing tower was refurbished using a direct drive motor which fit the exact footprint and height of the existing gearbox. Design considerations, performance data, maintenance history and efficiency comparisons will be presented.