Cooling Tower Motor & Controls

A Cooling Tower is a heat exchange system that removes waste heat from a process system fluid, usually water. Cooling towers are used in both commercial and industrial applications. The mechanical components of a cooling tower fan are made up of Motor, Gearbox, Drive Shaft, Disc Couplings & Fan impeller. The motor speed is typically 1,800 rpm’s. Fan speeds are much slower and are determined by the diameter of the blades to keep the blade tip subsonic, typically around 90 to 230 rpm’s. In cooler climates the fans can be reversed to prevent freezing during the winter months. Average cells are 14 to 28 feet in diameter.

Improvements in system safety, reliability, efficiency and noise reduction are now possible with the introduction of new motor and drive technology applied to cooling tower applications. The same electric motor and control technology that is being used to power today’s most sophisticated hybrid vehicles is now being adapted for cooling tower drive applications. Advances in motor power density using laminated steel frame construction combined with high flux strength permanent magnet salient pole rotor technology results in a high torque, slow speed, low profile motor that is mounted directly to the fan and operates at variable speed to maximize system efficiency. Permanent Magnet Rotor (PMR) construction using high flux strength Neodymium Iron Boron (NdFeB) magnets allows the motor to be manufactured in a compact form factor. The same basic motor design requirements for a hybrid vehicle of high torque, efficient, low weight, reliable, quite and highly compact also apply to the cooling tower application as well.

The ACS880 +N5350 Cooling Tower Drive Controller and RPMAC Permanent Magnet motor are designed to drop directly into existing gearbox mounting patterns. Retrofit can be accomplished in under six hours! The biggest improvement to the fan drive efficiency is seen with the elimination of the gearbox from the system. Permanent magnet control greatly increases operating efficiencies even under lightly loaded conditions typical in fan applications at low speeds. Temperature rise in the motor is also considerably lower making for a power dense package and increase motor life over conventional induction motor systems.