Survival of the fittest

This article discusses the two motor designs namely weather-protected type II (WPII) and totally enclosed fan-cooled (TEFC) motors specifically employed in a variety of harsh, contaminated environments of the petrochemical industry. These two motor designs are fundamentally different in everything from cooling methods to maintenance. Although there are many motor applications within the industry in which both enclosures would be suitable, totally enclosed fan-cooled motors from 250-2,000 hp typically perform better in the harsher environments. Their increased reliability leads to reduced downtime caused by repair or replacement and the price differential can most often be recouped through lower life-cycle costs of the motor