Maximizing large drive availability

Drive-system availability is a function of both the reliability and repair time of the drive, motor and associated equipment. This is true at the system level, as well as at the component and subcomponent level. To achieve high availability, the reliability of each component as well as the drive itself must be reviewed. Various design methods can be used to improve reliability, such as modeling, component de-rating and margins, component redundancy, component qualification testing, and system qualification testing. Although a good design minimizes the need for repair, the possibility of repair still exists and must be planned for in the design. The repair of large drives can be more complicated than that of smaller drives since it is not economical to replace a complete unit. For this reason, it is necessary to utilize computer-based automated troubleshooting programs in the drive diagnostics design in order to quickly and accurately identify a problem module. The equipment must then be designed to allow rapid replacement of that module. Design, along with a number of other support factors that are covered in this article, will lead to high availability.