Troubleshooting today's variable speed drives (VSDs) demands intimate knowledge of the systems in which they are installed, of the motors at the business end of the drive, and especially of the controllers that run them. This course will focus on the VSD controller, both as a troubleshooting tool and as a system component that may need troubleshooting itself. The course will examine troubleshooting from the controller, including a review of basic safety procedures, and the selection of test instruments. In addition, it will describe how a controller can help locate many of the most common operating problems.