Safety and Medium-Voltage Starters

Space allocated for this article makes it important to concentrate on issues specific to mediumvoltage (MV) motor starters and forego general safety topics such as lock-out/tag-out, permitting, and job hazard analysis First a little background of what a MV starter is (Figure 1), what it is meant to do, and how it does it. As the term implies, a motor starter starts and stops a motor. How a starter accomplishes this can be quite simple, such as an across the line or full voltage starter. There are a variety of reduced-voltage starters such as autotransformer, step start, reactor start, soft start, etc., but they will not be discussed here.