Load Tap Changing with Vacuum Interrupters

A comparison between the four common types of conventional load tap changing (Itc) mechanisms for use on power transformers and the introduction of a new mechanism using vacuum interrupters for the arcing function is presented. Design parameters for the present and new equipment are discussed along with an understanding of some new problems associated with operating speeds, interrupter life, and voltage transients. The advantages for both the manufacturer and the user of load tap changing, using vacuum interrupters, are identified. These include increased life, smaller size, fewer inspections and servicings, and fewer equipment types.