Presented by Drew Walton, IEEE Senior, Vice President of Sales, intellirent, Division of Electrorent

As one of the only moving parts of a power transformer, on-load tap-changers (OLTCs) are one of the main causes of failures in power transformers. These failure modes can be divided into three major categories: 1. Mechanical system failures (mainly related to the transmission system), 2. Damages produced in the main current path caused by wear or damage of the contacts, 3. Problems in the insulation system.