International Drive Distribution Loop Protection

Designed and installed in the late 1990s, the International Drive (I-Drive) system was one of the first examples of distribution designs that provide high reliability and availability for critical business customers. After years of successful operation, aging equipment and unintended consequences of maintenance updates contributed to a few misoperations and unwanted outages for these customers. This was the driving factor in taking a critical look at these systems to evaluate the current state and determine appropriate upgrades and operational changes. This paper will cover the history and background of the I-Drive design, motivations for the modifications that have been implemented, and the events and their causes/solutions. It will also go into detail about how the special scheme works, and what work has been done to keep the I-Drive system as reliable as possible over that past twenty years.