III — Experience on a diversified system

INVESTIGATIONS of lightning troubles have been conducted on the distribution system of the Philadelphia Electric Company since 1921. Their purpose has been to determine: (1) magnitude and nature of trouble in various localities; (2) effectiveness of lightning arresters under field conditions; and (3) ways and means for improving service continuity. Up to and including 1929, studies were confined to the Philadelphia division. In 1930 they were extended to the entire system which includes 6 operating divisions having in service approximately 23,000 aerial transformers.