Lightning-caused distribution circuit breaker operations

As a part of EPRI Research Project 2542-1, Characteristics of Lightning Surges on Distribution Lines, a coincident lightning events detector (CLED) was developed, tested, and installed in a test area on the Florida Power Company distribution system in St. Petersburg, Florida. The CLED provided the data to determine the number of lightning-caused circuit breaker operations for the first time. During the 3-year recording period, a total of 546 faults causing circuit breaker operations occurred on the seven circuits in the test area. Of these faults, 415 (or 76%) were temporary faults. A lightning strike was coincident with 42% of the temporary faults. Improper operation of line fuses was traced to the absence of lightning arresters at line fuse locations