Special Project to Determine Polymer Distribution Arrester Failures

Florida Power & Light (FPL) experienced intermittent line tripping and breaker lockout on their overhead distribution circuits. Troubleshooting by repair crews determined that these trips were caused by distribution lightning arrester failures and subsequent tracking of their mounting brackets. The problem was not initially considered an issue because the incidents were believed to be approximately 30 per year system-wide. Investigation found the actual number of incidents to be more than 500 per year.