ABSTRACT
Wind, fungi, ultraviolet light, tree branches, whole trees, and animals of various sizes—each of these can stress overhead distribution lines, electrically and/or mechanically. This chapter explores several programs or options that utilities use to maintain and/or improve the performance of their distribution infrastructure. Hardening of overhead infrastructure or resiliency improvements to reduce damage and reduce times to repair can reduce customer impacts. Trees are the source of many reliability issues on circuits, and vegetation management is expensive. For most utilities, vegetation management is by far the largest maintenance item in the budget. Understanding how trees cause outages and damage will help utilities design more tree-resistant lines and help utilities more efficiently manage vegetation maintenance. Niagara Mohawk used several investigations to restructure its vegetation management programs for distribution systems. The chapter focuses on bushing guards and wire coverings—the most common and effective animal-control technologies.
