Central Maine Power Co., a subsidiary of Iberdrola USA, began its summer inspections of its transmission lines earlier this month. The annual inspection flights are an important part of the utility’s efforts to ensure safe, reliable delivery of power to homes and businesses throughout its service area.
The utility inspects its transmission system using a helicopter equipped with infrared equipment to detect “hot spots” that might need attention.
“Our lines are exposed to the weather all the time, and extreme temperatures and precipitation can take their toll on switches, clamps, insulators, and other equipment,” says CMP spokesperson Gail Rice. “These devices often heat up if there’s been minor damage or wear, so inspecting the lines with infrared equipment lets us find and fix problems before they cause a power outage.”
CMP owns nearly 2,500 miles of transmission line (about the same distance between Portland, Maine and Portland, Oregon) and inspects the system annually. The utility also does aerial patrols following severe storms or when its Energy Control Center detects an abnormality such as a momentary outage from a lightning strike or a change in voltage.
Each spring and fall, CMP also does a visual inspection of all of its transmission rights-of-way from the air. These flights help spot potential problems with equipment, as well as signs of unauthorized use.
“When people encroach on our rights-of-ways with heavy equipment during logging and other operations, it poses a threat to both system reliability and public safety,” says Rice. “We also have had problems with people using our rights-of-way for all-terrain truck ‘mud runs’ and to dispose of old appliances, building materials, and even cars. This unauthorized use is illegal, bad for the environment, and unfair to nearby homeowners who should be able to enjoy some peace and quiet around their homes.”