The cause of an outage is not always obvious or immediately visible. Before repairs can be made, O&R crews must first inspect the lines and equipment to find the specific problem and then ensure the area is safe before repairs can begin.

Common Causes of Power Outages

Lightning is a frequent cause of localized power outages during the summer months. Fuses and devices called lightning arrestors are installed thoughout our distribution system. They are designed to protect our lines, in most cases, from serious damage; still, it takes time for field crews to locate affected pieces of equipment and make the needed repairs.

High winds mainly from thunderstorms, but sometimes from tornadoes and hurricanes, are often the cause of both local and widespread outages. Damage generally occurs when trees or tree limbs fall onto our power lines.

Ice storms can create a heavy buildup of ice on power lines and trees. In rare cases, the buildup can be so great that wooden utility poles and metal lattice transmission towers collapse under the enormous weight.

Heavy rains can cause flooding that damages both above-ground and underground electrical equipment. Flooding may also make travel difficult for repair crews.

Falling trees and tree limbs, resulting from any of the above severe weather conditions, is the single leading cause of power outages during storms. While we cannot prevent trees from toppling into our power lines due to high winds, we do try to limit tree interference through our regularly scheduled vegetation maintenance program. By redirecting tree growth away from power lines, we can limit damage that could be caused by severe weather.

Vehicle and construction accidents are not an unusual cause of power outages. Motor vehicle accidents can result in broken poles, causing power lines to fall and short-circuit. Also, construction crews occasionally contact overhead electric lines with tall cranes, high-boy lifts, backhoes and dump trucks, creating life-threatening conditions for those involved as well as power outages in adjacent areas. In winter, O&R's green pad-mounted transformers, usually placed within a few feet of the curbing in some housing developments or commercial areas, can be damaged by snow plows and vehicles sliding off the side of a road.

Small animals, typically squirrels, raccoons and birds, can short-circuit certain pieces of pole-mounted equipment, such as transformers and fuses. Specially-designed animal guards are installed where possible to prevent this type of outage.

Equipment failure can take place on the electric system. This can be created by exposure to the elements and high electric loads over time. To increase reliability, O&R routinely monitors loads on its system, constantly balancing and upgrading circuits to meet higher demand. Older wooden poles are regularly checked for deterioration from weather, insects and woodpeckers, and replaced when necessary. Our 602 miles of overhead transmission lines and rights-of-way are patrolled monthly by helicopter. Critical electrical connections on our transmission and distribution systems are monitored for higher-than-normal temperatures using infrared measuring devices.

Metal foil balloons look harmless when tied to picnic tables for backyard get-togethers. But, if helium-filled ones are released, they can get caught in overhead electric wires and knock out power to an entire neighborhood. They're also a serious safety hazard, especially if the string or ribbon is wet.

Inside your home or business, outages or other disturbances can be caused by faulty or loose electrical wiring; poorly grounded electrical appliances; faulty circuit breakers or improperly sized fuses; and large appliance motors cycling on and off.