Natural Causes
Weather
Strong storms can cause trees or branches to fall and tear down power lines; tree limbs brushing or resting on lines can cause short circuits and blown fuses. Lightning strikes can damage substations, power lines and equipment. High winds, heavy rain, snow and ice also can damage equipment and cause outages.
Heat
- There are several reasons why high temperatures can cause outages.
- There is also the possibility of scattered outages resulting from equipment overheating. Transformers, for example, can fail from overheating. Transformers are built to dissipate their heat, but in extreme weather conditions such as we're experiencing, there is no ability to cool because temperatures remain high throughout the night. Problems are also magnified in the confined spaces of an underground electrical system. For example, if there is a flaw or crack in the cable insulation, a short circuit could occur as the cables expand from the heat.
- Increased demand for air conditioning means more electricity flowing through power lines. This causes them to heat up and expand or sag, and in some cases they sag into tree branches, causing a short circuit.
- Electricity loads combined with high temperatures cause transformers to heat up, sometimes reaching critical levels that if uncorrected would permanently damage the equipment. The equipment will automatically and safely shut down to protect itself and other equipment.
- High current causes stretching of cables, switches and other equipment and can increase the size of minor flaws in insulation or connections.
- Electric equipment can be weakened by lightning strikes and circuit failures, making it more susceptible to an outage as it can no longer withstand the increased flow of electricity during periods of high demand.
Critters
Small animals, like squirrels, sometimes chew into lines or come into contact with a piece of equipment and an energized line, resulting in their untimely demise, and an interruption of electric service for you.
