Common Voltage Distrurbances

The following events are the most common form of voltage disturbances:

Transmission line operation caused by animals, weather, unforeseen equipment failure.
Voltage disturbance on one distribution line affects an adjacent distribution line on the same substation transformer.
Substation circuit breaker opens and closes momentarily to allow fault on distribution line to clear.
Severe weather, equipment failure, tree damage to conductor wires, vehicle hits distribution poles, or animals.
Commercial facility disturbances: copy machines, air conditioners, large electric motors, electric welders.
Residential facility disturbances: refrigerator, air conditioners, electric motors, improper wiring and grounding.