Currency fluctuation, also called voltage fluctuation, is caused primarily by a reduced quality of power supply stemming from corroded or loose wire connections, which may produce power surges, brownouts, blackouts and spikes. Currency fluctuations are typically brief, and may arise without warning. These fluctuations may produce flickering and dimming lights or cause lights to become brighter.
Currency fluctuations may stem from problems with wires on the transmission or receiving site of electricity. The source of voltage fluctuation may come from power lines or homes and businesses. Sometimes the symptom produced by currency fluctuations indicates the cause of poor power supply.
Dim lights, according to Northern Power, may indicate that voltages are too low. This is typically caused by a network overload that results in reduced output. Dimming lights may also be caused by loose connections or by improperly sized conductor wires carrying power to a house or office, which reduce power supply when they are too small.
Power surges and power spikes are generally caused by lightning, power switching on electrical lines or from household appliances using excessive amounts of electricity during operation. Less commonly, power fluctuations arise from downed tree limbs and strong winds, but may also be caused by interference from birds, squirrels and other animals on lines.