A few common causes of power quality issues are:

  • Voltage Sags (10% -90% voltage reduction for less than 1 minute)
  • Voltage Swells (110% or greater increase of voltage for less than 1 minute)
  • Bad grounding
  • Bad neutral connection
  • Harmonic distortion
  • Equipment switching on or off
  • Failing equipment

Most power quality issues are created from some piece of equipment, however it can be difficult to find the source of the problem.