One of the possible causes is lighting, and in particular, electronic ballasts. Other equipment can also generate harmonics including variable frequency drives, personal computers, programmable controllers and solid state switching devices. Harmonics can also enter a facility in from outside, a neighboring facility, for example. High harmonic distortion can have negatively impact a building's electric distribution system. It can generate excessive heat in motors causing early failures.
Heat also builds up in wire insulation causing breakdown and failure.
Increased operating temperatures can affect other equipment, causing malfunctions and early failure. Power quality experts can conduct a survey of the facility to determine the cause of harmful harmonics and recommend solutions. Power filtering devices are available. Also, sometimes, lighting circuits can be isolated from other circuits in the electric distribution system. High harmonic distortion levels are most common in hospitals, industrial facilities and offices with a high concentration of computers, although any building can be a candidate.