User`s manual

24
Wiring Chapter 2-2
Harmonics
■ Definiton
Harmonics consist of electric power produced from AC power and alternating
at frequencies that are integral multiples of the frequency of the AC power.
The following frequencies are harmonics of a 60- or 50-Hz commercial power
supply.
Second harmonic: 120 (100) Hz
Third harmonic: 180 (150) Hz
■ Problems Caused by Harmonics Generation
The waveform of the commercial power supply will be distorted if the
commercial power supply contains excessive harmonics. Machines with such
a commercial power supply will malfunction or generate excessive heat.
Basic frequency (60 Hz)
Second harmonic (120 Hz)
Third harmonic (180 Hz)
Basic frequency (60 Hz) Third harmonic (180 Hz)
Distorted current wave
form