IEEE Task Force on the Effects of Harmonics on Equipment has made a wide study on this matter. The result can be summarized as follows:
1. TELEVISION RECEIVERS: Harmonics changes in TV picture size and brightness. Inter-harmonics changes amplitude modulation of the fundamental frequency.
For example, even a 0.5% inter-harmonic level can produce periodic enlargement and reduction of the image of the cathode ray tube.
2. FLUORESCENT AND MERCURY ARC LIGHTING: capacitors used in such lighting applications together with the inductance of the ballast and circuit produce a resonant frequency. It results in excessive heating and failure in operation. Audible noise is produced due to harmonic voltage distortion.
3. COMPUTERS: harmonics create problems in monitor and CPU operation. Harmonic rate (geometric) measured in vacuum must be less than −3% (Honeywell, DEC) or 5% (IBM). CDC specifies that the ratio of peak to effective value of the supply voltage must equal to 1.41±0.1.
1. TELEVISION RECEIVERS: Harmonics changes in TV picture size and brightness. Inter-harmonics changes amplitude modulation of the fundamental frequency.
For example, even a 0.5% inter-harmonic level can produce periodic enlargement and reduction of the image of the cathode ray tube.
2. FLUORESCENT AND MERCURY ARC LIGHTING: capacitors used in such lighting applications together with the inductance of the ballast and circuit produce a resonant frequency. It results in excessive heating and failure in operation. Audible noise is produced due to harmonic voltage distortion.
3. COMPUTERS: harmonics create problems in monitor and CPU operation. Harmonic rate (geometric) measured in vacuum must be less than −3% (Honeywell, DEC) or 5% (IBM). CDC specifies that the ratio of peak to effective value of the supply voltage must equal to 1.41±0.1.