The importance of Class A for the Coordination of Power Quality Levels

Power Quality measurement is still a quite embryonic market although there are hundreds of manufacturers around the world. Whereas basic variables like RMS values of voltage and current are well defined, some power quality variables are not.

This has led to a situation, that different instruments might show different results. The standard, issued by the International Electrotechnical Commission, IEC 61000-4-30 defines for each type of parameters the measurement methods to obtain reliable, repeatable and comparable results.

The objective of this paper is to explain how to measure the most important parameters and to give a little outlook how this standard might evolve and effect the way you need to measure Power Quality.