This part of IEC 61000-4 defines the methods for measurement and interpretation of results
for power quality parameters in a.c. power supply systems with a declared fundamental
frequency of 50 Hz or 60 Hz.
Measurement methods are described for each relevant parameter in terms that give reliable
and repeatable results, regardless of the method’s implementation. This standard addresses
measurement methods for in-situ measurements.
Measurement of parameters covered by this standard is limited to conducted phenomena in
power systems. The power quality parameters considered in this standard are power
frequency, magnitude of the supply voltage, flicker, supply voltage dips and swells, voltage
interruptions, transient voltages, supply voltage unbalance, voltage harmonics and
interharmonics, mains signalling on the supply voltage, rapid voltage changes, and current
measurements. Emissions in the 2 kHz to 150 kHz range are considered in Annex C
(informative), and over- and underdeviations are considered in Annex D (informative).
Depending on the purpose of the measurement, all or a subset of the phenomena on this list
may be measured.
NOTE 1 Test methods for verifying compliance with this standard can be found in IEC 62586-2.
NOTE 2 The effects of transducers inserted between the power system and the instrument are acknowledged but
not addressed in detail in this standard. Guidance about effects of transducers can be found IEC TR 61869-103.