IEC Standards: IEC 61000-4-30: Testing and Measurement Techniques - Power Quality Measurement Methods.

IEC 61000-4-30 defines measurement methods for 50 Hz and 60 Hz power quality instruments. Power Standards Lab was deeply involved in developing this standard, and continues to guide its on-going revisions and updates.

This standard ensures that different PQ instruments use the same definitions, and measurement techniques, for various power quality parameters: sags/dips, swells, frequency, harmonics, flicker, etc. Older, non-compliant instruments may use their own definitions. As a result, two non-compliant instruments may produce very different readings for the same event.

1) The IEC 61000-4-30 defines the method of measurement and interpretation of results for Power Quality parameters in single and 3 phase 50/60Hz power supply systems around the world.

2) Power Quality parameters in this standard include:

- Power frequency
- Supply voltage
- Unbalance magnitude of supply voltage
- Voltage and current harmonics
- Flicker
- Interharmonics
- Supply voltage
- Dips and swells
- Rapid voltage changes
- Voltage interruptions mains signalling transient voltages (as a guide)

3) A Class A instrument within the specification will measure voltage and current to 0.1% accuracy. It also defines how a Class A instrument will calculate parameters from the measured data.

4) Accuracy will depend on method of measurement and must be made across contiguous 10 cycle periods (at 50Hz) i.e. a 200msec window. Longer term measurements are based on aggregates of each 10 cycle measurement for 3 seconds, 10 minutes and 2 hours.

5) Any instrument conforming to the IEC 61000-4-30 Class A, regardless of manufacturer will read the same when subjected to the same waveforms.

6) Voltage dips and swells and interruption durations must be based on one cycle RMS measurements calculated in half cycle steps.

7) The standard calls for Harmonics Measurements to IEC61000-4-7 (Year 2000 release) which again calls for ‘gapless’ 10 cycle determinations.

8) The standard calls for Flicker Measurements to IEC 61000-4-15

9) Class A accuracy means that the instruments can be used for:

a) Contractual applications
b) Verifying compliance with standards
c) Resolving disputes

The Dranetz-BMI PX5 and the 4400

1) The PX5 and the 4400 conform to Class A of the IEC 61000-4-30 for all parameters.

2) They also Report on EN50160 which is a standard for the supply of Electricity in Europe (and some other countries have adopted it). The Application Guide for this standard calls for an instrument that measures to IEC 61000-4-30.

3) Also used for tracking single and multiple cycle disturbances.

4) Individual Current Triggers are ideal for motor inrush tests and complete ‘Black Building' forced power cut routines.

5) The PX-5 also has a 1MSsec-1 fast sampling feature to capture Voltage Transients in detail with 14bit resolution. Current Transients are captured with 0.5MSsec-1 fast sampling.