Reducing energy consumption and increasing energy efficiency are key strategies for mitigating future energy problems. In this connection, the EU has specified requirements for the environmentally compatible design of energy-using products in Directive  2009/125/EC. The aim of this directive is to reduce the environmental impact of products during their entire life cycle. Along with energy consumption and efficiency, the maximum permissible standby power is specified for many devices. For example, since 2010 the maximum permissible power consumption of household and office equipment in standby mode is 1 W, and this will be reduced to 0.5 W in 2013.

 

Energy consumption must be measured using reliable, accurate and reproducible methods corresponding to good engineering practice in order to demonstrate CE conformance. The corresponding technical requirements are specified in IEC 62301. The maximum allowable measurement uncertainty is 2%, or 0.1 W for measurements below 0.5 W. As standby circuits usually have a very low power factor and a high crest factor, the accuracy of the instrument must be up to two orders of magnitude better than this.

 

The LMG95 single phase precision power analyzer and the LMG500 multichannel precision power analyzer from ZES ZIMMER are well suited to making such measurements. Specifically for testing CE conformity, ZES ZIMMER has now released the new CE Test Standby software. It configures the instrument, specifies the test procedure, and generates a standard-compliant test record. It acquires the instantaneous power, average power, averaging time and test duration, and it monitors the frequency, voltage and waveform (crest factor and THD). The measurement uncertainty is calculated for every result and included in the test report.

 

ZES ZIMMER also offers suitable sensors, including the SH100 series of shunts for currents up to 1 A, which provide device protection and better scaling, as well as measurement adaptors for integrating the unit under test into the measuring setup.

 

Image: ZES ZIMMER

 

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