Energy consumption in low-power and standby modes is now recognized as an important issue due to the increased awareness that energy resources are becoming more limited and because the demand for energy-saving household electrical appliances continues to grow.
Internationally recognized standards IEC62301 Ed2.0 (2011) and EN 50564:2011 define standby mode as the lowest energy consumption of an appliance not performing its main function, when connected to the mains. Additionally, IEC62301 Ed2.0 (2011) defines the test methods and requirements for both the mains supply and the test equipment. Appliances that typically fall under the umbrella of these standards include those that turn on almost instantly without a delay for warm-up, such as smart home devices, TVs, anything that get switched on with a remote, and even some plug-in chargers for cell phones and laptops.
Figure 1. Examples of devices that use standby power.
Manufacturers of domestic electrical appliances and related equipment that seek to develop and market products that are certified as operating with high efficiency and minimum standby power consumption must perform strict standby power testing as determined by government-backed programs such as ENERGY STAR and the EU Eco Directive.
As these energy efficiency and environmental protection programs continue to expand, their requirements become more stringent, resulting in a drop in the standby power level necessary to confirm compliance. It is crucial that design and test engineers choose highly accurate power measurement tools to confirm that their devices meet these requirements.
The IEC62301 Ed2.0 (2011) standard defines the relevant test conditions for accurate measurement of standby power. Requirements for the measuring device include the ability to measure low current and power factor, crest factor, harmonic content, and energy consumption over time if the power consumption fluctuates. For this reason, a power analyzer is typically used to measure standby power.
For easy and accurate measurements, Yokogawa Test&Measurement’s Power Consumption Measuring Software connects with WT series power analyzers and satisfies the requirements of IEC62301 Ed2.0 (2011), for household electrical appliance standby power measurement, and EN 50564:2011, for electrical and electronic household and office equipment low power consumption measurement.
A power analyzer can be connected to the software using GPIB, Ethernet, USB, or RS-232 by selecting the appropriate power analyzer and connection method shown on the Connection screen. Click Device Search, select the proper instrument, and then click Connect to establish the connection.
Figure 2. Connection screen showing a successfully connected power analyzer.
The Settings screen allows users to make selections based on their specific testing requirements including the region, standard, measurement period, and more. The region selected determines the rated voltage and frequency. Users can also specify stability judgment algorithms to include linear regression, cumulative average, and three-section compare algorithms.
Figure 3. The Settings screen allows for test configuration based on user-specific requirements.
A customizable test report is generated that includes information such as test and lab details, appliance details, and test parameters. Manually-input comments are also visible on the report.
Figure 4. The Report Edit function allows for customizable test report details.
On the Condition and Measurement screen, users can start measurements, view trends, and review measurement data. Trend settings are configurable and allow users to select the trends they want to view, change colors, turn graticule and scale values off or on, and adjust the time per division.
Figure 5. The Condition and Measurement screen initiates the test and updates as the test is run.
Once testing is complete, a report is generated and ready to save on the output screen as a PDF, CSV, or both. For quicker and easier testing, the connection method and measurement settings can be saved and set to automatically load the next time the software is in use.
IEC62301 Test Report
Figure 6. Example test report.
Many devices that use standby power remain plugged in even when not in active use. Though these typically have a low power draw, with multiple devices plugged in year-round, a household or business is often consuming (and paying for) considerably more power than what they expect. To save both energy and money, standby power efficient devices, as defined by IEC62301 Ed2.0 (2011) and EN 50564:2011, must be used.
For design and test engineers to make accurate measurements that meet ENERGY STAR and EU Eco Directive mandates, Yokogawa Test&Measurement Power Consumption Measuring Software, combined with a WT series power analyzer (such as a WT300E), allows for easy setup, testing, and measurement of standby, test, and measure standby power in a variety of appliances. The ability to view trend data via custom-generated reporting means that verifying a device meets requirements is easier than ever.
Learn more about the Yokogawa Test&Measurement solutions and products mentioned in this app note:
With 0.02% accuracy and 1MHz bandwidth, the WT3000 delivers where the highest precision measurements are required. It is the industry standard for R&D work on inverters, motor drives, lighting systems and electronic ballasts, UPS systems, aircraft power, transformer testing, and other power conversion devices.
The WT1800 Power Analyzer offers maximum flexibility with up to six wattmeter elements, high bandwidths, simultaneous high speed digitizing, and wide voltage and current ranges. Although this model is still available, the newer WT1800E offers higher accuracy.
Yokogawa, the world's largest manufacturer of energy and power analyzers and meters, provides a broad choice of digital power analyzers to satisfy all requirements.