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Calculate in your browser. Downloading a PDF report sends your project to AutoRef for report generation.
Power quality
Draw a low-voltage network as a single-line diagram, add six-pulse VSDs and loads, and see THDi, TDD and THDv update as you edit. Compare indicative results with IEEE 519 reference limits, explore utility and generator supply, and download a PDF calculation report.
Six-pulse VSDs · IEEE 519 reference limits · Generalised summation · Single-line diagram
Thermal design
PreviewCalculate switchboard temperature rise using IEC TR 60890:2022. Draw enclosure tiers, enter heat losses in watts, place natural ventilation openings and horizontal partitions, and compare informative fan cooling estimates.
IEC TR 60890:2022 natural temperature rise · informative fan estimates based on Annex K
Shared board depth · Tier watt losses · Ventilation · Fan comparison
Use the free harmonic calculator to model a low-voltage network with six-pulse variable speed drives and linear loads. Explore current distortion (THDi), voltage distortion (THDv), harmonic spectra and illustrative waveforms as you edit the single-line diagram.
THDi describes current distortion relative to the fundamental current. TDD uses the maximum demand load current at the point of common coupling (PCC), so enter that demand value to assess the current reference limits. Review the PCC results against IEEE 519 reference limits, or explore incremental THDv for a generator supply.
The calculator uses approximate drive and network models. Its IEEE 519 checks are references, not a complete compliance assessment or a substitute for measurements and engineering verification. Save your project, review the spectra and waveforms, and download an AutoRef Suite PDF calculation report.
The free IEC 60890 temperature rise calculator estimates internal air temperatures in low-voltage switchgear and controlgear enclosures. Enter the ambient temperature, tier dimensions and total power loss, then review the temperature profile for each tier.
Model enclosure heat dissipation with effective cooling surface areas, covered faces, ventilation openings and horizontal partitions. For a tier with a fan, compare delivered airflow in cubic metres per hour against estimated temperature. Fan cooling uses an informative heat-balance estimate based on Annex K of IEC TR 60890:2022.
IEC TR 60890 provides a method for calculating enclosure air temperature rise. If you are assessing a switchboard under AS/NZS 61439, check the applicable edition, calculation conditions and design-verification requirements. This tool is informative only: it does not verify all AS/NZS 61439 requirements or certify an assembly. Users are responsible for independently verifying inputs, assumptions and results.
Prepare the enclosure dimensions, installation and exposed-surface details, ambient temperature, and total watt losses for each tier. For natural ventilation, use the vent manufacturer's unobstructed free area. For fan cooling, use delivered airflow appropriate to the installation. Review the tier results and download an AutoRef Suite PDF report with the arrangement, assumptions and temperature curves.
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