Voltage Rise
Calculate voltage rise for embedded generation or PV.
Questions
Each answer describes what this tool calculates. The result is a design aid. Verify against the current standard.
What does the voltage rise calculator do?
The tool works out the output current of the inverter from its rating, the voltage and the power factor. It then works out the rise along the cable to the point of supply, in volts and as a percent. It also reports the longest run that still meets the limit.
What voltage rise limit does the tool use?
The tool uses 2 percent as the default and you can change it. That figure is the assumption made by this tool, not one read from a standard. AS/NZS 3000:2018 Clause 3.6.2 Note 3 refers voltage rise to AS/NZS 4777.1, so check the current edition of that Standard for the limit and clause that apply.
Which inputs matter most?
The inverter rating and the run length scale the rise directly. The conductor size and material set the resistance. The power factor is limited to the range 0.8 to 1 and defaults to 1, which is the usual inverter case. Cables in parallel divide the impedance.
What else should I check?
This tool covers the rise on the inverter cable only. It does not cover the supply network, protection or anti islanding. Use the cable size tool for the current rating of the same cable. The inputs sit in the page address, so a link reproduces the calculation.