Before you begin
- A VoltMate account.
What the calculators cover
- Three-Phase Load & Balance, Circuit Load, Ohm's Law and a General Calculator for everyday electrical arithmetic.
- Voltage Drop and Cable Size Assistant for preliminary cable checks from length, load and cable data.
- Maximum Demand for connected load and preliminary maximum demand.
- Protective Device Helper, Earth Fault Loop and RCD Selection to compare device and protection considerations.
- EV Charger Assistant, Solar PV Assistant and Battery Storage to review supply, load, earthing and connection inputs for that work.
Use a calculator
- 1
Open Calculators and choose the tool.
- 2
Choose the supply type where asked, for example single-phase or three-phase.
- 3
Enter your values in the units shown. Where a tool asks for cable or device data, take it from the manufacturer's data or the current edition of the standard you work to.
- 4
Read the result together with the assumptions and warnings shown beside it.
- 5
Record the verified design values in your own design or certificate records.
What a result means
Results are preliminary checks from the values you enter. They are not a design approval or a compliance certificate, and they do not replace verification against the current regulations, the manufacturer's data and testing on site.
The competent person remains responsible for the design and for every value recorded on a certificate.
Common mistakes
- Entering a phase-to-neutral voltage where the tool asks for line-to-line voltage, or the reverse.
- Multiplying a single-phase mV/A/m value by √3 for a three-phase circuit. Voltage Drop takes the cable's single-phase value and converts it for you (× √3/2), then compares the drop between lines with the line voltage, 400 V by default.
- Using cable data from the wrong reference method or the wrong table.
- Treating an assistant's checklist as a finished design.
Troubleshooting
If a result does not appear, check that every required value is filled in and uses a full stop for decimals. If a result looks wrong, check the units first.