Enter your load current and cable run length to find the minimum cable size. Voltage drop is checked simultaneously against the AS/NZS 3000 5% limit.
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Under AS/NZS 3000, select a cable whose current-carrying capacity meets or exceeds the circuit load, then verify voltage drop does not exceed 5%. Derating factors apply when cables are bunched or in conduit.
AS/NZS 3000 recommends a maximum of 5% from the point of supply to any final sub-circuit outlet. For long runs, keeping it under 3% is best practice to allow for future load growth.
2.5 mm² TPS is most common at typical run lengths. For runs over 30–40 m, step up to 4 mm² to stay within the 5% voltage drop limit. Always check the actual run length and installation method.
Yes. Select 230V for single-phase circuits or 400V for three-phase. The calculator also covers 12V and 24V DC circuits for low-voltage applications.
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