What size cable do I need for my electrical wiring?

If you’re looking to work out the correct size of your cable according to AS/NZS 3008.1.1 requirements, our cable sizing calculator below can be used as a guide:

Clarification of Input Parameters:

Supply Voltage (V) - By default, this refers to the supply voltage, which stands at 230 V for a single-phase supply and 400 V for a three-phase supply.

Phase Selection - Choose the phase configuration, which can be single-phase, three-phase, two-phase, or DC.

Load Specification - State the load's measurement, which could be in Amps, kilowatts, kVA, or horsepower. For a three-phase load, input the highest loaded phase's current.

Maximal Voltage Drop (%) - The cable sizing will be automated to satisfy the maximal voltage drop requirement. A common guideline isa maximum voltage drop of 5% for the total electrical system, and a maximum of 3% for any individual circuit branch. This is to ensure that all devices connected to the circuit receive adequate voltage to operate correctly. However, the actual acceptable voltage drop can vary based on specific circumstances, including the nature of the load (for example, some sensitive electronics may require a smaller voltage drop), and how critical the operation of the device is.

Power Factor - Record the load's power factor (assumed to be lagging). This calculator's voltage drop computation is more precise due to considering the power factor.

Cable Length (m) - This refers to the cable's length stretching from the supply point to the load.

Cores - Indicate whether the cable type will be single-core or multicore (2 core or 3/4 core based on the phase selection).

Insulation - Choose the insulation type that impacts the highest permissible operating temperature, hence influencing the current rating. Cables with a higher permissible temperature (dependent on the insulation type) will possess a higher current rating.

Installation - Select the cable circuit's installation method that corresponds to your installation. If the installation method varies along its route, opt for the most challenging situation (resulting in the lowest possible current rating) throughout its entire length. Refer additional information provided under calculator on this page

Decoding Results:

The smallest active cable size that satisfies both the current-carrying capacity and maximum voltage drop requirements is provided. Remember, a cable size larger than this minimum is also acceptable and could be more cost-effective in terms of electrical losses over its lifespan.

The table number utilised from Standard AS/NZS 3008.1.1:2017 is given along with the result, facilitating your cross-checking and reference of the results.

Disclaimer- Our engineering calculators only provide guidance and estimate to help you determine your component size requirements. This guide should not be considered a replacement for an expert advice. If you have any questions regarding TPCE calculators, please feel free to CONTACT US today, one of our friendly experts will be in touch with you as soon as possible to assist you with your engineering needs.