Copper vs aluminium conductors in Australian cables
How copper and aluminium cable candidates differ for voltage drop, loss, cost, termination and installation review.
What The Material Changes
Copper and aluminium are not interchangeable labels on the same metric cable size. The conductor material changes resistance, voltage drop, cable loss, weight, termination details, available products and cost assumptions.
In Australian cable schedules, the same 35 mm2 size label can point to different electrical and mechanical behaviour depending on whether the cable is copper or aluminium, and depending on the actual cable construction and product data.
Electrical Comparison Points
Voltage-drop and loss comparisons need material-specific resistance data, usually entered as ohm/km or as a cable data value sourced from the project, manufacturer or reviewed document. A copper resistance value must not be reused for an aluminium candidate.
For a simple entered-resistance comparison, AUWiring calculates voltage drop, percent drop, cable loss and material cost from the values entered by the user. That makes the trade-off visible, but it does not make the material choice.
| Field | Copper candidate | Aluminium candidate |
|---|---|---|
| Resistance | Enter copper resistance or voltage-drop data for the actual cable. | Enter aluminium resistance or voltage-drop data for the actual cable. |
| Voltage drop | Often lower for the same nominal size when source data confirms it. | Often higher for the same nominal size, so it needs its own data. |
| Cable loss | Calculated from current and voltage drop. | Calculated separately from aluminium data. |
| Material cost | Enter project or supplier cost per metre. | Enter project or supplier cost per metre. |
| Termination | Product-compatible lugs and instructions still apply. | Lug, jointing and compatibility checks usually need explicit attention. |
Worked 80 A Comparison
Consider two entered candidates for a 70 m run carrying 80 A on a 400 V basis. The copper candidate uses 0.727 ohm/km. The aluminium candidate uses 1.15 ohm/km. In a simplified two-conductor comparison:
- Copper voltage drop is about 8.14 V, or 2.04% of 400 V.
- Aluminium voltage drop is about 12.88 V, or 3.22% of 400 V.
- Cable loss is about 651 W for the copper candidate and 1030 W for the aluminium candidate.
- At AUD 11.00/m for copper and AUD 7.50/m for aluminium, the entered material cost is AUD 770 versus AUD 525.
That example shows the trade-off. It does not settle current-carrying capacity, termination, mechanical suitability, route space or installation method.
| Field | 35 mm2 copper candidate | 35 mm2 aluminium candidate |
|---|---|---|
| Material input | Copper data set. | Aluminium data set. |
| Voltage-drop basis | Copper resistance or voltage-drop data for the chosen cable construction. | Aluminium resistance or voltage-drop data for the chosen cable construction. |
| Termination note | Product-compatible lugs and instructions still apply. | Lugs, jointing method and compatibility need explicit checking. |
| Review outcome | Not interchangeable with aluminium simply because the size label matches. | Not interchangeable with copper simply because the size label matches. |
Mechanical And Installation Questions
Electrical arithmetic is only one part of the comparison. Aluminium can change route weight, bending, termination hardware, corrosion controls, enclosure space and product availability. Copper can change cost, weight and installation handling. Both materials still need product data and project requirements.
Keep conductor material beside cable size, current, route length, voltage basis, resistance source, lug or termination note and installation method. If material-specific data is missing, stop the comparison rather than borrowing values from another cable.
Next checks
- Use the copper aluminium comparison calculator when both material candidates have their own resistance, route, current and cost values.
- Use the voltage-drop calculator when only one cable run is being checked against a project target.
- Use the cable-size workflow before carrying either material into current-carrying capacity, derating or protection review.
Boundaries
- This page does not choose conductor material or cable size.
- It does not provide current-carrying capacity values, supplier prices or termination instructions.
- Manufacturer data, lugs and terminals, corrosion controls, route conditions, project documents and competent review remain controlling inputs.
Copper vs aluminium conductors in Australian cables in Australian work
Explain copper and aluminium conductor differences so cable-size, voltage-drop and comparison checks use material-specific data. The useful record is not just the final number or definition; it is the combination of the entered value, the supply arrangement, the equipment or circuit reference and the decision that still needs project review.
Help users understand copper and aluminium conductor differences in Australian cable work before comparing current, voltage drop, loss, termination and cost. Keep the wording in Australian English, use metric units, and treat 230/400 V a.c. at 50 Hz as the ordinary low-voltage context unless the project information states a different value.
Checks that belong beside this page
- Regional scopeAustralia; public cable conductor terminology.
- Standards contextAS/NZS 3008 context; current project installation conditions, licensed data and product requirements remain controlling sources.
- Review timingReview cadence: Annual conductor wording review or sooner if cable calculator or guide wording changes.. Update trigger: Update when cable-size calculator material fields, metric size table rows or conductor guide wording changes.
Practical use sequence
For Copper vs aluminium conductors in Australian cables, begin with the circuit, board, load, cable route, equipment item or measurement record named by this topic. Record the value basis, such as current, voltage, kW, kVA, route length, test value, product rating, tariff value or worksheet field, then note the review boundary so another person can see what this page explained and what still needs a project decision.
The strongest Copper vs aluminium conductors in Australian cables record is specific enough to be reviewed later. It names the Australian context, keeps the entered assumptions visible, separates calculation support from compliance decisions and shows where a calculator, table, chart or term definition should be opened next.
Record detail to capture
Keep the Copper vs aluminium conductors in Australian cables note attached to Australia; public cable conductor terminology.. When the page is used during design, estimating, testing, review or study work, write the entered assumption, the source that supplied it, the circuit or equipment label and the person or role that must review the following action.
For Copper vs aluminium conductors in Australian cables, the review cadence is Annual conductor wording review or sooner if cable calculator or guide wording changes. and the update trigger is Update when cable-size calculator material fields, metric size table rows or conductor guide wording changes.. If the topic connects to Metric cable sizes, open that page after the current definition, input basis or boundary has been recorded, so the next calculation inherits the right Australian context.
A complete Copper vs aluminium conductors in Australian cables record leaves four facts visible: why the page was opened, which Australian supply or equipment context applies, which value remains user-entered and what later change would alter the result. That makes the page useful as a working note instead of a loose reference copied away from the project evidence.
- InputsWrite down the entered values and their units before comparing results across calculators or reference pages.
- LocationKeep the value tied to the board, circuit, cable run, equipment terminal, supply point or worksheet row it describes.
- Authority checkCompare the record with current Australian requirements, DNSP or local authority conditions and product information.
- Review trailRetain the date, edition context and reason for the calculation so later changes can be traced.
Connected AUWiring pages
Use the related pages for Copper vs aluminium conductors in Australian cables when the topic needs a calculator input, lookup table, formula chart or supporting term before the project record is complete. Open Metric cable sizes first when that page owns the next value or definition.
- Metric cable sizesMetric conductor labels for cable worksheets.
- Voltage-drop formulasFormula relationships affected by conductor data.
- Cable sizeReview candidate cable data from entered project values.
- Voltage dropReview voltage-drop values from entered conductor data.