Copper vs aluminium cable selection
A guide to recording material assumptions when comparing copper and aluminium cable candidates in Australian electrical worksheets.
Why material choice needs a record
Copper and aluminium cable candidates can differ in current-carrying capacity, impedance, voltage drop, termination requirements, physical size, weight and cost. A calculator comparison is useful only when the reviewer records which values belong to which material.
The goal is a traceable comparison, not an automatic material decision.
Review workflow
- Identify the copper candidate and aluminium candidate separately.
- Record the source for current-carrying capacity for each candidate.
- Record the voltage-drop data that belongs to each candidate.
- Compare current margin, voltage-drop margin, route length and cost assumptions.
- Review termination, installation and manufacturer requirements before carrying a candidate forward.
Material comparison table
| Field | Copper candidate | Aluminium candidate |
|---|---|---|
| Metric label | Record exact mm2 label | Record exact mm2 label |
| Capacity source | Source value and basis | Source value and basis |
| Voltage-drop data | Candidate-specific data | Candidate-specific data |
| Termination context | Product and lug requirements | Product and lug requirements |
| Route impact | Length, installation and space | Length, installation and space |
| Cost record | Unit cost and waste assumption | Unit cost and waste assumption |
Reading comparison outcomes
A candidate with more current margin may still fail voltage-drop or installation review. A lower-cost candidate may still create termination, route-space or mechanical issues. Keep the calculator output as one comparison input.
When material-specific data is missing, stop the comparison. Do not borrow values from another material or cable family.
Boundaries
- Do not use a generic material rule without source data.
- Do not apply copper voltage-drop data to aluminium.
- Do not treat cost as the only selection criterion.
- Do not describe either candidate as compliant without full project review.