Australia [exclusive] — Cable Size Chart

In the Australian electrical industry, guessing is not a luxury—it’s a fire hazard. Whether you are wiring a shed in rural Queensland or installing LED downlights in a Melbourne apartment, the phrase “that looks thick enough” doesn’t hold up against the law.

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| Conductor Size (mm²) | Current Rating (Single phase, clipped direct) | Max Run Length (10A load, 5% drop) | Typical Use | |----------------------|------------------------------------------------|-------------------------------------|--------------| | 1.5 mm² | 15 Amps | 30 metres | Lighting | | 2.5 mm² | 20 Amps | 18 metres | GPOs (10A) | | 4.0 mm² | 32 Amps | 29 metres | 15A/20A loads| | 6.0 mm² | 40 Amps | 43 metres | 32A ovens | | 10 mm² | 55 Amps | 72 metres | Sub-mains | cable size chart australia

Enter the . More than just a table of numbers, this tool is the backbone of safe, compliant electrical work under AS/NZS 3008 (Electrical Installations – Selection of cables). For Australian electricians, reading this chart correctly is the difference between a circuit that runs cool and one that melts into the insulation. In the Australian electrical industry, guessing is not

Always refer to the latest for copper cables, and when in doubt, go up a size. The 6.0mm² you install today is a problem you will never have tomorrow. Disclaimer: This feature is for informational purposes only. All electrical work in Australia must be performed by a licensed electrician who will calculate cable sizes based on site-specific conditions and current regulations. More than just a table of numbers, this

Note: These ratings drop significantly in ceiling insulation (derating factor ~0.5 to 0.88). 1. The Ambient Temperature Adjustment The standard cable chart assumes 30°C or 40°C ambient. In a black-tiled roof in Western Australia in January, temperatures hit 70°C+. When you derate a 2.5mm² cable (rated 20A) by 0.50 for a hot, insulated ceiling, its safe capacity drops to 10 Amps . Suddenly, a vacuum cleaner tripping the breaker makes sense. 2. Voltage Drop (The 5% Rule) AS/NZS 3000 mandates that voltage drop from the point of supply to the equipment does not exceed 5% (or 3% for lighting). Australia’s sprawling suburban blocks mean long cable runs. A 2.5mm² cable carrying 10A over 60 metres will fail voltage drop long before it fails current rating. The chart must be read left (amps) and right (distance). 3. The V-90 vs. V-75 Standard Modern Australian charts use V-90 insulation (rated to 90°C). If you have older V-75 cable, you must use a different column. Mixing them up is a common compliance error. How to Read the Chart Like a Pro Scenario: You are installing a 15A air conditioner. The run is 45 metres through a roof space filled with thermal insulation.