For a 10kA fault, 1s clearing time, 95mm² Cu easily withstands the temperature rise.
Disclaimer: This post is for educational guidance. Always refer to the current AS/NZS 3008 standard and engage a qualified electrical engineer for final design decisions. cable sizing calculator as3008
If you work in electrical design or installation anywhere in Australia or New Zealand, you know that AS/NZS 3008 is the bible for cable sizing. But let’s be honest—manually applying derating factors for temperature, soil thermal resistivity, grouping, and AC resistance can turn a simple job into a headache. For a 10kA fault, 1s clearing time, 95mm²
Whether you choose a free online tool, a custom spreadsheet, or commercial software, make sure it’s based on the (currently 2017 with 2019 amendments). Standards update—your tools should too. If you work in electrical design or installation
Select cable type, insulation, and installation method (buried – Table 4 or 5). Base current for 70mm² Cu XLPE is around 235A.
At 200A, 100m run, 95mm² Cu gives ~0.45 mV/A/m × 200A × 100m / 1000 = 9V drop (2.2% of 415V). Well within 5% limit.
