Cable Size Calculator
South West Tech — AS/NZS 3008.1.1:2025 · AC & DC · Cu & Al · conduit sizing
INTERNAL USE ONLY — VERIFY AGAINST THE STANDARD— mm²
| Table rating (before corrections) | — |
| Correction factors applied | — |
| Derated capacity | — |
| Voltage drop at load | — |
| Size needed for current alone | — |
| Size needed for voltage drop alone | — |
| Heavy-duty rigid conduit (—) | — |
| Minimum earth conductor (Cu, AS/NZS 3000 Table 5.1) | — |
Internal SWT tool — AS/NZS 3008.1.1:2025. AC ratings Tables 3.9–3.20 (Cu & Al), DC Tables 3.21–3.22 (Cu); CFs Tables 3.33, 3.44–3.48; voltage drop from three-phase Vc mV/A·m at conductor operating temperature (×1.155 for 1φ) and Table 4.6(A) d.c. resistance for DC. 110°C cables: enclosed ratings assume METALLIC conduit; not recommended in non-metallic conduit. Conduit sizing from the Electra Cables 'Cables in Conduit' chart (SM240725, heavy-duty rigid, AUS sizes) — indicative only; confirm against AS/NZS 3000 App C for other cable brands. Assumes single circuit underground. Earth size is the AS/NZS 3000:2018 Table 5.1 minimum: * = only within a multicore cable or flexible cord; † = a larger earth may be required by Clause 5.3.3.1.1 — and long runs may need a larger earth for fault-loop impedance. Check short-circuit withstand and protection coordination separately. DC values transcribed from NECA MKB — spot-check critical jobs.