300 mm² metric wire specifications (IEC 60228): 19.544 mm diameter, 367A ampacity (copper, IEC 60364-5-52 method A1, PVC, 2 loaded), closest equivalent is 600 kcmil. Resistance, weight, and common uses.
| Cross-sectional area | 300 mm² |
| Diameter (solid equivalent) | 19.544 mm |
| Closest AWG equivalent | 600 kcmil (304 mm²); larger than 4/0 AWG |
| Ampacity (copper, IEC 60364-5-52 method A1, PVC, 2 loaded) | 367 A |
| Ampacity (aluminum) | 289 A |
| Max resistance (copper, 20°C, IEC 60228 class 2) | 0.0601 Ω/km |
| Max resistance (aluminium, 20°C, IEC 60228) | 0.1 Ω/km |
| Weight (copper) | 2688.0 kg/km |
| Weight (aluminum) | 810.0 kg/km |
The IEC 60228 metric system specifies wire by cross-sectional area in mm², while AWG uses a gauge number system. The closest North American equivalent to 300 mm² is 600 kcmil, but they are not exactly the same size.
Metric sizes are standard in Europe, Asia, Australia, and most countries outside North America. When replacing or matching wire between systems, always verify the actual cross-sectional area rather than relying on approximate equivalents.
300 mm² metric wire (IEC 60228) is rated 367A (copper, IEC 60364-5-52 method A1, PVC, 2 loaded) and is commonly used for utility power distribution, high-capacity industrial feeders, power plant connections. Its diameter is 19.54 mm. The closest AWG equivalent is 600 kcmil.
300 mm² wire is approximately equivalent to 600 kcmil in the American Wire Gauge system. Note that IEC and AWG sizes do not align exactly — when substituting, choose the AWG size with equal or greater cross-sectional area to ensure adequate ampacity.