The following table lists the recommended minimum sizes of earthing conductors.
Note: This serves only as a guide, calculations are still required for verification.
| Nominal size of active conductor mm² | Nominal size of copper earthing conductor | |
| mm² | ||
| With copper active conductors | With aluminium active conductors | |
| 1 | 1* | - |
| 1.5 | 1.5* | - |
| 2.5 | 2.5 | - |
| 4 | 2.5 | - |
| 6 | 2.5 | - |
| 10 | 4 | - |
| 16 | 6 | 4 |
| 25 | 6 | 6 |
| 35 | 10 | 6 |
| 50 | 16 | 10 |
| 70 | 25 | 10 |
| 95 | 25 | 16 |
| 120 | 35 | 25 |
| 150 | 50 | 25 |
| 185 | 70 | 35 |
| 240 | 95 | 50 |
| 300 | 120 | 70 |
| 400 | ≥120† | ≥95† |
| 500 | ≥120† | ≥95† |
| 630 | ≥120† | ≥120† |
* - May be used only when incorporated in a multicore cable
† - A larger conductor may be required.
Source: AS/NZ 3000-2007, Table 5.1
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Can you please mention the source(Standard) behind this Table.
If not a Standard, might be calculations.Can you please share it.
Thanks & Regards
Hi, Shams-ul-Hassan,
I have added the source as requested. Thank you for visiting my blog.