Hi Reader

I am just letting you know.

I have changed how aluminium earth cables are calculated in the Cable Size Calculator.

1. Minimum aluminium earth sizes

I revised the earth size selection from IEC 60364-5-54 (Table 54.2) to sizes that I calculated based on AS/NZS 3000 (Table 5.1).

I originally used the IEC table because AS/NZS 3000 specifies only copper earth sizes. It does not include aluminium earth sizes.

The benefit of this change is that some of the new sizes are smaller than those recommended by the IEC. This adjustment was made following a user query.

For this update, I calculated the equivalent aluminium earth sizes based on the recommended copper earth sizes in AS/NZS 3000 Table 5.1. The calculations were based on impedance and fault rating, rather than the current rating.

For more background information and detailed calculations please refer to my article, "Minimum Cable Copper Earth Sizes From AS/NZS 3000 - With Calculated Aluminium Earth Sizes."​

2. Auto earth size for aluminium multi-core cables

For multi-core aluminium cables, in Auto mode, the calculator will select an earth size equal to the active size. This change was made because, in most commercial aluminium cables the earth size is the same as the active size.

However, if the cable you intend to use has a different earth size, you can manually adjust it in the calculator.

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I hope these changes are useful. Please let me know if you have any questions or suggestions. I appreciate your feedback.

Adam van Staden
​LinkedIn Profile​
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This information does not constitute legal, professional or commercial advice. JCalc Pty Ltd gives no guarantees, undertakings or warranties in this regard, and does not accept any legal liability or responsibility for the content or the accuracy of the information so provided, or, for any loss or damage caused arising directly or indirectly in connection with reliance on the use of such information.