derating multiple trefoils

I have just posted a follow up query on use of quads and derating thereof

I largely agree with the comments above (I think you missed Jaymack's point that you'll need to consider longitudinal spacing of cleats along each cable/trefoil to design out bursting due to magnetic effects of through fault currents).

I would suggest, as Mike did above, that you get a copy of ERA* report 69-30 parts III and V, which might have more appropriate arrangements for what you're trying to achieve. It's often my go to for these situations.

*Now RINA of course

You will also need to consider asymmetric loading due to the magnetic fields.

If the cables are installed outside and exposed to the Sun, for a continuous load I would advise you to consider the heating effect of insolation and/or radiation from hot surfaces (e.g. reflection from a concrete floor). Or to shade the cables.

However, for a project such as you suggest, with multiple large supplies and presumably a substantial budget, I might be inclined to go for a detailed calculation per IEC 60287. In practice that means specialist software (or a consultant that has it), and you do need to understand what you're doing, but it frees you from the by-necessity generic tables and you can see exactly what's going on.

I largely agree with the comments above (I think you missed Jaymack's point that you'll need to consider longitudinal spacing of cleats along each cable/trefoil to design out bursting due to magnetic effects of through fault currents).

I would suggest, as Mike did above, that you get a copy of ERA* report 69-30 parts III and V, which might have more appropriate arrangements for what you're trying to achieve. It's often my go to for these situations.

*Now RINA of course

You will also need to consider asymmetric loading due to the magnetic fields.

If the cables are installed outside and exposed to the Sun, for a continuous load I would advise you to consider the heating effect of insolation and/or radiation from hot surfaces (e.g. reflection from a concrete floor). Or to shade the cables.

However, for a project such as you suggest, with multiple large supplies and presumably a substantial budget, I might be inclined to go for a detailed calculation per IEC 60287. In practice that means specialist software (or a consultant that has it), and you do need to understand what you're doing, but it frees you from the by-necessity generic tables and you can see exactly what's going on.

Thanks Jam, I shall look at the references....