Trunking size calculations & clips

[bsr]

Hi, I want to put 3 cables in a piece of trunking and have two questions.

1. I am well under the conduit capacity (using a NAPIT table). Do I need need to derate cable due to grouping or can I stick with method B capacities?

2. If I got some biggish trunking eg 75x25 is there a way to separate the cables and would that help? Eg using cable ties to separate the cables as you would do on cable trays?

I have 3x 6mm T&E on B32 and B40.

Thanks

 

[EFLImpudence]

There is probably no need for further derating in a domestic installation but, just in case, what are the circuits supplying?

 

[bsr]

Thanks. A shed, a hot tub, and a solar generator. In reality the solar is capped at 20A, the hot tub is 15A, and the shed rarely has more than say 10A for a saw or grinder (and intermittent at that).

In reality I have no concerns but want to keep code compliance if possible.

 

[EFLImpudence]

That all looks fine, then; will hardly get warm.

As I said, grouping is rarely a concern in domestic installations