Rating factor within an enclosure?

[lurch]

I seem to recall there is a rating factor that can be used within an enclosure effectively uprating the current capacity of the cable. Does any one know what this is and can it be found in BS7671 or is this a rule of thumb (?) for switchboard manufacturers?

 

[westward10]

Generally, yes if they are the same construction and csa.

 

[Bobster]

Rob. Agreed with regards to the safety margins, and in a lot of cases well over the top.

Off at a tangent a little. . . but still on current carrying capacity. If one doubles up on two cables would this simply double the current carrying capacity ?

If you're using normal cable calculations then yes effectively.

Delve a little deeper into it and then no, there will be a difference. Nothing to worry about at the level we work at.

However 2 x 70mm wires will take more than 1 x 140mm wire.

 

[lurch]

If you're using normal cable calculations then yes effectively.

Delve a little deeper into it and then no, there will be a difference. Nothing to worry about at the level we work at.

However 2 x 70mm wires will take more than 1 x 140mm wire.

that was my understanding also. But lets keepit simple !!!!!!!