2365 L3 Unit 305 task B design current!?

[Papalazerus]

Q3 requires me to determine the design current for all of my final circuits.I'm happy with most of them except for the ring mains.
How do I work out the design current of a ring main?
The only things I can find are table H2.1 and table 7.1 in the on site guide but nothing that references an actual design current.

any help would be appreciated

 

[telectrix]

it's not possible to determine an actual design current for a socket circuit, as you cannot know what will be plugged in. all you can do is to stipulate a value so that Ib<In<Iz is satisfied.

 

[Papalazerus]

thanks for your reply.

what if all values were equal. for example my Ib is 32A and I use a 32A breaker and after all my factors are calculated the It comes out at 32A is that acceptable?

 

[happysteve]

For 13A socket circuits, your design current (Ib) is the same as your nominal protective device rating (In). The question asks for Ib for each circuit - there is no need to determine It for this question (though you do for one of the lighting circuits in a later question). But your thinking about It is correct.

 

[Papalazerus]

Thanks for your response guys, it's cleared things up for me. I've been struggling to get my head around the design module.

 

[telectrix]

just toput record straight, it's a ring final circuit, not a ring main.