Design course max demand question

[YoungBart]

Hi all, I appreciate this has probably being posted time and time again, but I'm using my phone and the search threads button isn't working.
Basically I'm just starting my design course (2396) project and I'm on with working out the max demand and diversity, basically I've split the job up and have got about 10 32A ring circuits, my understanding that the diversity calc for that is; highest breaker (32A) plus 40% of the rest meaning I end up with about 150A which seems hell of a lot.
am I missing the trick here? Or is it just actually that high?
Thanks
James

 

[alanl]

You need to know what the building is used for, what equipment they are likely to use, and when it will be used.

Then find out what wattage the equipment uses, add it up, and see what the total is. If an office environment, then everything is likely to be on for 9 hours a day, so no diversity allowed - that doesnt mean you put down 32amps for your RFC, just the total wattage that is likely to be used all day.

Other circuits,such as canteen socket outlets, may be given some diversity, it is up to you to decide.

 

[Brighton sparky]

Have a look at guidance note 1 table H2,it might help you. I think the 40% bit is for domestic it's even higher for shops and offices etc but sounds right to me

 

[Brighton sparky]

Also it's 100% of the highest rated appliance on the circuit so not necessarily 32A

 

[YoungBart]

Thanks for the replies, I've been going off the table in the OSG 1A and 1B etc. Most of the sockets are in classrooms, and judging by their positioning and frequency I'd assume they are for computers, so In theory I could assume a load of 2A per double socket? And then forget about the factors applied in the tables?