Design project pool/café

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Diani1

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hi all

i am currently studying, so please bare with me...

i am trying to do some cable calculations and could use a little nudge in the right direction.

I have a café kitchen, I need to work out cable calculations for some sockets. there is no spec as to what appliances will be plugged in, so i assumed 90% (diversity) of 32A(28.8A). as a kitchen may use various high wattage equipment (tea urns, toasters etc)
the cables have to be enclosed in conduit, 70c single core thermoplastic insulated cables. (35c) Ca 0.94 Table 4B1. Grouped with 3 other circuits (0.7Cg table 4C1)
It=In/Ca x Cg
It = 32/0.94 x 0.7 48.63A which is very high. I was thinking to make this a ring circuit as doubling the resistance would halve the amps right? but you cant put 5mm in the cable size box and table 4D1A only gives maximum amps for 2.5mm and 4mm which both max amps are lower than what I have 48.63A and even when halved 24.32A this is still higher on table 4D1A for 2.5mm and there is no way i would do a 4mm ring as i imagine that would be near impossible.

upon reading this again I think i will just split the circuit to 2x20A radials to make my life easier but any advise you wish to give on this I would be very grateful.

(please don't tell me to call a spark because this is for studying, not a real job. I just need advise so please don't give me rude or harsh negative feed back)

thanks
 
You have not been given any indication of Appliances?
What is the spec for the kitchen? How is the hot water supplied?
You have been told that cables will be grouped with 3 other circuits? Do we know what these circuits are?
 
You have not been given any indication of Appliances?
What is the spec for the kitchen? How is the hot water supplied?
You have been told that cables will be grouped with 3 other circuits? Do we know what these circuits are?
No,not in regards to the sockets. Everything else has its own circuit (fridges,dishwasher etc) I haven't been told this, I grouped them with the two fridge circuits.
Actually thinking about it, I don't think I would get 9 2.5mm cables in a 25mm pvc conduit so this will reduce the amps. I will check this tomorrow
Thanks for the reply 👍
 
If you are using conduit/trunking you don't want to be using cables but single insulated conductors.
 
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