2365 Design Drawing Breaker Sizing

Deckotah · Dec 14, 2022

Hi, I am finishing up my design drawing for submission. I am working out all my circuit calculations and am a bit confused about what size I should use for my circuits which are supplies for my additional Distribution Boards ( Hotel, Pool, Summerhouse etc ). My hotel DB however even when accounted for diversity is still coming in as 136A. Is this excessive for a single circuit or does it not really matter?

I only worry because on my main DB ( The one C & G give you the Ze for ) I am getting a total demand of around 358A

davesparks · Dec 14, 2022

Deckotah said:
My hotel DB however even when accounted for diversity is still coming in as 136A. Is this excessive for a single circuit or does it not really matter?

A single circuit could be hundreds or even thousands of amps of that is what the load requires.

In these design projects they are looking for you to do the calculations properly and come up with the answers, the scenarios they give you don't always reflect the real world.

136A seems pretty low demand for a whole hotel, but then what size hotel is it?

Deckotah · Dec 14, 2022

davesparks said:
A single circuit could be hundreds or even thousands of amps of that is what the load requires.

In these design projects they are looking for you to do the calculations properly and come up with the answers, the scenarios they give you don't always reflect the real world.

136A seems pretty low demand for a whole hotel, but then what size hotel is it?

Yeah that was my thoughts to be honest was just wanting clarification thank you.

I have a total maximum demand of 340.96 but then did a calculation for diversity for the rooms themselves so like even though it's a 20A radial the real usage is only going to be like a laptop, phone charging, hairdryer etc only using like 9.24A

I have added additional DBs other than the hotel because I kind of looked at the project as a real-world situation and put separate Submains in the Kitchen and Pool area (also to help with the suggested maximum circuit size of 30m). I think this should be fine as I have worked out the theoretical Zdbs using R1+R2? Is this going to be okay?