I would need a letter from an engineer before they would even consider letting me use clause 5, so it isn't like just anyone can cherry pick the loads.
You have an existing kitchen so you should be able to look at their power bills to get the demand for the previous year. (75 kva plus 15 kw is 90 kva, not 112.5 kva) I assume you aren't looking at clause 8 for a reason. Is that reason, because 90 amp overcurrent x 600 volts x 1.732 = 93.5 kw?
Maybe you want to reconsider what "special loads" you are adding to your calculation under 8-210.
Could any of the new equipment be changed to 600 volts to avoid the transformer?
How about adding a new 15 kva xfrmr and a new panel for the new loads?
I should mention that almost every piece of existing equipment in this space is being relocated and therefore a new branch circuit will be required. This is why I am paying so much attention to the existing load and not looking too closely at clause 8-106(8). Summing up the NEC demand loads of all of the existing and new equipment that we are adding gives us 93KW. We know that we are adding roughly 15KW demand load in new equipment alone. So 93KW - 15KW = 78KW in existing demand load which means we are technically overloading the nameplate rating of the 75KVA transformer per NEC calculations. So if we were to use NEC demand for this restaurant, we would consider replacing the existing 75KVA transformer with the next largest standard transformer size - 112.5KVA (or just adding a new 45KVA transformer). Since it appears that CEC requires connected loads to size services and feeders, we would need to size our transformer based on the sum of all of the existing and new equipment - a total that gives us 135.4KW. Therefore I would think we need to replace the existing 75KVA transformer with a 150KVA transformer (or add a second 75KVA transformer.)
We know that a transformer or service upgrade is in our future, the issue is trying to determine if we need a transformer system that can cover the CEC connected load of 135.4KW or a transformer system that can cover the NEC demand load of 93KW.
I don't think there's much we can put ahead of the transformer on the 600V wireway.
twh, I appreciate this dialogue and your insights - it is helping me get a clearer grasp of the CEC.
