Re: Multi family optional calculations
Take care that you do not "double dip" into the demand factor pool. The simple way to say this is that when you look at any single wire, you first add up the load that is downstream of that wire, then you use the demand factor that applies to the number of units that are included in that load.
I presume you are in 220.84, "Multifamily Dwelling." When you look at the feeder to a single apartment, there is only one unit downstream of that feeder, and you have no demand factors available. When you look at the feeder to a meter center, you add up the load on the 22 units, and apply the demand factor of 36%.
Now look at the service to the set of 5 meter centers. You have to add up the loads on all 110 units, without using the results of the previous step. You do not get to take the 36% demand factor (from each meter center), and then apply another demand factor 45% for 5 meter centers) to that sum. That would be "double-dipping." Rather, you add all the loads on 110 units, without using any demand factor in obtaining that sum. When you get that sum, you then apply a demand factor of 23% (for having more than 62 units).