NEC 220.84 Transformer Sizing for Multiple Mulifamily Buildings

wowsk

New User
Location
Iowa
Occupation
Electrical Engineer
Hi,
I've used this forum often, but always someone else had asked my question. I signed up as I've got one that I haven't been able to find an answer for yet.

I have a project with a MV transformer feeding 5 multifamily buildings, each with 4 units. Following 220.84, for one building I get a connected load of 156kVA and a demand load of 70.2kVA.

When sizing the transformer for all 5 dwellings how do I determine the demand load? Is it 156kVA * 5 * 0.38 (demand factor for 20 units from Table 220.84) or is it 70.2kVA * 5?

In my mind the first option makes more sense because I am essentially looking at 20 units from the transformer perspective. It doesn't matter whether they are in different buildings or not.

Thanks for any and all advice.
 
Top