I am looking for some insight on how to interpret 220.16 regarding dwelling units.
Supposing we have a house that has an unfinished basement. Initially, the load calculation for the home would have to consider the unfinished area as "floor area" since it is "adaptable for future use" (220.5(C)). 220.41 would apply 3VA/ft to this value, then we would complete a standard general lighting calculation. Suppose also in this example that we are only finishing the area as living areas and bedrooms with no additional specific appliance loads.
My first question: 220.16 specifically details dwelling units, and says to use 220.14 to calculate the branch circuit loads when adding to an existing installation. Notice that 220.14(I) begins with "except as covered in 220.41". I'm taking that to mean that 220.14(I) (180VA per receptacle + the lighting load) would not apply in this case since the square footage GL calculation already considered general use lighting and receptacles for that unfinished area (at the time). Simply put, the example would NOT require an increase in the load calculation since it was already considered in the first place. (With the caveat that it would be appropriate to run the calculation again for the whole house to verify). Is this accurate?
My second question: It seems 220.16 is saying we must add the load to the existing load calculation rather than recalculating and applying demand factors. Suppose in another instance, we add a new fastened-in-place appliance. If the house already has 4 or more, does this mean I cannot apply the 75% demand factor per 220.53? 220.16 seems to simply say I must use 220.14(A) and simply add the specific appliance load to the calculation. But the two scenarios give separate results. Which is it?
Supposing we have a house that has an unfinished basement. Initially, the load calculation for the home would have to consider the unfinished area as "floor area" since it is "adaptable for future use" (220.5(C)). 220.41 would apply 3VA/ft to this value, then we would complete a standard general lighting calculation. Suppose also in this example that we are only finishing the area as living areas and bedrooms with no additional specific appliance loads.
My first question: 220.16 specifically details dwelling units, and says to use 220.14 to calculate the branch circuit loads when adding to an existing installation. Notice that 220.14(I) begins with "except as covered in 220.41". I'm taking that to mean that 220.14(I) (180VA per receptacle + the lighting load) would not apply in this case since the square footage GL calculation already considered general use lighting and receptacles for that unfinished area (at the time). Simply put, the example would NOT require an increase in the load calculation since it was already considered in the first place. (With the caveat that it would be appropriate to run the calculation again for the whole house to verify). Is this accurate?
My second question: It seems 220.16 is saying we must add the load to the existing load calculation rather than recalculating and applying demand factors. Suppose in another instance, we add a new fastened-in-place appliance. If the house already has 4 or more, does this mean I cannot apply the 75% demand factor per 220.53? 220.16 seems to simply say I must use 220.14(A) and simply add the specific appliance load to the calculation. But the two scenarios give separate results. Which is it?
