optional calculation for apartment unit

[jimingram]

Re: article 220.30 Optonal Calculation-Dwelling Unit

Is it permissible to use the above section to calculate the load in an individual apartment unit? Each unit has a single feeder, 120/208 volts, electric range, dryer, dishwasher, disposal, microwave, air conditioning, and electric heat. The ampacity is over 100 amps.

The examples in Annex D give optional calculations for the whole building not individual units. This ommission is causing me to question if I can use the optional calculation for a single unit.

 

[earlydean]

Re: optional calculation for apartment unit

The optional method given in 220.30 applies to a single dwelling unit, whether it is a separate building or located in a multifamily dwelling.

from the 2002 Handbook

Sound like you are mistaken about Annex D. Look a little closer.

 

[bob]

Re: optional calculation for apartment unit

Jim
Look at D5 caculations. The only difference is that you would caculate the apartment load as a 3 phase load rather that single phase load.