I have a multifamily dwelling unit complex - 57 units. (With some common spaces - "House" loads). They are "Dwelling Units" by NEC definition.
I am applying 220.82 for the individual dwelling units. My calculations show 25,796va per unit. Dwelling unit is 208v/1.
I am applying 220.84 for the building service calc. Per 220.84 I calculate a large dwelling unit demand - 33,569va per unit.
Four questions:
First questions. The laundry will be a 120v/1 stackable washer / dryer within unit - 20amp. Do I apply the 1500va laundry circuit as well as the 1920va nameplate rating in my calculations?
Second questions - regarding 220.82(A), it does not appear to allow 3 phase service for the units. Is it possible to serve multiple units with a 3-phase feeder supplying 1 phase to the unit? Pros / Cons? Make more sense to route a 3-phase feeder and calc with standard method?
Third question: Calcs review, see any issues / mistakes? Here are the numbers from my Calculations. I did use (3) SA circuits. Rule of thumb on this? Mic, Toaster, coffee, Ref...
Forth questions: Can 220.84 be applied to a distribution panel that will serve multiple units... 8-10 units per distribution panel. I believe so as it is a "Service" to the units as it is 3 or more units.
220.82 Dwelling Unit:
(B)
1023 square feet x 3va- total 3069va
(3) SA circuits - total 4500va
(1) Laundry circuit - total 1500va
Appliances - nameplate
Dishwasher - total 1000va
Water Htr - total 4500va
Range - total 8000va
Washer/Dryer stack unit - total 1920va
24,489va - 10,000va (100 percent): 14,489va x 40 percent: 5,796va plus 10,000va - total 15,796va
(C)
Heating / Cooling unit - 10,000va
10000va plus 15,796va - Total Unit 25,796va - 208v/1 service - 124 amps.
220.084 Optional Method:
(C)(1)
1023 square feet x 3va- total 3069va
(C)(2)
(3) SA circuits - total 4500va
(1) Laundry circuit - total 1500va
(C)(3)
Dishwasher - total 1000va
Water Htr - total 4500va
Range - total 8000va
Washer/Dryer stack unit - total 1920va
(C)(4)
0
(C)(5)
Heating / Cooling unit - 10,000va
Total 34,489 x (Table 220.84 - 57 units) 24 percent - Total 471,810va
480v/3 service - 567 amps
Existing electrical service (Change of use building)... large office building to apartments. Will add house loads to this.
Thxs in advance.
I am applying 220.82 for the individual dwelling units. My calculations show 25,796va per unit. Dwelling unit is 208v/1.
I am applying 220.84 for the building service calc. Per 220.84 I calculate a large dwelling unit demand - 33,569va per unit.
Four questions:
First questions. The laundry will be a 120v/1 stackable washer / dryer within unit - 20amp. Do I apply the 1500va laundry circuit as well as the 1920va nameplate rating in my calculations?
Second questions - regarding 220.82(A), it does not appear to allow 3 phase service for the units. Is it possible to serve multiple units with a 3-phase feeder supplying 1 phase to the unit? Pros / Cons? Make more sense to route a 3-phase feeder and calc with standard method?
Third question: Calcs review, see any issues / mistakes? Here are the numbers from my Calculations. I did use (3) SA circuits. Rule of thumb on this? Mic, Toaster, coffee, Ref...
Forth questions: Can 220.84 be applied to a distribution panel that will serve multiple units... 8-10 units per distribution panel. I believe so as it is a "Service" to the units as it is 3 or more units.
220.82 Dwelling Unit:
(B)
1023 square feet x 3va- total 3069va
(3) SA circuits - total 4500va
(1) Laundry circuit - total 1500va
Appliances - nameplate
Dishwasher - total 1000va
Water Htr - total 4500va
Range - total 8000va
Washer/Dryer stack unit - total 1920va
24,489va - 10,000va (100 percent): 14,489va x 40 percent: 5,796va plus 10,000va - total 15,796va
(C)
Heating / Cooling unit - 10,000va
10000va plus 15,796va - Total Unit 25,796va - 208v/1 service - 124 amps.
220.084 Optional Method:
(C)(1)
1023 square feet x 3va- total 3069va
(C)(2)
(3) SA circuits - total 4500va
(1) Laundry circuit - total 1500va
(C)(3)
Dishwasher - total 1000va
Water Htr - total 4500va
Range - total 8000va
Washer/Dryer stack unit - total 1920va
(C)(4)
0
(C)(5)
Heating / Cooling unit - 10,000va
Total 34,489 x (Table 220.84 - 57 units) 24 percent - Total 471,810va
480v/3 service - 567 amps
Existing electrical service (Change of use building)... large office building to apartments. Will add house loads to this.
Thxs in advance.