Help (please) with a load calculation

Location
northern illinois
Occupation
supervising electrician
Hey guys, I need a bit of help with a load calculation.

The building is thus: 2 story, with 2 stores on the first floor ( 1 rented, 1 vacant). 2 apartments on the second floor .(both rented). Th current service is 200 amp single phase (I know it is too small)

Here is what I need help with.... the apartment load calculations.... I am having problems applying the demand factors, and the numbers I am getting just look way too big, considering they are about 40+years old, and havent had any noticeable remodeling.

LOAD CALCULATION:
2 identical apartments of approximately 1250 square feet.

32 feet electric baseboard heat @ 250 W/ft
1 electric range @ 10kW (nameplate rating)
1250 sq ft x 3W/ sqr ft
2 small appliance circuits @ 1500 VA each


1 electric heat 8kW
2 electric range 10kW
3 general ltg 3.75kW
4 small appliance 3.0kW


Thank you

Howard
 
Location
northern illinois
Occupation
supervising electrician
Here is what I came up with.....

Gen ltg @ 3750VA
Sml Appl@ 3000VA

Sub TTL 6750VA

!st 3000VA @ 100% 3000VA
3750VA @ 35% 1312.50VA

Total Load without range 4312.50 VA

Range Load 10kW x.11 (demand factor) 1100VA

Heating load 8000 VA

Total Load per APT: 13412.5 VA

13412.5 VA / 240 = 55.88 Amp


This doesnt look right to me..... But this hasnt been a week to guess at things.......


Howard
 

david luchini

Moderator
Staff member
Location
Connecticut
Occupation
Engineer
Here is what I came up with.....

Gen ltg @ 3750VA
Sml Appl@ 3000VA

Sub TTL 6750VA

!st 3000VA @ 100% 3000VA
3750VA @ 35% 1312.50VA

Total Load without range 4312.50 VA

Range Load 10kW x.11 (demand factor) 1100VA

Heating load 8000 VA

Total Load per APT: 13412.5 VA

13412.5 VA / 240 = 55.88 Amp


This doesnt look right to me..... But this hasnt been a week to guess at things.......


Howard
Range demand is 8kW, not 1.1kW.
 

kwired

Electron manager
Location
NE Nebraska
The range demand is 8 kW for feeder to one apartment.

The range demand for both apartments and main feeder/service is only 11kW.

Other demand factors possibly apply to the entire main feeder/service that don't apply to individual units as well.
 
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