Load calculation for Single family

[Leonan]

Hello, I would like your help. So there is a house with 200A service, and according to the calculation I made, 113A is the existing bottleneck. An addition will be made with a load of 118A. Can't install a subpanel for this? Just an upgrade to 320/400A?

Load calculation for Single family


Existing house
1141 sq ft x3W= 3423W
Small appliances 3000W
Laundry 1200W
Fridge 220W
Microwave 158W
Dish washer 888W
Disposal 900W
Stove 8000W
Dryer 5400W
Water heater 5500W

Total : 28690-10000= 18690x40=7476+10000=17476W
AC/heater Condenser: 40Ax240V= 9600W

17476W+9600W= 27076W/240V= 113A


Addition house
943sq ft x3w: 2829W
Small appliances 3000W
Laundry 1500W
Dish washer 1800W
Disposal 900W
Cooktop 8000W
Oven 4960W
Dryer 3360W
Water heater 5500w

Total: 31849-10000=21849x40%=8740+ 10000=18740W
Condenser AC/Heat 40Ax240: 9600W

18740+9600= 28340/240V= 118A

 

[tortuga]

Welcome to the forum.
Is this addition a apartment / mother-inlaw / 2nd dwelling unit?

Couple of observations so far
Is the microwave really 158 Watts?
The laundry should be 1500VA

 

[Leonan]

Welcome to the forum.
Is this addition a apartment / mother-inlaw / 2nd dwelling unit?

Couple of observations so far
Is the microwave really 158 Watts?
The laundry should be 1500VA

Sorry Microwave 1580W. It would be a single family with addition

 

[Leonan]

orry Microwave 1580W. It would be a single family with addition

 

[tortuga]

So its a one family dwelling with two kitchens, two laundry rooms etc?
Id just throw all those numbers in the optional (220.82) Calc for the service size:

​	220.82 Optional Dwelling calc​
​	Load​	Qty​	VA​	Amount​	Code Ref​
​	Existing​	1141​	3​	3423​	220.82(B)(1)​
​	Addition​	943​	3​	2829​	220.82(B)(1)​
​	Small appliance​	4​	1500​	6000​	220.82(B)(2)​
​	Laundry​	2​	1500​	3000​	220.82(B)(2)​
​	Fridge​	1​	220​	220​	220.82(B)(3)​
​	Microwave​	1​	1580​	1580​	220.82(B)(3)​
​	Dish washer​	1​	888​	888​	220.82(B)(3)​
​	Dish washer new​	1​	1800​	1800​	220.82(B)(3)​
​	Disposal​	2​	900​	1800​	220.82(B)(3)​
​	Range​	1​	8000​	8000​	220.82(B)(3)​
​	New cooktop​	1​	8000​	8000​	220.82(B)(3)​
​	New Oven​	1​	4960​	4960​	220.82(B)(3)​
​	Dryer​	1​	5400​	5400​	220.82(B)(3)​
​	Dryer New​	1​	3360​	3360​	220.82(B)(3)​
​	Water heater​	2​	5500​	11000​	220.82(B)(3)​
​	​	​	​	62260​	220.82(B)​
​	​	​	- first 10kw​	-10000​	220.82(A)​
​	​	​	​	52260​	220.82(A)​
​	​	​	40.00%​	20904​	220.82(A)​
​	​	​	+ First 10kw​	10000​	220.82(A)​
​	​	​	Subtotal​	30904​	220.82(A)​
​	​	​	​	​	​
​	HVAC​	2​	9600​	19200​	220.82(C)​
​	​	​	​	​	​
​	​	​	​	50104​	Total​
​	​	​	​	209​	Amps​

 

[Leonan]

So its a one family dwelling with two kitchens, two laundry rooms etc?
Id just throw all those numbers in the optional (220.82) Calc for the service size:

​	220.82 Optional Dwelling calc​
​	Load​	Qty​	VA​	Amount​	Code Ref​
​	Existing​	1141​	3​	3423​	220.82(B)(1)​
​	Addition​	943​	3​	2829​	220.82(B)(1)​
​	Small appliance​	4​	1500​	6000​	220.82(B)(2)​
​	Laundry​	2​	1500​	3000​	220.82(B)(2)​
​	Fridge​	1​	220​	220​	220.82(B)(3)​
​	Microwave​	1​	1580​	1580​	220.82(B)(3)​
​	Dish washer​	1​	888​	888​	220.82(B)(3)​
​	Dish washer new​	1​	1800​	1800​	220.82(B)(3)​
​	Disposal​	2​	900​	1800​	220.82(B)(3)​
​	Range​	1​	8000​	8000​	220.82(B)(3)​
​	New cooktop​	1​	8000​	8000​	220.82(B)(3)​
​	New Oven​	1​	4960​	4960​	220.82(B)(3)​
​	Dryer​	1​	5400​	5400​	220.82(B)(3)​
​	Dryer New​	1​	3360​	3360​	220.82(B)(3)​
​	Water heater​	2​	5500​	11000​	220.82(B)(3)​
​	​	​	​	62260​	220.82(B)​
​	​	​	- first 10kw​	-10000​	220.82(A)​
​	​	​	​	52260​	220.82(A)​
​	​	​	40.00%​	20904​	220.82(A)​
​	​	​	+ First 10kw​	10000​	220.82(A)​
​	​	​	Subtotal​	30904​	220.82(A)​
​	​	​	​	​	​
​	HVAC​	2​	9600​	19200​	220.82(C)​
​	​	​	​	​	​
​	​	​	​	50104​	Total​
​	​	​	​	209​	Amps​

Yes it’s a single dwelling with additions. I was thinking of doing 400a service, keep the 200a existing panel and add another panel 200