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Discussion Starter · #1 ·
Can someone double check my math and code application.

Doing a load calc for a single service feeding 4 small apartment.

Sqft is per unit 1,050

I calculated GL to be 7,650

Fixed appliances are

Fridge 1500
Dishwasher 1500
Water heater 4500
Microwave 1500
Space heater 2400

Range 8000

Dryer 5000

No motor loads and heat pump is 11000

This is for a single unit.

I got around 572 amp service using the standard and around 350 using the iptio al method. Can someone verify my math. Please and thanks.
 

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Lighting- 3va x 1050 x 4 units= 12,600

Small appliance & laundry= 4,500 x 4= 18,000

Fridge 1500 x 4= 6,000
Dishwasher 1500 x 4= 6,000
Water heater 4500 x 4= 18,000
Microwave 1500 x 4= 6,000
Range 8000 x 4= 32,000
Dryer 5000 x 4= 20,000
_______________________________
118,600 va x 45%= 53,370va

53,370/240v= 222.375A

Used the optional method. Now, somebody needs to check MY math.:jester:
 

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Can someone double check my math and code application.

Doing a load calc for a single service feeding 4 small apartment.

Sqft is per unit 1,050

I calculated GL to be 7,650

Fixed appliances are

Fridge 1500
Dishwasher 1500
Water heater 4500
Microwave 1500
Space heater 2400

Range 8000

Dryer 5000

No motor loads and heat pump is 11000

This is for a single unit.

I got around 572 amp service using the standard and around 350 using the iptio al method. Can someone verify my math. Please and thanks.

1050 x 3va = 3150
Small appliance + laundry = 4500
Total = 7650 - 3000 = 4650 @ 35% = 1627.5
1628 + 3000 = 4628 for GL

GL 4628
Fridge 1500
DW 1500
WH 4500
Mwav 1500
ScH 2400
Range 8000
DRY 5000
Hpump 11000

Total 40028

40028 / 240 = 166.78a
 

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IslandGuy said:
HOW is the fridge 1500 w? That isn't a load calc, that's a freakin' guess.
Lol... What kind of fridges do they have on the islands?? Do you think he should ask the GC EXACT models of the fridges, toaster, dishwasher, etc being installed?? No, because no ones knows yet. Your correct in one thing, the fridge isn't a load calc, it's apart of the load calc. We use generic values for various appliances, clothes dryers, cooking, etc. to get an idea of what we're going to need. For residential, I'll list some common values below.

Examples:
- Clothes Dryers/5400va
- Heat/5000va
- water heater/4500va
- disposal/900va

Hope this helps Island guy. ;)
 

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Discussion Starter · #10 ·
Meter bank

That is the plan i was needing help on the single service coming in hitting a 4 pak meter bank and having 200 amp breakers feeding each units main panel.
 

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Discussion Starter · #13 ·
220.84(b)?

Maybe im having a brain fart, but in still confused at the article section. " house loads shall be calculated in accordance with part III of this article and dhall be in addition to the dweliing losds calculated in accordance eith table 220.84." What does this mean? What is the difference between dwelling unit load house loads?
 

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Maybe im having a brain fart, but in still confused at the article section. " house loads shall be calculated in accordance with part III of this article and dhall be in addition to the dweliing losds calculated in accordance eith table 220.84." What does this mean? What is the difference between dwelling unit load house loads?
My guess:

House load is the load of all 4 dwelling units together where the dwelling unit load are single, which I guess you factor at the 45% demand factor when sizing the service
 

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My guess:

House load is the load of all 4 dwelling units together where the dwelling unit load are single, which I guess you factor at the 45% demand factor when sizing the service
ETA: I closed my book already but I think they said this is optional.
 

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Sometime 5 minutes away from that book will make a big difference. I'm waiting for someone else to chime in on that last question though; I may be wrong, but that is my interpretation.
 

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Typically the "house load" is referring to the loads that are not specific to a certain dwelling. For example, a common hallway, exterior lighting, sprinkler systems, fire alarm systems, etc.
 
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