Residential Load Calculator

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krmelectricbwm

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Does anyone know if there is a residential load calculation spreadsheet online that I can use to calculate an apartment's loads? I am attempting to calculate the required sub-panel size for an upcoming apartment renovation. (See earlier post) I tried to use the calculator that Mike has on his site but I could not figure out how to eliminate the already inputted pool loads that were cell protected. Thank you everyone in advance for their great advice!!!
 
Re: Residential Load Calculator

Follow these 9 easy steps to determine dwelling load requirements:

STEP 1 Square footage living area x 3va. (Table 220.3A)

STEP 2 Small appliance = 2 x 1500 va. Laundry = 1500va.

STEP 3 Apply lighting demand to steps 1 & 2. (Table 220.11)

STEP 4 Compare heat with A/C. Omit smaller load. (220.21)

STEP 5 75% demand for 4 or more fixed appliances. (220.17)

STEP 6 Dryers at 5kw minimum. (220.18) Neutral demand at 70%. (220.22)

STEP 7 Demand for cooking equipment. (220.19) Neutral at 70%

STEP 8 Largest motor is to be increased 25%. (220.14)

STEP 9 Size the service by dividing the total va by the applied voltage and apply Table 310.15b6. Use Table 250.66 to size grounding electrode conductor
 
Re: Residential Load Calculator

Thank you again Bryan,

I printed out your response and will add it to my code book. It looks like I will calculate the load both with and without Step 6 to determine the electric dryer's additional load and present it that way to the customer. Would Step 8 also apply to the HVAC equipment again if that was the largest motor present?
 
Re: Residential Load Calculator

Hey guys,

Still playing with these numbers. I apologize for my ignorance in advance. What nameplate rating am I supposed to use for the HVAC calculation? Do I refer to the minimum circuit ampacity, the run load amperage, or max fuse/ocpd size? Or do I just use the largest of the values given? I would really like to know so that I can do this confindently in the future, especially when it comes to exam time. Thank you for patience and great advice Bryan and Bwyllie.
 
Re: Residential Load Calculator

to calculate the kva of the load you would use the run load amps. Min circuit amps is used for wire size.
 
Re: Residential Load Calculator

Sounds good to me. I wasn't sure and have seen some load calculations done with a generic load rating such as the breaker size for the HVAC. Thank you for clearing that up Bwyllie.
 
Re: Residential Load Calculator

Cieling fan,Garbage disposal, Dishwasher ,sump pump, Furnace are all examples of fixed appliances. Correct?
 
Re: Residential Load Calculator

Also say we have gas heat and AC do you multiply the AC load by 125% assuming its the largest motor. I assume RLA on AC unit stands for Run Load Amps
 
Re: Residential Load Calculator

Originally posted by jes25: Ceiling fan, Garbage disposal, Dishwasher, sump pump, Furnace are all examples of fixed appliances. Correct?
Click to expand...
I would not agree with the ceiling fan or the furnace. I am not at my office right now, so I can?t look it up, but I don?t think these two would meet the definition of ?appliance.? When trash compactors were the rage, you could have included them as an appliance.
 
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