Dwelling service load calculations over 225A

[SodapopSparky]

Newly minted Michigan journeyman here, trying to put together a load calc for this large residential rough job my company has landed. Through all my calculations, I’ve found the service is 350A to the house, accurate, but the NEC Standard Electrical Load Calculation for Single Family Dwellings is only up to 225A max. So I was wondering if there is a different form I should be using to calculate their service load? Also, I have to fill out a Large Residential Service Information load sheet for DTE, and though I have searched the green book, I cannot find what specific values they want in each field. Any help is much appreciated, thank you in advance!

 

[tom baker]

Try the Optional Load calculation. annex D

 

[augie47]

Where do you find the "NEC Standard Electrical Load Calculation for Single Family Dwellings is only up to 225A max"

 

[SodapopSparky]

Where do you find the "NEC Standard Electrical Load Calculation for Single Family Dwellings is only up to 225A max"

Says so at the top of the form, in parentheses. Curious what type of load calculations people do for mansions and the like, this house has 6 small appliance circuits which most online load calculators for standard dwelling only allow you to put up to 4 I noticed.

 

[SodapopSparky]

Try the Optional Load calculation. annex D

I’ll give it a shot, thank you!

 

[ron]

Says so at the top of the form, in parentheses. Curious what type of load calculations people do for mansions and the like, this house has 6 small appliance circuits which most online load calculators for standard dwelling only allow you to put up to 4 I noticed.

What Article 220 form are you using that was issued by the NFPA?

 

[tom baker]

Almost always the optional calculation results in a smaller load for under 200 amps. Over 200 amps is not my area of experience

 

[SodapopSparky]

What Article 220 form are you using that was issued by the NFPA?

I was just going back and forth with my boss about that, I’m actually not sure where the form I’m using is pulled from. It is what my instructors in school gave me to do load calculations on, and what I’ve seen tossed around. The text at the top is what has thrown me off, flipping through 220 in the 2017NEC I don’t see anything limiting the calculations at 225A.

 

[SodapopSparky]

Almost always the optional calculation results in a smaller load for under 200 amps. Over 200 amps is not my area of experience

Appreciate the responses anyhow, the optional calculation seems to be much faster to do so that alone was a good thing to revisit.

 

[ron]

I was just going back and forth with my boss about that, I’m actually not sure where the form I’m using is pulled from. It is what my instructors in school gave me to do load calculations on, and what I’ve seen tossed around. The text at the top is what has thrown me off, flipping through 220 in the 2017NEC I don’t see anything limiting the calculations at 225A.

Looks like the City of Los Angeles from the website linked at the bottom of the form, but that doesn't make it right.

https://www.ladbs.org/docs/default-source/forms/inspection-forms/sfd-electrical-vehicle-charger-service-load-calculation-form-in-form-00.pdf?sfvrsn=1ca8e453_20