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Discussion Starter · #1 · (Edited)
We are sizing 3PH service with 120/208 panel and about 40KVA of single phase loads all 120v. I took all loads with 100% demand factor according to code. Architect budgeted for a 3PH 100AMP...What do you think ?
 

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We are sizing 3PH service with 120/208 panel and about 40KW of single phase loads all 120v. I took all loads with 100% demand factor according to code. Architect budgeted for a 3PH 100AMP...What do you think ?
It appears some info maybe missing, kinda hard to tell without having some idea what loads are there (motors continuous loads 125%etc?? . Is this a school, store, what??

Are you sure none of these loads are continuous in accordance with a feeder calculation?... Also, you might be able to use demand factors that would not require some things at 100%
even with a basic 3 ph calc, at 100% I get

40,000/(208*1.73)=111.16 amps

Need more 'data' ;)
 

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Discussion Starter · #4 · (Edited)
Its a office/warehouse. I checked code and its looks like with the given square footage all general and lighting loads are 100% and all specified loads also at 100%. No motors, just computers, TVs, and big commercial printers and copiers.

Yes its 40 of single phase loads split on 3 phases. Is that as simple as 111amps per phase and just balance all loads among 3 phases ?
 

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balance the kws on the phases and then you will know
 
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