When applying the optional methods of calculations for new restaurants, determine the maximum standard size main circuit breaker required for a restaurant that is all electric, with a connected load of 330 kva, and 208Y/120-volt, 3-phase, 4-wire service.
New restaurant optional method of calculation
- Thread starter Ivan1965
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- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Sounds like a test question. We prefer you gives us your answer first.
- Location
- Connecticut
- Occupation
- Engineer
175000va/208v/1.732=486a
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Just to help out
The table states 50% of the load over 325,000. Since we have a load of 330,000 then we only have 5,000 over.
50% x 5000 = 2,500
Table states to add 172,500
172,500 + 2, 500 = 175,000
208 x ^3 = 208 x 1.732 = 360
175,000/ 360= 486 amps
I agree with you, that is how I worked, same 500 amps service but you calculation is the correct one, thank you Sir.
That is how I worked, thank you Sr.
Thanks Dennis.
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