es1451

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es1451

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1. Two individual motor circuits installed in the same conduit for two 25 hp 3 phase 208-volt Design B motors in an area with an ambient temparature of 40 degrees Celsius using THW conductors what is the following:

a. Minimum ampacity of branch circuit conductors

b. Minimum wire size for each branch circuit

2. A warehouse has a lighting load of 10,000 va. there are in addition, sixty receptacles throughout the building. What is the demand on the service conductors ?

Need clear and concise step by step solution to these two questions

Help me out my Brothers!!!

es1451

I've sent another post with my calculations dealing with these two questions check to see if they are right
thank you
 
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kingpb

kingpb

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SE USA as far as you can go
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Engineer, Registered
It was better then telling him we don't answer DIY questions. Oops, sorry it seems that has become politically incorrect to say....

I know, I know that was a little rough!
 
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es1451

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a.74.8 x 1.25 = 93.5
93.5 / .88 / .80 = 133 Amps

b. 133 Amps = 1/0 awg.


a.lt. load = 10,000 va
b.recept = 10,800 va
c.total = 20,800 va
d. 12,500 @ 100% =12,500 va
e. 8300 @ 50% = 4150 va
f. total = 16,650 va
g. 16,650 / 120 = 138.75 amps
 
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es1451

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I have posted my calculations I hope they are right, what was confusing me was when to use the corection and adjustment factors and at what point in my calculations and when to divide or multiply to get the correct ampacity
 
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es1451

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Chicago
Code Calculations

Code Calculations

the service voltage is 240/120 single phase , what would it be if it was three phase
 
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