Understanding 25% Largest Motor For Calcs

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wawireguy

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What if the question is residential with no specific motor load? Do I use the AC or disposal in that case for choosing 25% of my largest motor load? What if the AC is the largest motor load but is ommited due to heat being larger. Do I still include the 25% from the AC in my load calcs while ommiting the rest of the AC load?

What constitutes a motor load? AC, Disposal, Dryer? Given a 20 amp 120v AC and a 1HP 120v circulating motor which do you choose as your motor load?

I'll be taking the WA Admin test calcs section again before the end of the month.
 
wawireguy said:
What if the question is residential with no specific motor load? Do I use the AC or disposal in that case for choosing 25% of my largest motor load? What if the AC is the largest motor load but is ommited due to heat being larger. Do I still include the 25% from the AC in my load calcs while ommiting the rest of the AC load?

What constitutes a motor load? AC, Disposal, Dryer? Given a 20 amp 120v AC and a 1HP 120v circulating motor which do you choose as your motor load?

I'll be taking the WA Admin test calcs section again before the end of the month.
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That's a good question but I would think you only need to take 125% of the largest motor used in the calculations.
 
In the real world I would not be sweating a couple of watts either way but this test is a PIA. Dislike having to guess at what the test is wanting. The example with a AC and a circulating pump is almost verbatim from the test. So, do you choose the AC or the circ pump for your 25% motor load? Can't wait to pass this thing..
 
Was looking through Mcgraw Hills Illustrated Guide to the NEC at the bookstore and it showed not using a omitted load for your 25% addition to the largest motor. Said to use the next largest included load. Interesting how you get a different answer depending on who you ask..
 
wawireguy said:
In the real world I would not be sweating a couple of watts either way but this test is a PIA. Dislike having to guess at what the test is wanting. The example with a AC and a circulating pump is almost verbatim from the test. So, do you choose the AC or the circ pump for your 25% motor load? Can't wait to pass this thing..
Click to expand...

The motor with the highest HP rating.
 
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