Branch circuit, short circuit and ground fault protection for ac motor

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Chuck 1961

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I have a test question that reads no exceptions apply maximum standard size non delay fuse permitted for branch circuit short circuit and ground fault protection for AC motor where given the following: 2 hp- 120 volt single phase, continuous duty, nameplate current rating 22 amps.

Calculations give 72 amp
I chose 80 amps for the protection
The answer sheet said you must go down to 70 in this case
I could not find a reason why to go down in amperage
What is correct?
 
Chuck 1961 said:
I have a test question that reads no exceptions apply maximum standard size non delay fuse permitted for branch circuit short circuit and ground fault protection for AC motor where given the following: 2 hp- 120 volt single phase, continuous duty, nameplate current rating 22 amps.
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An 80A fuse would be allowed under exception no 1 to Table 430.52.

If "no exceptions apply" then I would say the max size would be 70A.
 
The right overcurrent protection

The right overcurrent protection

They did use 24 amp as stated in the table
But I understand now after going back and reviewing 430.52(C)1
With no exceptions!
 
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