Sizing Wire: Based on Load or OCPD?

Edited

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Location
Arizona
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JW
In a few uncommon cases I've come across, the difference between the Load and the next size up OCPD is an entire wire size.
For example, the load is 130A and the next size OCPD is 150. If we're using THHW, there is a wire size for both 130A (1 Awg) and 150A(1/0)

So in a situation like this. Are you sizing your wire based off the actual load or the OCPD?
 
Note 210.19 and 215.2 which tell you the conductors must be sized to carry the load.
My guide was always 1. calculate the load 2. Select the conductor to carry the load 3. Select the OCP devoice to protect the conductor/
 
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