Max locked rotor current

[JRM_CA]

I have a problem to size a disconnect, I need to find the max locked-rotor current for a code Design C type 3 phase squirrel cage induction motor rated 15 HP, 230 V. 

The solution tells me to look it up in the tables for 430.251.  I understand that answer, but if I choose to use an equation and NEC Table 430.7(B) for the Locked Rotor Indicating Code Letters,then I get a very different answer than what is in the NEC in the tables for 430.251. 

Locked Rotor Current = Locked-rotor KVA / (1.73 * kV) ... The equation I am getting out of the NEC Handbook.

The answer is completely different than later on. What am I not understanding about these tables?

 

[Ship Wreck PE]

The tables are based on the most inefficient motor available. They want all wiring sized to this in case the maintenance man finds one of these beasts when changing out defective motor.