240.21(B) (2) (1) STATES: The ampacity of the tap conductors is not less than one-third of the rating of the overcurrent device protecting the feeder conductors.

200amps / 3 = 67 amps required for the tap conductors ampacity. The 60 amp disconnect termination is listed 75 degrees F. The tap conductors being used will be THHN. The THHN 75 degree ampacity for # 6 is 65 Amps so it does not meet the 67 amps. But can’t the ampacity value of the #6 at 90 degree C. column of 75 amps be used to satisfy 1/3 rating of the tap conductors on the feeder? It seems the 60 amp overcurrent device will keep the conductor from exceeding the termination rating of the 60 amp disconnect. So would a number 6 conductor meet the requirement and be able to be used for a 60 Amp fusible disconnect in this case?