I'm re-practicing code questions from the practice exams I have, and there is one problem that I'm a bit confused about.

Complex Imaginary Exam 1 question 69 asks:

"Which is the largest allowable size for an overcurrent device to protect a #300 KCMIL, TW, 60-degree aluminum conductor feeding a 277 V load? Assume the conductor is in a steel conduit."

I can easily find the ampacity of this #300 KCMIL, 60-degree conductor using NEC Table 310.15(B)(16) --> the ampacity is 195 A.

Now, the given solution states that OCPD sizes normally cannot exceed conductor ampacity. So the answer here is 180 A OCPD size.

Now, I know that normally NEC Section 240.4 - Protection of Conductors normally DOES NOT allow using the next standard OCPD size above the conductor ampacity. BUT, there is one section in particular that I think may apply in using the next standard OCPD size above the conductor ampacity.

"NEC 240.4(B) Overcurrent Devices Rated 800 Amperes or Less: The next higher standard overcurrent device rating (above the ampacity of the conductors being protected) shall be permitted to be used, provided ALL of the following conditions are met:

(1) The conductors being protected are not part of a branch circuit more than one receptacle for cord-and-plug connected portable loads.

(2) The ampacity of the conductors does not correspond with the standard ampere rating of a fuse of a circuit breaker without overload trip adjustments above ins rating (but that shall be permitted to have other trip or rating adjustments).

(3) The next higher standard rating selected does not exceed 800 amperes."

From what I see here, NEC 240.4(B)(2) and (3) definitely apply here, since 195 A does not correspond to a standard OCPD size and the next standard size up is 200 A, which is less than 800 A.

For condition (1), the problem only states that the conductor feeds a 277 V load. Can I not just assume that this is just one load or one receptacle?

What are your thoughts on this?

Thanks for any input on this!