A series rated system, which is permitted by NEC $?,$ is where a circuit breaker with an interrupting rating less than the available fault current is verified to be protected for available fault current greater than its interrupting rating by specific line$-$side fuses or circuit breaker$-$hence the term series combination rating, series rating, or series rating combination.

a$.$ Article $100$ definition

b$.110\mathrm{.}3($B$)$

c$.110\mathrm{.}9$

d$.240\mathrm{.}86$