Written by Series-Rated System is when panelboards are marked with their short-circuit rating in RMS symmetrical amperes.
A series-rated panelboard will be determined by the main circuit breaker or fuse, and branch-circuit breaker combination tested in accordance to UL Standard 489. The series-rating will be less than or equal to the interrupting rating of the main overcurrent device, and greater than the interrupting rating of the branch-circuit overcurrent devices.
(See “Fully-Rated System.”)
