Sccr Calculation -

For a 5 kA rated contactor, if the let-through I²t of the fuse ≤ the I²t withstand of the contactor (or per Table SB 4.1), the contactor can be considered rated at (e.g., 200 kA) but only if the manufacturer allows series rating.

7. Final Rule Summary Panel SCCR = - Lowest SCCR in power circuit (default method) OR - SCCR of current-limiting fuse if all downstream components: a) Have SCCR ≥ 5 kA, and b) Are not power conversion equipment (VFDs, etc.), and c) Manufacturer series rating exists or UL 508A Table SB4.2 allows it. 8. Quick Formula for Engineers Without current-limiting: [ SCCR_panel = \min(SCCR_1, SCCR_2, ..., SCCR_n) ] sccr calculation

If ( SCCR_fuse \geq 100 \text kA ) and ( SCCR_component \geq 5 \text kA ), then ( SCCR_effective = SCCR_fuse ) for that branch. For a 5 kA rated contactor, if the