Industrial Control Panel SCCR (UL 508A)
The short-circuit current rating of an industrial control panel by the UL 508A weakest-link method: the panel SCCR is the LOWEST of its power-circuit components' individual ratings (and the feeder OCPD interrupting rating), not the main breaker -- one 5 kA contactor caps the whole panel. Checked against the available fault per NEC 409.110. A current-limiting fuse can raise a weak component's combination rating.
Formula and source
panel_sccr = min(component SCCRs, feeder OCPD interrupting rating); compliant when panel_sccr >= available_fault.
The UL 508A Supplement SB industrial-control-panel short-circuit current rating (weakest-link method), with NEC 409.110 / 110.10, by name.
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