How To Calculate Sccr May 2026

Check if the 5kA contactor and overload are listed with the Class J fuses. No direct series rating exists. But UL 508A Table SB4.1 says a contactor with a 5 kA SCCR can be raised to 100 kA if protected by a Class J fuse ≤ 60A, with available fault ≤ 200 kA.

Result: (limited by terminal block, unless terminal block also raised). how to calculate sccr

What is SCCR? The Short-Circuit Current Rating (SCCR) is the maximum short-circuit current a component or assembly can safely withstand without creating a safety hazard (e.g., fire, arc flash, or component rupture). In industrial control panels, the SCCR must be high enough to handle the available fault current at the point of installation. Check if the 5kA contactor and overload are

Terminal block manufacturer may also provide higher SCCR with Class J fuses. If not, replace terminal block with a 100 kA rated block. Result: (limited by terminal block, unless terminal block