Short Circuit Current Ratings (SCCR) for UL508A and NEC

Code and Standard requirements for short-circuit current ratings

In accordance with Article 409.22 (B), the short-circuit at the incoming supply terminal of the industrial control panel shall be calculated and this calculation shall be documented with the respective date of calculation. This documentation shall then be submitted to the inspector upon acceptance of the equipment.


High capacity short circuit current ratings

High capacity short circuit current ratings for Siemens IEC based industrial control equipment and accessories

High capacity short circuit current ratings for Siemens NEMA Contactors & Overload Relays

High capacity short circuit current ratings for Siemens solid state soft starters  

High Capacity Short Circuit Ratings for Siemens Circuit Breaker, IEC Contactor and OLR Combination Ratings


Ip (Peak-let-through current) curves for Siemens current limiting Circuit Breakers

Siemens Current Limiting Circuit Breakers offer additional advantages when trying to maximize the SCCR for your control panel. However Circuit Breakers are only considered as current limiting if they are:

  • Applied in the ‘feeder circuit’

  • Marked as “current limiting”

Please open and review the SCCR White Paper for more details how to apply and to use them.

The file below provides the Peak let-through p) Curves for the following Current Limiting Circuit Breakers: CED6, CFD6, CJD6, CLD6, CMD6, CND6, CPD6, SCJD6, SCLD6, SCMD6, SCND6.

Siemens Current Limiting Circuit Breakers Peak let-through curves

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