NHRider (Customer) asked a question.

May 8, 2021 at 11:53 AM
Circuit Breaker Descriptions and SCCR ratings

Many of your circuit breaker descriptions show an SCCR(e.g. FAZ-B63-3-NA). This bothers me a bit since neither fuses nor circuit breakers have SCCR ratings. They have interrupt ratings. This is significant when determining panel SCCR. It would be nice to see those descriptions updated to not say SCCR. Thanks.

  • 2 answers
  • 686 views

  • ADC Community_02 (Automationdirect.com)

    Thanks for your feedback! I have forwarded your suggestion to the Power & Circuit Protection Product Manager.

     

    You are correct. Fuses and circuit breakers have interrupting ratings. Contactors, terminal blocks and bus bars have SCCR. However, both ratings are used the same to calculate SCCR for the entire enclosure. UL 508A Table SB4.1 use SCCR (Short circuit Current Rating) to describe all of these the same.

     

    sccr 

     

    Expand Post
    • sccr

    • NHRider (Customer)

      The problem is that the lowest interrupt rating determines SCCR. The lowest SCCR is subject to let-through current of overcurrent protection device. Seem subtle, but the difference in terms is significant.

      Thanks,


      Leon Kenison
      Automatrix, Inc.
      Senior Controls Engineer
      lkenison@automatrixinc.com<mailto:lkenison@automatrixinc.com>
      603-867-5909
      Expand Post

 

Did this information resolve your issue?