Short-Circuit Current Ratings
Short-Circuit Current Rating ... or SCCR
Short-Circuit Current Ratings (SCCRs) on components and equipment represent the maximum level of short-circuit current that the component or equipment can withstand. This rating can be marked on individual components or assemblies. Short-Circuit Current Rating markings are required in UL 508A, the 2007 edition of NFPA 79 and by NEC® sections 409.110, 430.8, 440.4(B) and 670.3(A), and are intended to represent the amount of fault current an assembly can withstand to ensure proper installation. The UL 508A standard documents the accepted procedures for calculating panel and assembly short-circuit current ratings. In the Cooper Bussmann SCCR section below you will find educational literature discussing these Code requirements and agency standards, along with a number of products and services to help with issues surrounding SCCR.
2008 NEC® SCCR Requirements
The National Electrical Code® has several sections containing requirements for marking equipment with short-circuit current ratings. These requirements, along with the fundamentals of SCCR, are covered in this document.
Below are documents published by Bussmann that address the requirements and methods related to Short-Circuit Current Ratings.
- Industrial Control Panel SCCR Tutorial
- Simplified Guide to Understanding SCCR
- SCCR case study whitepaper
When working with panel Short-Circuit Current Rating markings there are some common issues. Certain components can be very limiting to your overall panel rating, and the method of calculating the panel rating itself can be confusing. Cooper Bussmann has addressed both of these issues with the products, services and programs found below. The award-winning Bussmann series OSCAR™ compliance software is a tool that calculates assembly SCCR ratings based on component information.