Why is Short-Circuit Current Rating Important? Short-circuit current ratings provide the level of fault current that a component or piece of equipment can safely withstand (based on a fire and shock hazard external to the enclosure). Without knowing the available fault current and short-circuit current rating, it is impossible to determine if components or equipment can be safely installed.
Reimers uses components that allow high SCCR ratings. Reimers builds many types of electric boilers for steam and hot water. Electric Steam BoilersThe 2008 NEC® has a new definition of “short-circuit current rating”. Previously there was no definition of short-circuit current rating (sometimes referred to as “withstand rating”), although it was referenced in several sections on the marking and proper application of various types of equipment. Because the term is referenced in multiple locations of the Code, it was necessary to add a definition to Article 100 of the NEC®. What is Short-Circuit Current Rating? Short-circuit current rating (SCCR) is the maximum shortcircuit current a component or assembly can safely withstand when protected by a specific overcurrent protective device(s) or for a specified time. Adequate short-circuit current rating is required per 110.10.
When analyzing assemblies for short-circuit current rating, both the interrupting rating of overcurrent protective devices and the short-circuit current rating of all other components affect the overall equipment short-circuit current rating. For instance, the short-circuit current rating of an industrial control panel typically cannot be greater than the lowest interrupting rating of any fuse or circuit breaker, or the lowest short-circuit current rating of all other components in the enclosure.