Slash rating

The slash rating, under the National Electrical Code, is given to circuit interrupt hardware and specifies a maximum line-to-ground voltage rating in combination with a maximum line-to-line voltage rating. One common application would be for a three-phase electrical loads. For example a 120/240V rating can disqualify a circuit breaker for use with a delta system load that would otherwise work with a wye system load.

References

* [http://bg.ecmweb.com/ar/electric_art_overcurrent_protection/index.htm Code Basics: Electrical Construction & Maintenance, Feb 1, 2004] , by Mike Holt, NEC Consultant;
* [http://www.iaei.org/subscriber/magazine/02_b/manche.htm Overcurrent Protection and the NEC]