Strategies for mitigating the effects of internal arcing faults in medium-voltage metal-enclosed switchgear

There are numerous strategies currently employed to mitigate the effects of an internal arcing fault in medium-voltage metal-enclosed switchgear. As we learn more about the behavior of the arcing fault and how the switchgear and installation affect the severity of the fault, it is recognized that many of the techniques may be combined to improve performance. A review of the internal arcing fault and mitigation techniques is provided with discussion on how these techniques may be combined to produce positive results. When the mitigation technique has a response time that is longer than the rise time of the internal overpressure phenomenon associated with arcing faults, a need for structurally enhanced switchgear exists. A new test guide for measuring the structural enhancements is offered and strategies for coordination of arc resistant construction with mitigation techniques are discussed.