Understanding electrical fault levels when specifiying electrical switchgear

Incorrectly rated circuit-breakers can present a serious risk of failure during operation under faulted conditions. Many electrical engineers often confuse the real meanings of the terms associated with short circuits and equipment ratings. They generally rely on manufacturers in selecting the correct switchgear for the intended application. This paper aims to provide the system designer and equipment purchaser with information to understand the dynamics of the electrical system under fault conditions so as to be able to make informed choices to correctly specify electrical switchgear.