An American National StandardIEEE Guide for Synthetic Fault Testing ofAC High-Voltage Circuit Breakers Ratedon a Symmetrical Current BasisTo develop and test high-voltage circuit breakers to meet present and future system capabilities requires demonstrationof performance at power levels in excess of the capacity of test laboratories or utility systems. Various means havebeen developed in the past to extend test capabilities such as two part testing or unit testing. A major extension of testcapability results from the use of multiple source circuits.ANSI C37.06-1979, [1] 1, establishes current and voltage requirements which may not be possible to achieve on directtests. Multiple source circuits, generally identified as synthetic circuits, can achieve the required characteristics.1.2 Scope and PurposeThis guide is intended to provide a basis for synthetic testing of circuit breakers (see ANSI/IEEEC37.04-1979 [2]) andto establish the criteria for testing to demonstrate the short-circuit current rating of circuit breakers on a single phasebasis.It is recognized that other test requirements exist (such as capacitor switching, or line dropping) but they will bereserved for future consideration.The guide contains typical circuits for demonstrating interrupting capability. These circuits are those in general useand their inclusion should not exclude the development of additional circuits to demonstrate specific capabilities.The purpose of this guide is to establish criteria for synthetic testing and for the proper evaluation of results. Suchcriteria will establish validity of the test method without imposing restraints on innovation and improvement of testcircuitry.