scope:

Foreword 

This standard defines high-potential test requirements for excitation systems for synchronous machines. IEEE Std 421B-1979 established test voltages as a function of exciter output circuit and for all other circuits electrically isolated from the exciter output circuit. This standard was written to agree with existing standards as much as possible but expands the test voltages to account for stresses associated with high ceiling exciters.

Scope

This standard applies to high-potential testing of complete excitation systems and their components for synchronous machines. The components of the excitation system are described in IEEE Std 421.1-1986. Also included are auxiliary devices that are exposed to excitation system stresses. On static exciters, auxiliary devices connected to both the input and output side of the rectifier bridge are exposed to similar excitation system stresses. Examples of such auxiliary devices are temperature indicators, transducers, meters, etc. This standard does not cover the synchronous machine field winding or field circuit breaker and discharge resistor since appropriate standards exist for these devices.