Field protector for synchronous machines

摘要

Apparatus for overvoltage protection of the field winding of a synchronous dynamoelectric machine. A protective spark gap device is electrically connected in parallel across the field winding of the machine and is designed to weld itself into a short-circuit when the voltage across the field winding increases to an unacceptable value. The weldable spark gap provides a positive indication of problems in the field circuit and at the same time protects the field circuit from damage from continued operation. The protective spark gap is not self-restoring and therefore must be removed and replaced before operation is resumed.