TRANSFORMER TESTING METHOD

摘要

Testing of a transformer in an oil filled housing is done by providing an external arrester insulator/isolator penetrating and making an electrical connection through the housing while preventing leaking of oil from said housing. An arrester inside said housing is electrically coupled between an interior end of arrester isolator and a predetermined potential point within the housing. An exterior end of said arrester isolator is removably and electrically coupled to a ground potential point. The ground coupling is removed from the exterior end of the arrester isolator and the transformer is tested by measuring electrical characteristics on transformer connections emerging from the housing. The ground coupling is reconnected to the exterior end of the arrester isolator after testing is completed. If required, an insulating cap may be applied to the external isolator to provide additional withstand capability to external flashover during the tests.