Performance Test of the Allgemeine Elektricitats Gesellschaft Free-Jet Air-Blast 220-Kv 2,500-Megavolt-Ampere Reclosing Circuit Breaker

Tests of a representative sample of this circuit breaker were made on the system of the Bonneville Power Administration in order to provide an opportunity for American manufacturers and operating engineers to study the operation of this circuit breaker in interrupting faults and line charging currents. A single pair of interrupting contacts in open air, ease of contacts visual inspection, maintenance and replacement attracted much attention and favorable comment, particularly from operating engineers. The circuit breaker successfully interrupted fault currents in about six cycles (average) as compared with three cycles of fast oil circuit breakers of American manufacture. Interruption of line charging current, although successful, was accompanied by many restrikes. It is hoped that these tests and the analysis of the test data will facilitate development of an American circuit breaker which will retain the favored features of the European prototype but will be faster in interrupting fault currents and practically free from restrikes in interrupting line charging currents.