Fault current circuit breaker - has trip current level characteristic evaluated to identify optimum response period.

摘要

The circuit breaker is designed to characteristic data that defines the max. allowable response time. The specified standard requires the leakage current trip to limit at a min. rating of 30 mA to be 200 msec, and at 60 mA to be 170-180 msec. At the max. trip level of 150 mA, the max. response time is 50 msec. By interpolating the characteristic an optimum limit of 90-100 mA is identified that simplifies the design specification. The minimum response time at a mains frequency of 50 Hz is greater than 8 ms. ADVANTAGE - Allows most favourable response delay to be used for design purposes.