| 摘要 |
An overcurrent signal is replicated by current mirrors for joint processing by a long-time trip mode network and a short-time trip mode network pursuant to initiating a circuit breaker trip function after an adjustably predetermined delay predicated on the overcurrent signal magnitude. The former network measures signal against a sloping I2t portion of an established trip time curve, while the latter optionally measures the overcurrent signal against a second I2t curve portion terminating in a selected one of plural fixed time delay curve portion. Short-time delay zone selective interlocking between upstream and downstream breakers and long-time delay pickup indication are also disclosed.
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