| 摘要 |
A reclosing system for d-c feeder breakers in transit systems employing cars using a chopper type of regulated power is disclosed. The circuit includes voltage-sensing and load-measuring circuits which determine that there is no short circuit on the respective feeder line before the circuit breaker can be closed. The system operates in two sequential modes. The first is a voltage-sensing mode which, upon sensing a voltage on the feeder circuit greater than some given magnitude, will cause the closing of the feeder breaker. If this voltage is not sensed during the voltage-sensing mode, the circuit automatically goes into a load-measuring mode wherein a current is injected into the feeder circuit and the voltage drop caused by the injected current is monitored. If a sufficiently high voltage is produced, which indicates that the feeder circuit is free of a fault, the feeder breaker is closed.
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