摘要:
An integrated circuit breaker is provided with shunt trip capability along with automatic overcurrent protection through the circuit breaker trip unit and shunt trip module. The shunt trip module further provides auxiliary power to the trip unit and allows the trip unit microprocessor to report and record the shunt trip operation. The trip unit communicates with the circuit breaker operating mechanism to determine the ON-OFF status of the circuit breaker contacts.
摘要:
A remotely controlled circuit control device has first and second load contact assemblies movable into circuit engagement and circuit disengagement positions relative to one another in which one load contact assembly is operatively connected to a solenoid so that alternate forward strokes of the solenoid moves the one load contact assembly between reset and tripped positions through a push-push mechanism having an indexing portion and a latching portion. An overload mechanism cooperates with the latch portion to cause the load contact assemblies to move to the circuit disengaged position upon occurrence of a fault condition. The second load contact assembly includes pivotably mounted contact members which are linked to the first load contact assembly in such a way that circuit engagement during solenoid energization is precluded. The push-push mechanism is operatively connected via a mode switch to either a reset circuit or a trip circuit and in turn to a remotely disposed indicator-control unit (ICU) through an optical coupler. Contact status and coordination between load contacts and ICU contacts are provided by a feedback circuit. An interface circuit allows operation of the circuit control device without discrimination on a power supply of either alternating or direct voltage or both. Life expectancy of the device is enhanced by several features including double break contacts with contact wiping and the provision of a floating output arm for the solenoid.
摘要:
Control apparatus is provided for a contactor which has a coil and at least one pair of contacts movable from an open position to a closed position in response to energizing the coil. The control apparatus includes apparatus for temporarily and permanently energizing the coil and switching apparatus for controllably energizing the coil.
摘要:
A digital network protector relay samples the polyphase current, network voltage and phasing voltage at 16, and preferably 32, times per cycle so that up to the seventh and fifteenth harmonics, respectively, are eliminated from the sequence calculation used to make trip and close decisions. The relay also provides metering, forward overcurrent protection, and an anti-pumping feature, the latter of which locks the circuit breaker out if a selected number of breaker operations is exceeded during a given time interval. Sequential sampling of the polyphase current and voltages by a single analog to digital converter reduces the cost of the relay. In order to accommodate metering and extraction of the fundamental components of the current and voltages for the sequence calculations, the polyphase current and network voltage are sampled sequentially in a first order for a given number of cycles and then in a second reverse order for the same given number of cycles.
摘要:
A reclosing relay for reclosing a circuit breaker in an electrical power system. The reclosing relay is a multi-shot reclosing relay (i.e., providing more than one reclosure command to the circuit breaker) and includes primary and redundant lockout circuits for each reclose circuit. The primary lockout scheme employs a flip-flop, with a reset timer for resetting if the breaker remains closed after the first reclosure. The flip-flop is set when the circuit breaker recloses to lockout the first reclosure circuit. The redundant lockout circuit locks out the first reclosure circuit after a trip, reclose, and retrip sequence. The second reclose circuit includes similar primary and redundant lockout circuits.