Abstract: A circuit testing closer is capable of closing a power distribution circuit and interrupting the resulting current at the next current zero. Upon detecting a fault, the circuit testing closer is operable to open contacts to isolate the fault. Next, the circuit testing closer tests the faulted line to determine whether the fault has cleared. The circuit testing closer may generate a first test signal having a first polarity and a second test signal having a second polarity opposite the first polarity. Generation of the second test signal may be limited to occur when the first test signal indicates a fault.

Abstract: A circuit testing closer may include a fault isolating switching device coupled between a supply side and a load side of a power distribution system and a current pulse generator coupled in parallel to the switch to generate a current pulse within the power distribution system subsequent to a fault isolation for testing the power distribution system. The current pulse generator may include an electromechanical actuator, an electromagnetic actuator or a solid state switching device. The circuit testing closer may be a purpose-built combination device, or the fault isolating switching device and the current pulse generator may be separately coupled and commonly controlled devices. The fault isolating switching device may have continuous current rating greater than a continuous current rating of the pulse generating device.

Abstract: A circuit testing closer is capable of closing a power distribution circuit and interrupting the resulting current at the next current zero. Upon detecting a fault, the circuit testing closer is operable to open contacts to isolate the fault. Next, the circuit testing closer tests the faulted line to determine whether the fault has cleared. The circuit testing closer may generate a first test signal having a first polarity and a second test signal having a second polarity opposite the first polarity. Generation of the second test signal may be limited to occur when the first test signal indicates a fault.

Abstract: A manual trip control method and arrangement is provided to manually trip a plurality of circuit interrupters. Specifically, where the circuit interrupters include magnetic-actuator-driven vacuum interrupters including permanent magnets that hold the contacts of the circuit interrupter in the closed position via a plunger, a first of the circuit interrupters is manually tripped via movement of the plunger. To operate the remaining circuit interrupters to trip open, the voltage generated in the magnetic actuator of the first circuit interrupter is coupled to the magnetic actuators of the remaining circuit interrupters for tripping thereof.