Apparatus having automatic re-set means for detecting a fault current

Claim 1

A device for detecting that a fault current of at least a given value has passed a point on the circuit conductor and for storing that information for future interrogation for the purpose of locating the locality of a fault, comprising, current transformer means for sensing the current in the conductor, means for converting said sensed current into a proportional voltage signal, first relay means having first and second latched positions, actuating means responsive to said voltage signal disposed to actuate said first relay means from either position it may occupy to said first positions when said voltage signal is below the level corresponding to said given value of the current and to said second position when said voltage signal is at and above the level corresponding to said given current value and to maintain the relay in its previously latched position in the absence of a voltage signal, said actuating means including voltage sensitive diode means coupled to said converting means and adapted to conduct only at and above the voltage corresponding to said given current value, and second relay means connected to and operated by said voltage sensitive diode means for controlling the actuation of said first relay means, and means operably connected to said first relay means disposed to indicate which position said first relay means is in.

Claim 2

A device for detecting that a fault current of at least a given value has passed a point on the circuit conductor and for storing that information for future interrogation for the purpose of locating the locality of a fault, comprising, current transformer means for sensing the current in the conductor, means for converting said sensed current into a proportional voltage signal, first relay means having first and second latched positions, actuating means responsive to said voltage signal disposed to actuate said first relay means from either position it may occupy to said first positions when said voltage signal is below the level corresponding to said given value of the current and to said second position when said voltage signal is at and above the level corresponding to said given current value and to maintain the relay in its previously latched position in the absence of a voltage signal, said actuating means including voltage sensitive diode means coupled to said converting means and adapted to conduct only at and above the voltage corresponding to said given current value, and second relay means connected to and operated by said voltage sensitive diode means for controlling the actuation of said first relay means, and means operably connected to said first relay means disposed to indicate which position said first relay means is in.