Abstract: A fault indicator contained within a protective equipment closure of the type used to house pad-mounted components of a power distribution system detects the occurrence of a fault current in a monitored conductor and provides a light indication thereof. The fault indicator includes a circuit monitoring module, having an integral fault indicator flag module, and a remote fault indicator light module. A status-indicating flag is rotatably mounted in the integral fault indicator flag module. The flag is positioned in either a reset indicating position or a fault indicating position by a magnetic pole piece, which is magnetized in one magnetic direction or the other by momentary application of a current in one direction or the other to an actuator winding on the pole piece.

Abstract: A fault indicator for detecting the occurrence of a fault current in a monitored conductor and providing a light indication thereof includes a rotatably mounted indicator flag. The flag is positioned in either a reset indicating or a fault indicating state by a magnetic pole piece, which is magnetized in one magnetic direction or the other by momentary application of a current in one direction or the other to an actuator winding on the pole piece. A magnetically actuated reed switch in an auxiliary magnetic circuit comprising an auxiliary pole piece magnetized by the actuator winding and a bias magnet magnetically aligned to oppose the reset magnetic orientation and reenforce the trip magnetic orientation of the magnetic pole piece closes upon occurrence of the fault current to connect an internal lithium battery to an LED visible from the exterior of the fault indicator housing.

Abstract: A fault indicator for three phase sheathed cables includes a flexible collar unit which fits over the cable. Magnetic pole pieces within the collar unit having associated magnetic windings are aligned with the three conductors within the cable to produce signals indicative of the current level in each conductor. An alarm unit receives the signals and sounds an alarm in the event the current in any conductor exceeds a predetermined threshold level to indicate the occurrence of a fault. The voltage level of the current indicating signals may be utilized to align the magnetic core assemblies with the conductors.

Abstract: A waterproof current transformer for supplying current to electrical cable monitoring devices includes a core assembly for attaching a remote circuit module to a monitored conductor and provides a concentrated magnetic flux indicative of the current level in the conductor. To facilitate installation and removal of the current transformer from the conductor, the core assembly is formed by a plurality of laminations served together and arranged in a generally rectangular configuration and joined with a magnetically conductive interlocking connecting means. A means for resisting moisture is disposed about the transformer to enable an indefinite submersion time span.

Abstract: A fault indicator contained within a protective equipment closure of the type used to house pad-mounted components of a power distribution system detects the occurrence of a fault current in a monitored conductor and provides a light indication thereof. The fault indicator includes a circuit monitoring module, having an integral fault indicator flag module, and a remote fault indicator light module. A status-indicating flag is rotatably mounted in the integral fault indicator flag module. The flag is positioned in either a reset indicating position or a fault indicating position by a magnetic pole piece, which is magnetized in one magnetic direction or the other by momentary application of a current in one direction or the other to an actuator winding on the pole piece.

Abstract: A clamping mechanism for mounting a circuit conditioning monitoring device to electrical cables of various diameters includes a fixed sleeve and a movable sleeve positioned within the fixed sleeve. Both sleeves include gaps whereby an electrical cable may be pasted therethrough. The inner movable sleeve further includes a clamping means, preferably a tightening screw, whereby after a cable is passed through the gaps, the inner sleeve rotates within the outer sleeve to close the gap and further clamps onto the cable for secure mounting of the device.

Abstract: A fault indicator for detecting the occurrence of a fault current in a monitored conductor and providing a contact closure and a light indication indicative thereof includes a rotatably mounted indicator flag. The flag is positioned in either a reset indicating or a fault indicating state by a four-pole magnetic pole piece, which is magnetized to an appropriate magnetic orientation by momentary application of a current to an actuator winding on the pole piece. A first magnetically actuated reed switch in an auxiliary magnetic circuit associated with a first pole of the magnetic pole piece and including the actuator winding and a first bias magnet closes upon occurrence of the fault current to connect an internal lithium battery to an LED visible from the exterior of the fault indicator housing.

Abstract: A fault indicator for detecting the occurrence of a fault current in a monitored conductor includes a rotatably mounted indicator flag. The flag is positioned in either a reset indicating or a fault indicating state by a magnetic pole piece, which is magnetized in one magnetic direction or the other by momentary application of a current in one direction or the other to an actuator winding on the pole piece. An auxiliary magnetic circuit comprising an auxiliary pole piece magnetized by the actuator winding, a reed switch and a bias magnet magnetically aligned to oppose the reset magnetic orientation and reenforce the trip magnetic orientation of the magnetic pole piece provides contact closure upon occurrence of the fault current.

Abstract: A clamping mechanism for mounting a circuit condition monitoring device to electrical cables of various diameters includes a core member comprising a plurality of laminations arranged in a generally rectangular configuration. A spring spanning the core member is anchored at one end to the core at a point near the housing of the monitoring device and at the other end is attached to a bridging member affixed at the opposite end of the core near the housing. This allows the spring to expand less as it transverses the bridge in order to accommodate different power cable diameters.

Abstract: A fault indicator for indicating the occurrence of a fault current in an electrical conductor is mounted on the test point of an elbow connector of the type commonly used in power distribution systems. An integral collar assembly encircles the connector housing to capacitively couple the fault indicator circuitry to the system conductor within the connector. The collar assembly includes an inner magnetic core which establishes the coupling and an outer core which shields the inner core from magnetic fields resulting from fault currents in adjacent conductors.

Abstract: A fault indicator for use in conjunction with a load-break elbow connector includes a resilient mounting collar which wraps around the body of the fault indicator at a location overlying the arc-suppressing non-conductive margin between the electrically conductive sheath and the connecting end of the connector. An electrically conductive layer on the inside surface of the collar capacitively couples the circuitry of the fault indicator to the conductor within the connector to provide operating power to the fault indicator. A ground connection is provided by a second conductive layer on the collar which contacts the grounded connector sheath, or by a spring contact which extends from the fault indicator to the sheath. A voltage indicator is also disclosed using the same collar and capacitive coupling to the monitored conductor.

Abstract: A clamping mechanism for mounting a monitoring device to an electrical cable includes a core assembly formed by a plurality of laminations secured together and arranged in a generally rectangular configuration. A spring spanning the core is anchored at one end to the core at a point near the housing of the monitoring device and at the other end is attached to a bridging member affixed at the opposite end of the core near the housing. This allows the spring to expand less as it transverses the bridge in order to accommodate different power cable diameters.

Abstract: A fault indicator is described having a winding disposed on a magnetic pole assembly. The winding delivers energy from a monitored conductor to circuitry of the fault indicator. A series-connected threshold device, such as a four layer bilateral diode or a zener diode, precludes a capacitor from charging during normal current flow in the monitored conductor. The series-connected threshold device, however, breaks down when a fault current flows in the monitored conductor. After break down, the fault current charges the capacitor. A shunt-connected threshold device, such as a zener diode, limits the voltage developed across the capacitor. After its charging phase, the capacitor drives a multivibrator which actuates an LCD, displaying the occurrence of the fault current to an operator. A series-connected threshold device shuts the LCD off when the voltage across the capacitor drops to a sufficiently low level.

Abstract: A fault indicator is described which indicates the occurrence of a fault current in a monitored electrical conductor. The fault indicator includes a magnetic pole assembly which mounts the housing of the fault indicator to the monitored electrical conductor. The magnetic pole assembly includes both a main outer magnetic core assembly and an auxiliary inner magnetic core assembly. As described, an auxiliary fault sensing winding is disposed on the inner magnetic core assembly so that it becomes energized and provides power for fault circuitry within the fault indicator upon the occurrence of a fault current in the monitored electrical conductor. The fault circuitry positions a flag indicator within the module to visibly acknowledge the occurrence of the fault current in the electrical conductor.

Abstract: A fault indicator for indicating at local and remote locations the occurrence of a fault current in a conductor of an AC power distribution system utilizes a liquid crystal display having independent "F" and "N" optical display and shutter elements. Upon occurrence of a fault current a reed switch closes and a portion of the charge on a first capacitor is transferred to a second capacitor, which is connected to the "F" actuator electrodes of the liquid crystal display to cause an "F" to be displayed and an associated optical shutter to open. The "N" actuator electrodes are capacitively coupled to the monitored conductor and system ground to cause an "N" to be displayed and an associated optical shutter to open to indicate that voltage is present on the conductor. First and second light sources are caused to project through respective ones of the optical shutters onto respective first and second photodetectors.

Abstract: A voltage monitoring device for a three-phase ungrounded delta-connected power system utilizes liquid crystal optical shutter devices capacitively coupled between phases of the system such that the combined light transparency of the optical shutter devices varies with system phase-to-phase voltage. A light source projects a light beam through the optical shutter devices to a light detector such that the output of the light detector is dependent on the system voltage. A control circuit responsive to the output of the light detector provides a control signal when the system voltage falls outside of a predetermined operating range.

Abstract: A voltage monitoring device for an AC power distribution system utilizes a liquid crystal optical shutter device capacitively coupled between a conductor of the system and electrical ground such that the transparency of the optical shutter device to light varies with the system voltage level. A light source projects a light beam through the optical shutter device to a light detector such that the output of the light detector is dependent on the system voltage. A control circuit responsive to the output of the light detector provides an output signal when the system voltage falls outside of a predetermined operating range.

Abstract: A hot line indicator for instantaneously indicating the presence of voltage on an electrical conductor in an AC power distribution system includes a unitary one-piece housing having a projecting metallic probe and a hookeye for engaging a conventional lineman's hot stick. Within the housing, the display electrodes of a high impedance liquid crystal display component are coupled to the monitored conductor through the probe and a capacitive coupling to ground to provide an unambiguous "HL" display indicative of the presence of voltage on the conductor.

Abstract: A fault indicator for indicating the occurrence and relative direction of a fault current in a power transmission or distribution system includes a rotatably mounted indicator flag. The indicator flag is actuated 90.degree. clockwise or counterclockwise from a central reset position to up-line indicating or down-line indicating trip positions by a compact magnetic pole piece assembly having three radially extending magnetic pole segments which interact with four magnetic poles on a magnetic armature rotatably coupled to the indicator flag. A pair of magnetic windings magnetize the pole segments upon the occurrence of a fault current to rotate the flag from the reset position. A second pole piece and winding directionally actuated in response to the direction of the fault current determines the direction of rotation of the indicator flag to indicate whether the fault is upline or downline relative to the indicator.

Abstract: A housing and clamp assembly for mounting a circuit condition monitoring device on a monitored electrical cable includes a body member for housing device circuitry, a first relatively non-resilient clamp arm, and a second relatively resilient clamp arm. The clamp arms are biased closed around the conductor without pre-configuration of the clamp arms by parallel-spaced helical springs, which also serve to hold the cable against an indexing surface on the first clamp arm to minimize the effect of cable diameter on the spacing between the cable and the condition monitoring device and hence the calibration of the monitoring device.