Abstract: An apparatus and method for protecting against electrocution hazards that arise when an appliance is electrically connected to a miswired single-phase AC electrical source which includes an energized ground lead are described. The apparatus includes one or more sensors that detect electrical energy in the ground lead combined with a miswiring condition in the hot and common leads. A tester embodiment is also illustrated. The method includes the steps of detecting if the putative ground of the electrical source is energized and whether the hot and common leads are reversed.

Abstract: An alternating current contactor (AC contactor) with an electronic short circuit self-locking function, includes an AC contactor body (a). The AC contactor body (a) includes a shell body. A short circuit self-locking portion is provided inside the shell body. The short circuit self-locking portion includes a current collecting unit (b) for collecting a current signal of phase lines (A, B, C); a short circuit detecting unit (c) for obtaining a voltage signal which characterizes a current signal, comparing with a reference signal, and outputting a short circuit detecting signal when short circuit occurs; a short circuit self-locking executing unit (d) for obtaining the short circuit detecting signal to trigger the AC contactor body (a) to generate and maintain a circuit-breaking action; and a self-locking releasing unit (e) for releasing self-locking of the AC contactor body (a) and resetting the alternating current contactor body (a).

Abstract: A system, method, and apparatus for detecting wear in a screening arrangement is disclosed. The system, method, and apparatus can include a sensor that is configured to provide a notification signal when a surface of a screen panel has worn to a threshold level. The threshold level can be based at least in part on the amount of wear that requires replacement of a screen panel to prevent breakthrough or contamination. The notification signal provided by the sensor can be used to identify which screen panel or region of screen panels has been worn to the threshold level so that the screen panels can be replaced in a timely manner. The sensor may be coupled to a conductor embedded in one of the screen panels that is altered when a screen panel has worn to a threshold level, triggering the sensor to provide the notification signal.

Abstract: A three-phase faulted circuit indicator adjustable to accommodate a variety of three-phase power cables is disclosed. In one embodiment, faulted circuit indicator comprises a flexible holder that encircles the monitored conductor slightly more than one time. The flexible holder includes a plurality of magnetic sensors for monitoring the current within the internal conductors of the power cable, a logic circuit for determining the occurrence of a fault, and an output device for providing an indication of a fault. In a second embodiment, the faulted circuit indicator comprises a plurality of sensor compartments, each disposed about a central point, and each coupled to two other sensor compartments.

Abstract: Provided is a system, a tool and a method for communicating with a faulted circuit indicator (FCI), the faulted circuit indicator including a detection circuit for monitoring an electrical conductor of a power system. The system includes a display and a first light emitting diode associated with the display. The first light emitting diode generates an optical FCI status signal in response to an occurrence of a fault in the electrical conductor. The system also includes a first microcontroller operatively coupled to the display and the detection circuit, and a handheld user command tool adapted to optically signal the display. The handheld user command tool may be also adapted to generate an optical serial communication. The optical serial communication may provide data and/or commands for operation of the faulted circuit indicator. The display may be integrated into the FCI. The FCI may be an overhead FCI.

Abstract: A power supply protection device for an electric appliance includes a switching circuit for establishing an electrical connection to receive an external voltage from the external power supply and output the external voltage to the electric appliance, a detecting circuit for disabling the switch circuit to break the electrical connection when determining the external voltage is equal to or higher than a predetermined value, and an alert circuit for generating an alert signal when the electrical connection is broken and outputting the alert signal to a user.

Abstract: A monitoring device for an ungrounded electric network of a photovoltaic system. The monitoring device includes a short circuit measuring circuit having a first electric measuring circuit conductor connecting a first electric pole of the photovoltaic system with a reference point by means of at least one protective component, and second electric measuring circuit conductor for connecting a second electric pole of the photovoltaic system with ground be means of at least one protective component. A first component is connected between one of the measuring circuit conductors and ground, and a measuring device for measuring an electric parameter of the first component, wherein a non-zero value of the parameter and/or a change of the value of the parameter indicate an electric fault between the photovoltaic system and ground.

Abstract: An electrical tripping mechanism for protecting an electrical device from mechanical and over temperature problems. The tripping mechanism includes a copper conductor encased within an insulative layer, where the insulative layer is provided with a helically wound metallic strip amenable to easy tearing when subjected to mechanical damage. When the continuity of the strip is broken, a sensor detects the damage and shuts-down the electrical device.

Abstract: An arc fault detector includes a means for repeatedly measuring an elapsed time. The arc fault detector also includes at least one means to perform arc detection at each repeated elapsed time. Means for initiating a tripping mechanism is activated after the elapsed time. When a fault occurs, means for generating at least one fault code is activated. The fault code is stored in at least one non-volatile memory. The fault code is selected from a group consisting of an arc fault interrupt code, a ground fault interrupt code, and a push-to-test interrupt code. The arc fault detector includes at least one means to display the fault code such as at least one LED. At least a first LED indicates an arc fault interrupt code and at least a second LED indicates a ground fault interrupt code. At least a third LED indicates a push-to-test interrupt code.

Abstract: The invention comprises a set of methods to detect the resistance of a connection to safety ground and to detect the presence of voltage hazardous to people in systems where an unknown amount of current intermittently flows in the safety ground circuit. Samples of voltage between two points in the safety ground circuit are taken repeatedly. When the voltage caused by the unknown currents in the safety ground circuit is below a preset threshold, a known current is applied and another voltage sample is taken to detect the electrical resistance of the safety ground circuit. If an excessive resistance or voltage is detected, one or more outputs are activated or deactivated to indicate the problem and remove power from the system. The invention requires no current sensor for its operation.

Abstract: A controller suitable for identifying an abnormal operational condition in a bathing system is provided. The controller includes a memory unit adapted for storing measurements indicative of electrical currents drawn by the bathing system under normal operating conditions, each measurement being indicative of the electrical current being drawn by a respective bathing unit component in the bathing system. The controller also includes a processing unit for modifying the measurements stored in the memory unit and for detecting an abnormal operational condition associated with the bathing system at least in part on the basis of measurements stored on the memory unit. In specific implementations, sensing circuitry adapted for obtaining measurements associated to components, such as relays and fuses, is provided.

Abstract: Proper insertion of medical leads into medical devices is detected at the time the lead is being inserted. An external device initiates impedance testing by the medical device that is receiving the lead prior to the insertion of the lead being completed. The medical device reports back the results of the impedance testing so that the external device can determine whether the lead is properly inserted at the time of lead insertion and can provide an output to a user to indicate whether the lead insertion is proper. The medical device may poll only a last connector expected to be connected before responding, test other connector combinations before or after responding, and so forth.

Abstract: A wireless electrically isolated plug-n-play communications system for branch circuit breakers. The system providing means for automatically connecting the wireless electrically isolated communication system between the branch circuit breaker and a communications strip as the branch circuit breaker is being installed in the load center.

Abstract: A portable bearing test device includes a power supply that is operable to supply direct current (DC) electrical power via a plurality of power supply outputs and a circuit common. Independent bearing test circuits are coupled to receive output electrical power from one of the power supply outputs, and are further adapted to independently couple to a separate rotating machine test bearing. Separate indicator lights are electrically coupled in series in each of the independent bearing test circuits.

Abstract: A system, method, and apparatus for detecting wear in a screening arrangement is disclosed. The system, method, and apparatus can include a sensor that is configured to provide a notification signal when a surface of a screen panel has worn to a threshold level. The threshold level can be based at least in part on the amount of wear that requires replacement of a screen panel to prevent breakthrough or contamination. The notification signal provided by the sensor can be used to identify which screen panel or region of screen panels has been worn to the threshold level so that the screen panels can be replaced in a timely manner. The sensor may be coupled to a conductor embedded in one of the screen panels that is altered when a screen panel has worn to a threshold level, triggering the sensor to provide the notification signal.

Abstract: A signaling device for electrical monitoring devices, in particular for short circuit and/or ground fault indicators, and for optical, visually perceptible signaling with at least one luminous element is provided. The signaling device has a housing having a housing wall and a region formed in the housing wall so as to cover the luminous element. A printed circuit board is disposed in the housing. The luminous element is arranged within the housing and directly on the printed circuit board. The housing wall is formed such that it is at least light-transmissive in the region.

Abstract: An apparatus, system, and method are disclosed for detecting the formation of a short between a magnetoresistive (“MR”) head and a head substrate. The apparatus is presented with a logic unit containing a plurality of modules configured to functionally execute the necessary steps of generating a baseline electric potential level between a head substrate and ground, monitoring the level of the electric potential between the head substrate and ground, and detecting the formation of a short circuit between the MR head and the head substrate by detecting a change in the electric potential level monitored by the monitoring module from the baseline level to a predetermined threshold level. Beneficially, such an apparatus, system, and method would reduce read errors on the magnetic tape storage system, the time and resources required to recover from such errors, and allow for preventative measures to obviate contamination short related failures of tape drive systems.

Abstract: A constant current source, a measurement unit, an indication unit, and a controller are provided. The constant current source is connected to a shell of an electric device and configured to supply a constant current to the shell. The shell is connected to a ground line terminal of a power supply to which the electric device is connected. The measurement unit is configured for measuring a first voltage of the ground line terminal and a voltage between the shell and the ground line terminal. The controller is configured for controlling the indication unit to give warnings either when the first voltage is zero or when the second voltage is higher than a preset value.

Abstract: An apparatus and method for a supervisory circuit for a ground fault detection device or ground fault circuit interrupt (GFCI) device is disclosed in which is a test stimulus signal for a self test of the GFCI device is generated on a second secondary winding on a toroid of a differential current transformer. The GFCI device includes line and neutral conductors configured to connect an AC power source and a load. A differential current transformer includes a toroid, through which the line and neutral conductors pass, a first secondary winding wound on the toroid to generate a current in response to an imbalance of magnetic flux in the toroid, and a second secondary winding wound on the toroid. A differential ground fault detector is electrically connected to the first secondary winding of the differential current transformer to compare current generated in the secondary winding to a trip threshold.

Abstract: An ungrounded electrical power distribution system may experience a single line to ground fault. Such a fault may not disrupt operation of the system, but its presence may raise a risk of additional problems if left uncorrected. A system for progressively grounding the ungrounded system may be initiated when a line to ground fault is suspected. As grounding through successively lower impedance proceeds, fault current may increase and detection of severity of the line to ground fault may be more readily achieved, thus facilitating localization of the fault.

Abstract: A detection and alarm circuit includes a transformer, a rectifier, and an alarm. A first input terminal of the transformer is connected to a ground terminal of an electronic device, and a second terminal of the transformer is grounded. A first output terminal of the transformer is connected to a first input terminal of the rectifier, and a second output terminal of the transformer is connected to a second input terminal of the rectifier. A first output terminal of the rectifier is connected to a first terminal of the alarm. A second output terminal of the rectifier is connected to a second terminal of the alarm.

Abstract: A controller suitable for identifying an abnormal operational condition in a bathing system is provided. The controller includes a memory unit adapted for storing measurements indicative of electrical currents drawn by the bathing system under normal operating conditions, each measurement being indicative of the electrical current being drawn by a respective bathing unit component in the bathing system. The controller also includes a processing unit for modifying the measurements stored in the memory unit and for detecting an abnormal operational condition associated with the bathing system at least in part on the basis of measurements stored on the memory unit.

Abstract: In one embodiment, the present invention is a method and apparatus for ground fault detection. One embodiment of a method for diagnosing a ground fault in a notification appliance circuit comprising a plurality of field wiring connections includes individually testing each of the plurality of field wiring connections until a source of the ground fault is detected and outputting a signal identifying the source of the ground fault.

Abstract: An object is to provide a display device, in a part of which a monitor light emitting element is provided and in which an anode and a cathode of the monitor light emitting element are prevented from short-circuiting in an early stage and over time by using a circuit which corrects a voltage or a current to be supplied to a light emitting element in consideration of electrical property fluctuation of the monitor light emitting element, and a method for inspecting the display device. A monitor light emitting element is provided, which is electrically connected to a monitor line for supplying a current is provided, and a circuit is provided, which electrically disconnects the monitor light emitting element when an anode and a cathode of the monitor light emitting element are short-circuited in an early stage or over time. Further, a circuit for checking circuit operation before or after a step of providing the monitor light emitting element is provided.

Abstract: A method and system for monitoring latent faults in power supplies may include a variable voltage source and a logic module that may be coupled to an OR FET circuit. The monitoring system may also include comparators for measuring a voltage drop across a FET and, based upon a value of the voltage drop, may determine a latent fault, such as a short circuit or open circuit across the FET.

Abstract: According to one embodiment, an electronic device, includes: a short-circuit mechanism configured to be provided with a potential difference between a first conductor and a second conductor, the first conductor and the second conductor being disposed on an insulator, the second conductor being disposed on the insulator apart from the first conductor by a predetermined clearance; a measuring module configured to measure, when the electronic device is activated, an electrical value between the first conductor and the second conductor; a detector configured to detect, when the electrical value is a preliminarily set electrical value, a short-circuit between the first conductor and the second conductor; a notifying module configured to notify, when the short circuit is detected, occurrence of the short-circuit; and an activation module configured to selectably activate or deactivate the electronic device when the short circuit is notified.

Abstract: System and method for detecting partial discharge arcing phenomena in a power network distribution system which employs a mobile receiving assemblage including a wideband antenna, a computer controllable wideband radio receiver deriving an amplitude detected output and a global positioning system providing system position data. The amplitude detected outputs are digitized and treated with a digital signal processor based analysis including fast Fourier transforms extracting narrowband signal frequencies that are harmonically related to the network fundamental frequency. The narrowband signal frequencies are analyzed for peak amplitudes which are summed to derive maintenance merit values related to the arcing phenomena.

Abstract: Various electrical apparatuses which include a current dampening device are disclosed. In one embodiment, an electrical apparatus is provided which includes a motor and a switch having an “on” position and an “off” position to control the operation of the motor. A current dampening device is connected in parallel with the motor downstream from the switch to dampen transient current. In another embodiment a ground fault circuit interrupter (GFCI) is electrically connected to the motor upstream from the switch.

Abstract: A power equipment includes a first internal abnormality detection apparatus comprising a first antenna accommodation pipe which is connected to a first connection pipe formed in a enclosed container and which accommodates a first antenna therein, and a first signal detection circuit which is connected to a first antenna and which detects an electromagnetic wave signal emitted when any abnormality has occurred within the enclosed container.

Abstract: Computer systems and techniques for predicting a cable failure in a network system begin by receiving a remote alarm indicator followed by a remote alarm indicator clear as a transmission alarm indicator of an intermittent short duration failure on the transmission path of a circuit. If the transmission alarm indicator is of a duration less than or equal to a preset threshold D it is considered an acceptable short hit transmission alarm. When at least N acceptable transmission alarms have been received and the time stamps of the last N acceptable transmission alarms have been recorded, then a determination is made as to whether N acceptable transmission alarms have been received within a preset time period. A moving window time period is calculated as the difference between the time stamp of the present acceptable transmission alarm K and the time stamp of the [(K?N)+1] acceptable transmission alarm. If the difference is less than or equal to T, a cable error signature is indicated.

Abstract: A power supply controller includes a semiconductor switching element disposed on a current supply line from a power source to a load. The semiconductor switching element is switched between ON and OFF for controlling power supply to the load. A short anomaly of the semiconductor switching element is determined if at least one of an input-to-output voltage of the semiconductor switching element being smaller than a first threshold and the semiconductor switching element being in an ON state is detected, when an OFF signal for instruction to turn OFF the semiconductor switching element is received.

Abstract: A controller suitable for identifying an abnormal operational condition in a bathing system is provided. The controller includes a memory unit adapted for storing measurements indicative of electrical currents drawn by the bathing system under normal operating conditions, each measurement being indicative of the electrical current being drawn by a respective bathing unit component in the bathing system. The controller also includes a processing unit for modifying the measurements stored in the memory unit and for detecting an abnormal operational condition associated with the bathing system at least in part on the basis of measurements stored on the memory unit. In specific implementations, sensing circuitry adapted for obtaining measurements associated to components, such as relays and fuses, is provided.

Abstract: It is judged whether the abnormal current is due to the electric leakage or not by a detection step detecting the abnormal current by the leakage current detection board and comparing a threshold value of predetermined items stored in a storing unit and actual values corresponding to the items at the time of when a compressor is stopped by detecting the abnormal current in the detection step. Specifically, the abnormal current is recognized as the electric leakage to be displayed on a display unit when at least one of the operating time at the time of detecting the abnormal current, the inner pressure of a motor, and a discharge pipe temperature is lower than the corresponding threshold value.

Abstract: A monitoring system for detecting earth faults in an electrical power supply grid providing a power signal includes a plurality of monitoring devices, each of the monitoring devices including a detector for detecting the level of harmonics in the power signal, wherein the level of harmonics is detected in a specific frequency range. Each of the monitoring devices further includes a memory for storing a harmonics reference value, a processor for comparing the detected level of harmonics with the reference level, and a communication device for transmitting an alarm if the detected level of harmonics is above the reference level for a specific period of time. Each of the detectors includes an optical sensor for detecting the harmonics by use of the Faraday effect.

Abstract: A method is disclosed for detecting a discontinuity or irregularity in a supply line of an electrical power distribution network including a neutral return line and an earth return line. The method includes measuring a property associated with the supply line wherein the property is different when the network includes the neutral return line compared to when the network does not include the neutral return line. The method also includes comparing a result of the measuring with a reference to provide an indication of the discontinuity or irregularity. The property may include a complex impedance associated with the neutral return line or earth return line and/or ambient electrical noise present on the supply line. An apparatus for detecting a discontinuity or irregularity in a supply line of an electrical power distribution network is also disclosed.

Abstract: A galvanic ground isolator adapter protects against galvanic corrosion on a boat when a boat power system is connected to a shore power system. A ground isolation assembly in the ground connection between the two system grounds prevents current from passing between the two system grounds when the voltage difference between the two is low. When the voltage difference exceeds a preset value, the ground connection is established. The adapter is entirely contained within a rigid housing with a male plug at one end and a female socket at the other end. In this form it can be simply connected to a power cord that is normally used in connecting the shore and boat power systems. It may be provided with a locking mechanism that prevents it being removed once it is attached. It may be supplied with a sonic alarm to indicate when current is flowing in the ground connection.

Abstract: Systems and methods for detecting ground fault at the common DC bus in a high impedance ground system. A fault detection component can detect characteristics of an electrical signal including phase number (n) and fundamental frequency (H). A fast Fourier transform is performed at (n×H) and (2n×H), and the two values are compared. A healthy system (no ground fault) can display a large difference between (n×H) and (2n×H), while in an unhealthy system the difference can be minimal. A system and method of detecting variable phase number and fundamental frequency can be used in the calculation to perform the ground fault detection when these characteristics are variable.

Abstract: Provided is a system, a tool and a method for communicating with a faulted circuit indicator (FCI), the faulted circuit indicator including a detection circuit for monitoring an electrical conductor of a power system. The system includes a display and a first light emitting diode associated with the display. The first light emitting diode generates an optical FCI status signal in response to an occurrence of a fault in the electrical conductor. The system also includes a first microcontroller operatively coupled to the display and the detection circuit, and a handheld user command tool adapted to optically couple with the display. The handheld user command tool is also adapted to generate an optical serial communication. The optical serial communication provides data and commands for operation of the faulted circuit indicator. The display may be remote or integrated into the FCI.

Abstract: A detection and alarm circuit includes a transformer, a rectifier, and an alarm. A first input terminal of the transformer is connected to a ground terminal of an electronic device, and a second terminal of the transformer is grounded. A first output terminal of the transformer is connected to a first input terminal of the rectifier, and a second output terminal of the transformer is connected to a second input terminal of the rectifier. A first output terminal of the rectifier is connected to a first terminal of the alarm. A second output terminal of the rectifier is connected to a second terminal of the alarm.

Abstract: A method for detecting operations of a power storage device is disclosed. The power storage device includes an electricity storage unit for storing power output from an electronic device or outputting power to the electronic device. The method includes detecting current between the electricity storage unit and the electronic device to determine whether the electricity storage unit is malfunctioned and causes short circuit, and generating an alarm signal when the electricity storage unit is malfunctioned and causes short circuit.

Abstract: A current monitoring device (CMD) with a set of electromagnetic field sensors located within one or more grounded housings positioned within the combined electromagnetic fields generated by one or more electric power lines. The CMD includes electronics, typically located within the grounded housings, defining impedance networks that combine the measurements received from the field sensors to create output signal indicative of electric current values for the phase conductors. The housings can be conveniently attached and to transmission line towers, distribution line poles, and high voltage power line supports in transmission and distribution substations. The CMD controls response equipment, such as a circuit interrupter that responds to current disturbances detected by the CMD. The CMD may also include communication for sending the current values to a remote controller, such as a central control station, that implements a wide range of response equipment.

Abstract: A monitoring system for detecting earth faults in an electrical power supply grid providing a power signal includes a plurality of monitoring devices, each of the monitoring devices including a detector for detecting the level of harmonics in the power signal, wherein the level of harmonics is detected in a specific frequency range. Each of the monitoring devices further includes a memory for storing a harmonics reference value, a processor for comparing the detected level of harmonics with the reference level, and a communication device for transmitting an alarm if the detected level of harmonics is above the reference level for a specific period of time. Each of the detectors includes an optical sensor for detecting the harmonics by use of the Faraday effect.

Abstract: In one embodiment, the present invention is a method and apparatus for ground fault detection. One embodiment of a method for diagnosing a ground fault in a notification appliance circuit comprising a plurality of field wiring connections includes individually testing each of the plurality of field wiring connections until a source of the ground fault is detected and outputting a signal identifying the source of the ground fault.

Abstract: Apparatus includes an arc wave generator for testing an arc fault circuit interrupter (AFCI) for use in a test system for testing whether or not an arc fault circuit interrupter (AFCI) is operating normally, in which a false arc is generated for use in testing the arc fault circuit interrupter (AFCI). The arc wave generator includes a rectifier which receives a commercial power source as an input source and rectifies alternating-current voltage of the commercial power source to generate a rectified signal. A drop resistor drops the voltage of the rectified signal to generate a voltage-dropped signal. A mono-stable multivibrator adjusts a voltage level and a pulse width of the voltage-dropped signal and generates a pulse signal which is used to generate a false arc for testing the arc fault circuit interrupter (AFCI). Thus, a false arc is generated with a simple circuit to accurately test the actions of the arc fault circuit interrupter (AFCI).

Abstract: A signal injection unit injects a test signal at a main frequency between a reference point of an electric circuit and ground, where the electric circuit is connected with the facility and injects another test signal at a second main frequency between a reference point of the electric circuit and ground. A signal conversion unit measures first and second response voltages and first and second response currents in the electric circuit, where the response voltages and the response currents result from the test signals. A processing device determines impedances to ground of the facility from the response voltages and the response currents, analyses impedances to ground of the facility, where this analysing includes comparing each determined impedance to ground with a predetermined value, and determines a safety state of the disconnected electrical facility based on the analysed impedances to ground.

Abstract: An information request portion receives an information request signal transmitted to an information response portion at its own receiving port. The information request portion comprises at least either a power supply system anomaly determination portion or a ground anomaly determination portion. The power supply system anomaly determination portion determines a short-circuit between a signal line and a power supply system in a case where the information request signal received at the receiving port is always fixed to a H (high) level. The ground anomaly determination portion determines a short-circuit between a signal line and a ground in a case where the information request signal received at the receiving port is always fixed to a L (Low) level. Consequently, the anomaly region of the signal line connects the information request portion and the information response portion so that bidirectional digital communications are possible or the cause of the anomaly is specified.

Abstract: An arc fault and/or ground fault circuit interrupter includes an operating mechanism structured to open and close separable contacts, a trip mechanism cooperating with the operating mechanism to trip open the separable contacts, a test button structured to test the operating mechanism, an indicator, and a controller structured to configure a setting of the circuit interrupter and operate the indicator to indicate the setting in response to an actuation of the test button.

Abstract: A generator monitoring system and method includes a plurality of sensors (12) disposed within a generator enclosure (18) to sense health conditions of a generator (10) housed within the enclosure. The sensors are interconnected to provide a single communication path (14) for allowing communication with the plurality of sensors. A monitoring device (16) outside the generator enclosure receives health condition information from each of the plurality of sensors via the single communication path. A sensor may be disposed within the generator enclosure to detect particulates emitted from a monitored portion (e.g., 52) of the generator housed within the enclosure. A sensor may be disposed proximate a bus bar connection (130) of the generator to sense a health condition of the bus bar connection and generate corresponding health condition information provided to the monitoring device.

Abstract: An information request portion receives an information request signal transmitted to an information response portion at its own receiving port. The information request portion comprises at least either of a power supply system anomaly determination portion or a ground anomaly determination portion. The power supply system anomaly determination portion determines a short-circuit between a signal line and a power supply system in a case where the information request signal received at the receiving port is always fixed to a H (high) level. The ground anomaly determination portion determines a short-circuit between a signal line and a ground in a case where the information request signal received at the receiving port is always fixed to a L (Low) level. Consequently, the anomaly region of the signal line connecting the information request portion and the information response portion in such a manner that bidirectional digital communications are possible or the cause of the anomaly is specified.

Abstract: A three-phase faulted circuit indicator adjustable to accommodate a variety of three-phase power cables is disclosed. In one embodiment, faulted circuit indicator comprises a flexible holder that encircles the monitored conductor slightly more than one time. The flexible holder includes a plurality of magnetic sensors for monitoring the current within the internal conductors of the power cable, a logic circuit for determining the occurrence of a fault, and an output device for providing an indication of a fault. In a second embodiment, the faulted circuit indicator comprises a plurality of sensor compartments, each disposed about a central point, and each coupled to two other sensor compartments.