Abstract: Systems and methods that measure electrical parameters of a multi-phase electrical system may utilize a multi-phase measurement device that includes a sensor subsystem that has a voltage sensor and a current sensor. Each of the voltage sensor and the current sensor may be a contact-type sensor or a “non-contact” sensor that does not require galvanic contact. In operation, a multi-phase measurement device may utilize the voltage sensor and the current sensor to sequentially obtain single phase measurements for each phase of a multi-phase electrical system. The measurements may be synchronized to obtain various multi-phase power parameters, such as various parameters relating to power, phase, voltage, current, etc. The multi-phase measurement device may be operative to automatically detect when an operator has positioned a sensor of the sensor subsystem proximate a conductor under test so the multi-phase measurement device can initiate detection of one or more electrical parameters in the conductor.

Abstract: A method and a device for cleaning an electric cable and/or an electric insulator connected to the electric cable. The device includes a power supply module operative to extract electric power from magnetic field surrounding an electric cable, a propulsion module for maneuvering the device at least one of along the electric cable and around the cable, and a dusting module for cleaning the electric cable, where the device is mounted on a single electric cable of an electric transmission grid and/or an electric distribution grid.

Abstract: A method includes measuring an impedance of a shunt as a function of frequency and converting the impedance to an admittance in a time domain. The method further includes connecting the shunt in a circuit and measuring voltage data across the shunt over a predetermined interval. The method includes outputting a signal indicative of a current through the shunt derived from the voltage data convolved with the admittance. The method may be implemented in a controller configured to interface with the shunt.

Abstract: An accessory device for low or medium voltage electric applications includes a casing and electronic means including one or more current sensors for detecting current flowing in an electric cable. The top shell of the casing includes an external recess having a cable seat for accommodating the electric cable in a transversal position with respect to the casing. The cable seat has a cable coupling surface adapted to mechanically couple with the electrical cable. The accessory device includes a holder element mechanically coupleable with the top shell in the external recess. The holder element includes one or more holding surfaces. Each of the holding surfaces is overlapped and mechanically coupled with the electric cable, when the holder element is positioned in the external recess in a corresponding accommodating position that is selectable depending on the size of the electric cable.

Abstract: A system for detecting and indicating partial discharges and voltage. The system allows capturing signals from the electric power system and/or the electrical equipment thereof, and detecting and indicating the presence or absence of partial discharges and voltage, which allows carrying out a quick and simple inspection in order to prevent faults in the distribution elements, preventing risks and performing suitable installation maintenance.

Abstract: Power distribution networks need to monitor the electrical power at points around the network. A unit which senses the electrical characteristics of the network can also sense other environmental characteristics of the electrical network at that location. An electrical sensor unit attachable to an insulated electrical distribution cable comprises at least one electrical sensor for at least one of current, voltage, and phase angle of electrical power being transmitted in the cable, a source of electrical power for driving the electrical sensors, and a socket for receiving an environmental sensor and comprising connections for the source of electrical power. The unit comprises an annular body defining an axial passage through which an electrical conductor can pass, the annular body housing an electrical sensor in the form of a current sensor including a loop extending around the axial passage.

Abstract: Disclosed is a system for charge-discharge cycler, particularly to a system for charge-discharge cycler in which a structure of a shunt is improved to improve performance/accuracy of a current control as a key component of an instrument for testing a secondary battery charge-discharge. A system for charge-discharge cycler has the effect of improving the degree of precision/performance of the current control during a charge/discharge inspection of the secondary battery, thereby raising the standard of development/aspect of the secondary battery and developing a charge/discharge performance tester of high performance.

Abstract: The present invention relates to an apparatus for calibrating a power measuring system for power transformers. The general inventive concept involves the two reference measuring systems that are known from the prior art for the calibration of a current transformer, a voltage transformer and an evaluation device being integrated in a shared apparatus, according to the invention, for calibrating a power measuring system for power transformers, which apparatus is furthermore arranged on a container such that the apparatus can be moved by means of a trailer that holds the container for the purpose of in-situ calibration of the power measuring system of power transformers.

Abstract: A temperature sensing system including a head unit comprising a thermal sensor for acquiring thermal data from a surface, a wireless transmitter wirelessly transmitting the thermal data, and a mounting interface; and a non-conductive pole connected to the mounting interface of the head unit.

Abstract: A monitoring device (10) includes a feature amount storage unit (11) that stores a device feature amount which is a feature amount of each of a plurality of electrical devices installed in a predetermined unit in operation; a measured data acquisition unit (12) that acquires measured data of the predetermined unit which is at least one of a total current consumption, a total power consumption, and a voltage measured in the predetermined unit; a feature amount extraction unit (13) that acquires a measurement feature amount which is the feature amount included in the measured data of the predetermined unit; a correction unit (15) that corrects a first feature amount which is the device feature amount or the measurement feature amount based on unit feature information indicating a feature of the predetermined unit; and a presumption unit (16) that presumes the electrical device being in operation using the corrected first feature amount, and a second feature amount which is the device feature amount or the measu

Abstract: The present invention may be embodied in an in-line high voltage electric power line monitor including a DC current sensor, an AC current sensor, a voltage sensor, an energy harvesting power supply, and a communication device configured. The in-line power line monitor includes a bus bar that connects in series with the monitored power line. For example, the in-line power line monitor may be connected at the junction point between the monitored power line and a support structure, such a sectionalizing switch that supports the monitor positioned between the switch and the power line. A pair of DC current measurement pickups are spaced apart on the bus bar and operatively connected to the microprocessor. The in-line power line monitor also includes an AC current sensor coil and an energy harvesting device (e.g., inductive coil) that surround the bus bar. The AC current sensor coil, the power supply coil and the voltage sensor positioned adjacent to, but spaced apart from, the bus bar.

Abstract: A sensor to monitor health of surge arresters such as metal oxide arresters is disclosed. The sensor includes a housing; a sensor assembly contained in the housing, the sensor assembly including an electronics board to receive, transmit, process, and store signals; and a voltage measurement strap extending around a periphery of the housing, the voltage measurement strap being electrically connected to the electronics board and configured to measure voltage using electric field.

Abstract: A seat-occupancy and occupant-class detector for a vehicle seat having a back part and a seat part has an insulated but conductive surface element mounted on the seat part of the vehicle seat roughly parallel to a seat cushion thereof. A signal generator feeds an electrical measuring signal to the surface element, and first and second receiving electrodes are provided in the backrest at different spacings from the surface element but vertically level with each other such that the measuring signal of the surface element induces different voltages in the receiving electrodes. Calculation and evaluation steps performed in an evaluation unit take as their basis a value that is a quotient of different measurements for the same physical size and is therefore dimensionless. The reason for this is the arrangement of the two receiving electrodes at a different spacing from the conductive surface element on the seat cushion side.

Abstract: There is provided a ring-shaped magnetic core that forms a closed magnetic circuit that encloses a measured electrical path, a magneto-electric converter that detects magnetic flux inside the magnetic core and outputs an electrical signal with an amplitude in keeping with a quantity of the magnetic flux, a coil that is formed on the magnetic core and is supplied with a negative feedback current generated based on the electrical signal, and an internal shield member disposed at least in a vicinity of the magneto-electric converter and the coil. A first gap that increases a magnetoresistance of a closed magnetic circuit, which is a closed magnetic circuit for leakage flux that leaks from the magnetic core and includes the internal shield member, a part of the magnetic core where the coil is formed, and the magneto-electric converter, is formed in the internal shield member.

Abstract: A current sensor includes a bus bar through which an electric current to be measured flows, a first magnetic sensing element including a first magneto-sensitive portion including a magneto-resistive element, and a second magnetic sensing element including a second magneto-sensitive portion including a magneto-resistive element. Strength of a magnetic field generated by the electric current sensed by the first magneto-sensitive portion is different from a strength of the magnetic field sensed by the second magneto-sensitive portion. A first bias magnetic field is applied to the first magneto-sensitive portion and a second bias magnetic field in a direction opposite to a direction of the first bias magnetic field is applied to the second magneto-sensitive portion.

Abstract: A power module includes an input bus, a switching device, and an output bus. The input bus includes a first coating of a high permeability magnetic conductive material and is configured to receive input direct current (DC) electrical power from an electrical power source. The switching device is electrically coupled to the first input bus, and is configured to selectively connect and disconnect to facilitate converting the input DC electrical power into output alternating current (AC) electrical power. The output bus includes a second coating of the high permeability magnetic conductive material, and is electrically coupled to the first switching device. The output bus is configured to supply the output AC electrical power to an electrical load.

Abstract: A power converter for driving a three-phase AC motor with three phase conductors has: a first terminal for connecting a first of the three phase conductors of the three-phase AC motor, wherein a current which is to be output by way of the first terminal is routed to the first terminal by way of an electrical feed line, and a ground-fault and/or short-circuit identification circuit which is designed to detect a ground fault and/or short circuit of the first terminal. The ground-fault and/or short-circuit identification circuit has: a coil with a winding which is arranged adjacent to the electrical feed line, wherein the winding does not surround the electrical feed line, and an evaluation device which is designed to evaluate a voltage, which is induced in the winding, for ground-fault and/or short-circuit identification.

Abstract: A system (100) for monitoring a temperature of an electrical conductor of an electrical cable and including a temperature sensor unit (100a) and a transceiver unit (100b). The temperature sensor unit (100a) is located inside the first (semi)conductive layer and includes a micro-controller (120), a temperature sensor (110), an energy harvest sub-unit (140) and a wireless transmitter layer (130). The temperature sensor (110) is adapted to detect a first signal (S1) representing temperature of the electrical conductor and to supply the first signal (S1) to the micro-controller (120). The transceiver unit (100b) is located outside the first (semi)conductive layer and includes an energy transmitter (160) and a wireless receiver (150). The energy harvest sub-unit (140) is adapted to harvest electromagnetic power from the energy transmitter (160) and to provide electrical power to the micro-controller (120).

Abstract: A multifunctional high current circuit board includes a high current-carrying current-conducting layer and a switching layer, which is connected to at least one heat source, wherein high current-carrying potentials are conducted into the switching layer.

Abstract: The present disclosure pertains to systems and methods for detecting traveling waves in electric power delivery systems. In one embodiment, a system comprises a capacitance-coupled voltage transformer (CCVT) in an electric power delivery system, the CCVT comprising a first capacitor disposed between an electrical bus and a first electrical node, and a second capacitor electrically disposed between the first electrical node and a ground connection. A resistive divider in electrical communication with a first node may generate a resistive divider electrical signal corresponding to a voltage value. An intelligent electronic device (IED) in electrical communication with the resistive divider monitors a resistive divider voltage signal. The IED detects a traveling wave based on the resistive divider voltage signal and a measurement of a primary current through an electrical bus in electrical communication with the CCVT; and analyzes the traveling wave to detect a fault on the electric power delivery system.

Abstract: A current detection device includes plural bus bars, plural magnetic detection elements that are arranged respectively corresponding to the bus bars, a magnetic shield arranged to surround parts of the bus bars and the magnetic detection elements, a correction factor calculation unit that, on the basis of voltages output from the magnetic detection elements when any two or more of the bus bars are supplied with inversely phased currents, calculates correction factors for correcting mutual interference between the magnetic detection elements, a recording medium that holds the correction factors calculated by the correction factor calculation unit, and a current calculation unit that, using the correction factors held in the recording medium, calculates the currents flowing through the bus bars on the basis of the voltages output from the magnetic detection elements.

Abstract: A method and apparatus for earth fault in power high and/or medium voltage system may enhance a protection system for special technical task, which is to measure residual current, the invention is, that for earth fault protection in power system or a part of power system, for example, but not limited to, cable connectors, wherein residual current is determined indirectly by the calculation from the phase current values, obtained from the output signals of Rogowski-coil based current sensors.

Abstract: Current sensors, systems and methods are provided. A test current is injected via a pair of force terminals into a conductor and a pair of sense terminals are configured to provide an input signal that corresponds to a voltage drop across the conductor. Based on the test current in the conductor and based on the input signal, a contribution to the voltage drop due to the test current and a contribution to the voltage drop due to a primary current through the conductor may be determined. In addition, at least one of a reference resistance of the conductor and the primary current in the conductor may be further determined.

Abstract: A coil that includes a coupled mobile device.

Abstract: A current sensor for use with a charged device model (CDM) tester includes an outer conductor and a cylindrical inner conductor. The inner conductor is positioned within a central cylindrical bore of the outer conductor to provide a characteristic transmission line impedance of approximately 50 ohms. A test probe conductor extends from the distal end of the inner conductor and is electrically connected to the inner conductor. An array of self-supporting ceramic chip resistors is radially positioned between the distal ends of the inner conductor and the outer conductor to provide a uniformly distributed resistance between the inner conductor and the outer conductor. When the test probe conductor is applied to a pin of a charged device under test (DUT), a discharge current passes through the resistors and produces a voltage on the inner conductor that is provided as a signal voltage proportional to the discharge current.

Abstract: In one aspect, a magnetic field sensor includes a chopper stabilized amplifier and a plurality of Hall-type elements in parallel and connected to the chopper stabilized amplifier. In another aspect, a magnetic field sensor includes a chopper stabilized amplifier and a plurality of Hall quad elements in parallel and connected to the chopper stabilized amplifier. In a further aspect, a current sensor has a bandwidth of 1 MHz and includes a chopper stabilized amplifier and a plurality of Hall quad elements, fabricated in silicon, in parallel and connected to the chopper stabilized amplifier.

Abstract: There is provided a non-contact voltage measurement device which can precisely measure a measurement target voltage by suppressing a flow of a leakage current via a parasitic capacitance produced between an electric field shield and an electric circuit. A drive voltage applying unit applies a voltage generated from an output voltage of a low impedance unit of the electric circuit and equal to an input voltage of a high impedance unit, to a first electric field shield coated on the high impedance unit.

Abstract: Voltage sensor (1) for a high- or medium-voltage power-carrying conductor for a power network, such as an inner conductor of a power cable or a cable connector or a bus bar. The voltage sensor has a tubular shape and an axial passageway (40), which can receive the conductor. The voltage sensing device comprises a) a radially-inner electrode (20), operable as a first sensing electrode of a sensing capacitor for sensing the voltage of the power-carrying conductor, b) a radially-outer electrode (30), operable as a second sensing electrode of the sensing capacitor, and c) a solid carrier element (10), at least a first portion of which is arranged between the inner electrode and the outer electrode, the first portion being operable as a dielectric of the sensing capacitor. The sensor can be accommodated in a cable accessory. The carrier element may comprise ceramic material to increase accuracy.

Abstract: A monitoring system has a polyphase distribution transformer monitoring (PDTM) device that interfaces with electrical conductors electrically connected to a transformer. The PDTM device measures a current and a voltage in each of the electrical conductors simultaneously. Further, the PDTM device has a plurality of free-moving satellite current sensors coupled to flexible cables, and each current sensor is undetached from the other current sensors. Additionally, each satellite current sensor is electrically coupled via a current cable to at least one connector on a control box for which to deliver data indicative of current sensed by the current sensors and each current cable is paired with one of a plurality of voltage cables, and each current cable and voltage cable pair is coupled to the at least one connector.

Abstract: A method and a system for controlling motors is provided to have a vehicle travel smoothly in such a manner that, when a state of charge of a battery for supplying electric power stored to a plurality of motors included in the vehicle is low, a consumption of the battery is reduced by decreasing the electric power supplied to each motor of the plurality of motors. The method of controlling motors includes: determining a state of charge of a battery storing electric power supplied to each motor of a plurality of motors; calculating a present current consumption of each motor of the plurality of motors when the state of charge of the battery is equal to or less than a predetermined reference value; and resetting a power supply to each motor of the plurality of motors, based on the present current consumption of each motor of the plurality of motors.

Abstract: A mounting structure includes a PCB on which first and second conductive patterns are formed, and a shunt resistor mounted on one surface of a substrate via a conductive bonding material. Each of the first and second conductive patterns includes: a first/second lead-out portion and a first/second pull-out portion which is pulled out to the outside of a region of the shunt resistor from the first/second lead-out portion. A resistance value of the shunt resistor is detected between the first pull-out portion and the second pull-out portion. A bonding material flow-out preventing resist is disposed at a portion of a surface of at least one of the first lead-out portion and the second lead-out portion, and a fillet of the bonding material terminates at a position corresponding to a position where the bonding material flow-out preventing resist is disposed.

Abstract: A high-voltage power transmission system is used as an extremely large antenna to extract spatiotemporal space, physical, and geological information from geomagnetically induced currents (GIC). A differential magnetometer method is used to measure GIC and involves acquiring line measurements from a first fluxgate magnetometer under a high-voltage transmission line, acquiring natural field measurements from a reference magnetometer nearby but not under the transmission line, subtracting the natural field measurements from the line measurements, and determining the GIC-related Biot-Savart field from the difference. NASA warning and alarm systems can be triggered based on determinations of GIC amplitude levels that exceed a set threshold value.

Abstract: Provided is a resistor including a first electrode, a second electrode, and a resistive element disposed between the first and second electrodes. Each of the first and second electrodes includes a main electrode portion and a narrow electrode portion with a narrower width than that of the main electrode portion. The resistive element is disposed between the two narrow electrode portions.

Abstract: A method and a device for evaluating the distribution and orientation of ferromagnetic, electrically conductive fibers in a composite material are disclosed. The principle consists in repeatable evaluation of the density of ferromagnetic, electrically conductive fibers at the measured location, and such evaluation is performed within a guaranteed scatter range of the measured data and at a guaranteed accuracy rate. A device to perform the method comprises a C, U or E-shaped ferromagnetic core (1) with distributed or uniform winding of the electric coil (2), where the ferromagnetic core (1) exhibits dimensions A, B, and C, for which we have C?3B and B?A, where A denotes the width of an arm (1.2), B represents the depth of an arm (1.2), and C is the length of the base (1.1).

Abstract: To provide a shunt resistor and a current detection device including the shunt resistor, to which a busbar, a board, and the like can be easily fixed with sufficient strength wherein only minimum processing of electrodes is required. Screwing members (bolt (14) and nut (15)) that are separate members from electrodes (12) of the resistor (10), are fixed on the electrodes (12). The current detection device includes the shunt resistor (10), which has at least a pair of electrodes (12). One screwing member (14) fixed beforehand on at least one electrode (12) is screw fastened with the other screwing member (15) while disposing a prescribed intervening member (20) between the one screwing member and the other screwing member. Here, the prescribed intervening member (20) includes a board mounting a current detection circuit thereon and/or busbars.

Abstract: A monitoring circuit includes a configuration interface, a control circuit, a detection circuit, a direct current voltage source, a switch circuit, and a first resistor. A first end of the configuration interface is separately connected to the direct current voltage source and an input end of the switch circuit; a second end of the configuration interface is separately connected to a first end of the first resistor and an output end of the switch circuit; a control end of the switch circuit is connected to the control circuit; a second end of the first resistor is grounded; the detection circuit is connected to the first end of the first resistor; the configuration interface is configured to connect to a dry contact; the control circuit controls closing or opening of the switch circuit; and the detection circuit detects a voltage between two ends of the first resistor.

Abstract: Configurations are provided for measuring electrical current flow through an AC power cable to a host device. An enclosure is provided that includes various components, such as components of an active RFID tag. A cable clamp is provided that is configured to attach the enclosure to the AC power cable. The cable clamp includes magnetic sensors that are responsive to electrical current flowing through the AC cable to generate signals indicative of the current flowing through the AC cable.

Abstract: A method for detecting the operating condition of each phase of a three-phase capacitor bank in a power distribution system, including the steps of, if the RMS neutral current is above the bank status closed setting, comparing the phase angle of neutral current (IN) with respect to voltage on one of the phases (VA, VB or VC) and sending an alarm signal when the comparison of the phase angle of neutral current with respect to the phase voltage differs appreciably from the expected phase angles.

Abstract: Isolated capacitance line voltage sensing is provided that avoids metal-to-metal contact for voltage sensing of a power signal present on a power wire. An external conductor is positioned by the power wire, creating a capacitor with the power wire conductor, insulation, and external conductor. The capacitance is used to measure the electric field, indicating a voltage level for the powered wire. The impedance mismatch caused by the capacitance is transformed. The impedance transformation circuit may be integrated with the external conductor, allowing voltage sensing by a voltage meter having a lower input impedance. A manual or automatic calibration circuit may be provided to ensure the measured voltage represents the actual voltage on the power wire.

Abstract: An arrangement includes a gas insulated switchgear and a RC voltage divider. The gas insulated switchgear includes a switchgear compartment and a voltage divider compartment. The RC voltage divider and the gas insulated switchgear together at least partially form a hermetically sealed common gas compartment. A method for assembling the arrangement is also provided.

Abstract: A coil unit includes a non-magnetic conductive plate which is disposed along an axis of a coil, and a magnetic body. The magnetic body includes a first portion which is positioned in an outer side than an outline of one side of the conductive plate in the axis direction of the coil, and a second portion which is positioned in an outer side than an outline of the other side of the conductive plate in the axis direction of the coil. When viewing from the axis direction of the coil, the first and second portions are positioned on a side of the conductive plate where is opposite to a side which faces the coil.

Abstract: The invention relates to a method for ascertaining an insulation resistance (2) of a test object (3) to be examined, wherein a decoupling capacitor (4) having a first capacity, and a measuring capacitor (5) having a second capacity are connected in series with the test object (3) in such a way that the decoupling capacitor (4) and the measuring capacitor (5) form a low-pass with the insulation resistance (2) of the test object (3), wherein a predetermined voltage (9) is applied to the series connection, the measuring capacitor voltage (8) declining on the measuring capacitor (5) is ascertained, and, by means of an evaluation unit (7), considering the first capacity, the second capacity and the ascertained measuring capacitor voltage (8), the insulation resistance (2) of the test object (3) is determined.

Abstract: A voltage measurement device is provided. The voltage measurement device includes a contact portion configured to contact an electric wire for transmitting an alternating current (AC) voltage and to output an induced voltage induced by the AC voltage in a surface of the electric wire, a capacitive element connected in series to the contact portion, and a controller configured to calculate amplitude of the AC voltage using the induced voltage output from the contact portion and a second voltage output from the capacitive element.

Abstract: A device and a method used to measuring a real power transmitted by the power line are provided. The device comprises a detecting unit and a calculating unit, for obtaining the power factor and the real power according to a sensing voltage signal and a sensing current signal. The device is characterized by: the detecting unit having an electric field detector and a magnetic field detector, two electrodes of the electric field detector respectively disposed adjacent to the power wires, the sensing voltage signal being the voltage difference between the two electrodes, two coils with metal cores of the magnetic field detector respectively disposed adjacent to the power wires, the winding directions of the two coils being contrary, the two coils being coupled in series based on the same sensing current direction for obtaining the sensing current signal.

Abstract: A distribution block element having dual-level opposed input and output couplings and integral mechanical connectors to additional adjacent distribution block elements, allowing expansion by addition of distribution block elements. First levels of the couplings are spaced apart for a fuse of a first size and the second, lower levels of the couplings are spaced apart for a fuse of a second size, and for direct flat plate conductors. When two elements are connected adjacently, the spacing between the second level of adjacent couplings is the same as the spacing between the second level of opposed couplings in each element. Thus, the flat plate conductors can be used both for electrically connecting opposed input and output couplings and for electrically connecting input couplings of adjacent elements. Notches in the flat plate connectors receive fasteners and two flat plate connectors can be juxtaposed to receive the same fastener without stacking.

Abstract: Semiconductor devices, methods of manufacture thereof, and capacitors are disclosed. In some embodiments, a semiconductor device includes a first capacitor and a protection device coupled in series with the first capacitor. A second capacitor is coupled in parallel with the first capacitor and the protection device.

Abstract: Provided herein is a power-on reset circuit and a semiconductor memory device having the power-on reset circuit. The power-on reset circuit may include a reference voltage generation circuit configured to generate a reference voltage using an external supply voltage that is externally input, and a power-on reset signal generation circuit configured to generate a power-on reset signal by sensing a potential level of the reference voltage when the external supply voltage increases to a set level or more. The power-on reset signal generation circuit may be configured to, when the reference voltage changes depending on the temperature variation, control a sensing level to compensate for the change in the reference voltage.

Abstract: An enclosure for an energy monitoring current transformer includes upper housing that houses an upper transformer core section. Lower housing houses a transformer coil and a lower transformer core section. When the enclosure is assembled there is an overlap between the cap for the lower housing and the lower housing that lengthens a creepage path from the upper transformer core to the external surface of the enclosure.

Abstract: A method for signaling and controlling in a power grid coupling a plurality of actuators for providing power signals is provided. At a first actuator, a voltage problem is detected, a communication signal is generated based on the detected voltage problem, and the generated communication signal is transmitted over the power grid. At a second actuator, the transmitted communication signal is received, a control action is generated based on the received communication signal and the generated control action is transmitted over the power grid towards the first actuator.

Abstract: A mechanical fault indicator of the automatic reset includes the core, the dial, the lock, the indicating rods, and the shell. The core includes the clip-on core, fixed core, connecting core and movable iron core. The pointer includes the indicating axis of rotation, the pointer connection and the indicating rod. The lock includes the lock axis of rotation, the lock hook and balancing weight. When using the indicator, clip the wire of the transmission line into the two-part clip-on core. When a short circuit fault happens, the indicating rod falls out of the housing, of which the action indicates failure. When the circuit is back to normal, the indicating rod resets automatically. The indicator has the advantages of: low cost, long service life, purely mechanical, no circuit and battery, and the installation is simple and convenient.