JP6744183B2 - Ground fault current detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a ground fault current detector for detecting a ground fault current in a plurality of illumination lights connected to a common distribution line installed on a road or a tunnel.

The distribution lines for interchange lights, service areas, junctions, etc. on expressways and tunnel lighting fixtures are generally three-phase, four-wire lines, and multiple lights are connected to the distribution line on a system-by-system basis. Has been done. For example, one system is configured by connecting 10 to 30 illumination lamps in parallel. In such an illuminating lamp, when a ground fault occurs due to insulation deterioration or the like, the earth leakage relay operates, the circuit breaker opens, and the illumination of the system in which the ground fault occurs disappears.

Therefore, the worker identifies the ground fault portion, separates the portion, and performs the restoration work. Here, the work of identifying the ground fault location is performed in the following procedure. Check the insulation resistance in the electrical room. Open the lid of the joint box at the midpoint of the interrupted system, disconnect the distribution line to the electric room side and the tip side, and measure the insulation resistance of both. Open the joint box lid at the bad middle point and repeat the same procedure. After identifying the ground fault, disconnect the distribution line at that part, reconnect the distribution line that was separated so far, and restore power.

Thus, the restoration work requires a great deal of labor and time. As a solution to this, in Patent Document 1, a leakage current measuring current transformer (CT) is provided on the power supply side or the downstream side of each branch connection point of a distribution line in which a plurality of loads are branch-connected at intervals. Equipped with a terminal slave station that wirelessly transmits the leakage current value detected by the leakage current measurement CT as leakage current information, and the leakage current information transmitted from the terminal slave station is installed in the maintenance inspection vehicle that moves along the distribution line. The ground fault section is evaluated by the leak current information received by the received mobile master station. By the above method, the disconnection of the distribution line is unnecessary, and the labor can be reduced.

JP, 11-41796, A

The terminal slave station described above operates on the electric power supplied from the distribution line. However, when a ground fault of high current occurs, the power supply to the terminal slave station is cut off when the ground fault relay operates. In this case, the terminal slave station cannot perform wireless communication. By the way, a battery may be used as a power source in a communication device for specific low power wireless communication. Therefore, by using a battery for the terminal slave station, the problem that wireless communication cannot be performed as described above is solved.

However, since each terminal slave station transmits the leakage current information in response to the request from the mobile master station, the terminal slave station communicates with the mobile master station even if no ground fault has occurred in the lighting. In this way, the terminal slave station operates regardless of the occurrence of a ground fault, the power consumption of the battery increases, and the battery is exhausted quickly. In this case, there is a possibility that the information when the ground fault occurs cannot be transmitted to the mobile master station. Also, when transmitting information from each terminal slave station to the master station, if abnormal current occurs due to lightning surge or noise other than ground fault, the terminal slave station may operate and transmit information to the master station. .. As described above, when the terminal slave station operates each time an abnormal current other than the ground fault occurs, the power of the battery is consumed unnecessarily and the battery is consumed. Therefore, when the terminal slave station cannot perform wireless communication when necessary, it is necessary to specify not only the ground fault location but also the cause of the wireless communication failure, which requires a great deal of labor.

Further, in the tunnel lighting equipment, there may be a large number of lighting lights connected to one system. In the tunnel, there are many problems such as lane regulation and high-altitude work within the regulation time in order to identify and restore the ground fault. Therefore, it is necessary to surely identify the ground fault portion and shorten the working time.

In view of the above, it is an object of the present invention to provide a ground fault current detector that can be installed in each lighting of highways and tunnels and that can reliably identify a ground fault location and that has low power consumption.

The ground fault current detector of the present invention is provided for each of a plurality of lamps connected to a common distribution line, a detection unit for detecting an abnormal current flowing in the distribution line, and when a ground fault current occurs It is provided with a notifying unit that changes the display to notify, and a monitoring unit that monitors the abnormal current and outputs a drive signal to the notifying unit when the abnormal current is a ground fault current. When the monitoring unit confirms that the abnormal current is a ground fault current, it outputs a drive signal, and the notification unit changes the display according to the drive signal from the monitoring unit and holds the changed state.

When an abnormal current flows through the illumination lamp or the distribution line between the illumination lamps, the detection unit detects the abnormal current. The monitoring unit determines whether the abnormal current is a ground fault current, outputs a drive signal if it determines that it is a ground fault current, and does not output a drive signal if it determines that it is not a ground fault current. The notification unit operates to change the display state when the drive signal is input. The display state once changed is retained as it is, and the ground fault portion can be easily specified.

A battery for operating the notification unit is provided, the monitoring unit operates by an abnormal current detected by the detection unit, the notification unit is switchable between a normal display state and an abnormal display state, and the notification unit is a battery. The normal display state is switched to the abnormal display state by using the electric power of, and the abnormal display state is maintained. This eliminates the need for a power supply for operating the monitoring unit. The battery can be used only to operate the alarm. In addition, since the changed display state is retained, it is not necessary to consume battery power.

A power supply unit that temporarily stores the power supplied from the battery and supplies the stored power to the notification unit is provided. Powers the alarm unit to operate. The battery is used to charge the power supply unit, and the power of the battery is supplied to the notification unit through the power supply unit. That is, the notification unit indirectly uses the electric power from the battery.

The notification unit is provided with a confirmation unit that notifies the light by changing the light emission and allows the light emitted from the notification unit to be visually recognized from the outside of the illumination lamp. The change of light can be confirmed from the outside of the illuminating lamp, and the illuminating lamp having the ground fault can be easily identified.

A reset unit is provided that resets the notification unit that has changed the display after a certain period of time. The notification unit changes the display to notify the occurrence of the ground fault current, but the notification unit is automatically reset after a certain period of time. The notification section can be returned to the original display without any trouble.

According to the present invention, by limiting the operation using the electric power of the battery when monitoring the occurrence of the ground fault, the electric power of the battery can be used only to notify that the ground fault is detected. As a result, the consumption of the battery can be reduced and the life of the battery can be extended. In addition, it becomes possible to install the ground fault current detectors on a plurality of illumination lamps at low cost, and by continuing to notify the illumination lamp where the ground fault has occurred, it is possible to reliably identify the ground fault location.

Schematic block diagram of the road illumination light equipment provided with the ground fault current detector of the first embodiment of the present invention Block diagram of the ground fault current detector of the first embodiment Electrical circuit diagram of ground fault current detector (A) The figure which looked at the inside of the illumination pillar which removed the lid from the front, (b) The sectional view of the illumination pillar provided with the ground fault current detector Abnormal current detection time chart when delay time is not set Time chart of abnormal current detection when a ground fault occurs Time chart for detecting abnormal current due to lightning surge The figure which shows the operating characteristic of the indicator which comprises an alerting|reporting part, and the relationship of the discharge current of the capacitor which comprises the electric power feeding part required to operate an indicator Time chart from abnormal current detection to notification Electric circuit diagram of the ground fault current detector of the second embodiment (A) A view of an illumination column whose display state is visible from the outside as seen from the front, (b) A sectional view of the illumination column whose display state is visible from the outside, (c) Other optical fibers connected to the display Cross section of bolt with connected ends Schematic block diagram of the road illumination light equipment provided with the ground fault current detector of 3rd Embodiment Electrical circuit diagram of ground fault current detector Electric circuit diagram of the ground fault current detector of the fourth embodiment (A) Front view of an illumination column whose display state is visible from the outside, (b) Cross-sectional view of the illumination column whose display state is visible from the outside Diagram showing the display state of each local current detector when a ground fault occurs in the lighting Diagram showing the display state of each local current detector when a ground fault occurs on the distribution line between the lighting (A) Front view of an illumination column whose display state is visible from the outside, (b) Cross-sectional view of the illumination column whose display state is visible from the outside

(First embodiment)
The ground fault current detector according to the first embodiment of the present invention is used for a road illumination light facility installed on a highway and is provided for each of a plurality of illumination lights. The lighting is divided into a plurality of systems according to the installation location. One system is composed of a plurality of (N) illumination lights and is managed for each system in the electric room. As shown in FIG. 1, a high-voltage transformer 2 is provided in the electric room 1, and the high-voltage transformer 2 and the illumination lamp 3 are connected by a three-phase four-wire type distribution line 4 for power supply and a distribution line 5 for dimming. It A circuit breaker 6, a switch 8 of an automatic light control device 7, and a ground fault relay 9 are provided on the distribution line 4 in the electric room 1.

The plurality of lighting lamps 3 are connected in parallel to the distribution line 4. The illuminating lamp 3 includes a lamp 10, a ballast 11, a joint box 14 accommodating a connection terminal 12 and a breaker 13. The lamp 10 is mounted on the upper part of the lighting column 15, and the joint box 14 is mounted inside the lighting column 15.

The distribution lines 4 and 5 are drawn into the illumination column 3 and connected to the plurality of connection terminals 12 provided on the terminal block. The power distribution lines 4 are respectively connected to the three-phase connection terminals 12, and the R terminal and the N terminal of the three-phase connection terminals 12 are connected. The breaker 13, the ballast 11, and the lamp 10 are connected between the R terminal and the N terminal. The dimming distribution line 5 is connected to the S terminal, and the S terminal and the N terminal are connected. The respective illumination lights 3 are similarly connected, but the R, S, and T terminals are distributed and connected for each illumination light 3.

Each of the illumination lamps 3 is provided with a ground fault current detector 16 for detecting the generated ground fault. As shown in FIGS. 2 and 3, the ground fault current detector 16 includes a detection unit 20 that detects an abnormal current flowing through the distribution line 4, a notification unit 21 that notifies an abnormality when a ground fault current occurs, and an abnormality. A monitoring unit 22 that monitors the current and outputs a drive signal to the notification unit 21 when the abnormal current is a ground fault current, and an abnormal current detection value to the monitoring unit 22 to prevent erroneous detection of the abnormal current due to lightning. And a limiting unit 23 that limits input.

Then, the ground fault current detector 16 is provided with a battery 25 as a power source for operating the notification unit 21. Further, the ground fault current detector 16 includes a power supply unit 26 that temporarily stores the power supplied from the battery 25 and supplies the stored power to the notification unit 21. The power supply unit 26 stops the power supply from the battery 25 and supplies power to the notification unit 21. The notification unit 21 operates by the power supplied from the power supply unit 26. That is, the notification unit 21 operates using the power of the battery 25.

Each unit except the detection unit 20 is housed in a case 30, and the detection unit 20 is connected to the case 30 by a lead wire. As shown in FIG. 4, the case 30 of the ground fault current detector 16 is installed in the joint box 14. An opening 31 is formed in the illumination column 15, and a lid 32 is provided in the opening 31 so as to be opened and closed by a bolt 33. When the lid 32 is opened, the joint box 14 appears.

As shown in FIG. 1, the ground fault detector 16 detects an abnormal current in the distribution line 4 connecting the ballast 11 and the connection terminal 16. The detection unit 20 is a current transformer, and the current transformer clamps the distribution line 4 on the upstream side of the ballast 11. An output current of the detection unit 20 when an abnormal current such as a ground fault current is detected is rectified by a rectifier circuit, smoothed by a capacitor smoothing circuit, and converted into an abnormal current detection value, and the abnormal current detection value is monitored by the monitoring unit 22. To enter.

The monitoring unit 22 is composed of a reset IC and operates by an electromotive force generated when the detection unit 20 detects an abnormal current. Therefore, the abnormal current can be monitored without a power source. The monitoring unit 22 confirms whether the generated abnormal current is a ground fault current or a ground fault current. The abnormal current in the illuminating lamp 3 is also generated by lightning surge or noise in addition to the ground fault current. Therefore, the monitoring unit 22 determines the input abnormal current detection value based on the reference value, and outputs a drive signal when the abnormal current detection value is input from the detection unit 20 that exceeds the reference value. That is, when the input abnormal current detection value exceeds the reference value, the monitoring unit 22 determines that it is a ground fault current and outputs a drive signal. When the abnormal current detection value is less than or equal to the reference value, the monitoring unit 22 determines that the current is not the ground fault current and does not output the drive signal.

The limiting unit 23 is composed of a Zener diode, and is arranged in front of the monitoring unit 22. The limiting unit 23 absorbs the lightning surge voltage to protect the reset IC of the monitoring unit 22 and limits the input of the abnormal current detection value to the monitoring unit 22 in order to prevent erroneous detection of the abnormal current due to the lightning surge. ..

Here, the abnormal current detection value due to the ground fault current has a higher input voltage and longer input time than the abnormal current detection value due to noise. The abnormal current detection value due to lightning surge has a high input voltage but a short input time. Therefore, the input voltage threshold value and the delay time with respect to the input time are set as the reference value. The input voltage threshold is determined by setting the reference voltage of the reset IC. Further, by connecting the capacitor C4 to the capacitor connection terminal (CT) of the reset IC, the delay time is determined according to the capacity of the capacitor C4.

The abnormal current flowing through the distribution line 4 in the illuminating lamp 3 is detected by the detection unit 20. The abnormal current detection value generated by converting the output current from the detection unit 20 is input to the monitoring unit 22. As shown in FIG. 5, when the input voltage of the abnormal current detection value exceeds the threshold value, the normal reset IC outputs a reset signal. However, as shown in FIG. 6, in the reset IC in which the delay time T0 is set, that is, in the monitoring unit 22, even if the abnormal current detection value in which the input voltage exceeds the threshold value is input, the input time of the input voltage is When it is shorter than the delay time, the reset signal (driving signal) is not output. When the input time of the input voltage is equal to or longer than the delay time, the reset signal (driving signal) is output. Therefore, the monitoring unit 22 can correctly distinguish the abnormal current due to noise and the ground fault current, and outputs the drive signal when the input abnormal current detection value exceeds the reference value.

The impulse current waveform of the lightning surge current is set to 8/20 μs for induced lightning and 10/350 μs for direct lightning. As shown in FIG. 7, when the detection unit 20 detects an abnormal current due to such a lightning surge, the input voltage of the abnormal current detection value is limited and input to the monitoring unit 22. The input voltage is limited to a constant voltage determined by the Zener voltage of the limiting unit 23. Even if the input voltage exceeds the reference voltage, the input time of the input voltage is shorter than the delay time. By the way, in winter lightning, the impulse current waveform of the lightning surge current may be 10/1000 μs. In the case of such a lightning surge, since the wave tail length becomes long, the input time of the input voltage also becomes long. Therefore, when the Zener voltage is set to a value that is higher than the reference voltage by about 1 to 1.5 V, the input voltage becomes lower, so that the input voltage becomes lower than the input voltage threshold value before the delay time is reached. As a result, the abnormal current detection value does not exceed the reference value, and it is possible to prevent the abnormal current due to a lightning surge from being erroneously detected as a ground fault current.

The notification unit 21 changes the display state by the drive signal from the monitoring unit 22 to notify the change, and holds the changed display state. The notification unit 21 includes a display 40 whose display state changes, and a notification switch 41 which operates the display 40 by a drive signal. As the display 40, a Magsine (registered trademark), that is, a magnetic reversal display 40 for reversing and displaying a disk of a permanent magnet by an instantaneous pulse current is used. The display 40 is switchable between a normal display state and an abnormal display state, and the color of the disc in the normal display state is different from the color of the disc in the abnormal display state. As shown in FIG. 2, a window 42 for confirming the display state of the display 40 is formed in the joint box 14. When the lid 32 of the illumination column 15 is opened, the display state can be visually recognized from the outside through the window 42.

The display 40 has a set coil 43 and a reset coil 44 for reversing the disc. When a current flows through the set coil 43, an abnormal display state occurs, and when a current flows through the reset coil 44, a normal display state occurs. Note that once the display state changes, the display state is maintained even if the current is cut off.

The battery 25, the display 40, and the notification switch 41 are connected in series to form a power supply circuit. The notification switch 41 is an N-type MOSFET, which is normally off and the power supply circuit is open. Using the drive signal as a trigger, the notification switch 41 is turned on, and the power supply circuit is closed to conduct electricity.

The set coil 43 and the reset coil 44 are connected in parallel, the first switch 45 and the notification switch 41 are connected to the set coil 43, and the second switch 46 is connected to the reset coil 44. The first and second switches 45 and 46 are turned on/off in conjunction with a reset switch 47 for switching from the abnormal display state to the normal display state. Normally, the reset switch 47 is off, the first switch 45 is on, and the second switch 46 is off. When the reset switch 47 is turned on, the first switch 45 is turned off and the second switch 46 is turned on so that the reset coil 44 is energized.

When the notification switch 41 is turned on, a current flows through the set coil 43, and the display 40 changes from the normal display state to the abnormal display state. When the notification switch 41 is off, the power supply circuit is open, but when the reset switch 47 is on, power is supplied from the battery 25, current flows through the reset coil 44, and the display 40 normally displays from the abnormal display state. Change to state.

The power supply unit 26 includes a capacitor 50 that stores electric power from the battery 25, and a changeover switch 51 that switches between power supply from the battery 25 and power supply from the capacitor 50. The battery 25 and the capacitor 50 are connected in parallel with the display 40. The changeover switch 51 is a P-type MOSFET and is connected between the battery 25 and the display 40 and between the battery 25 and the capacitor 50. The changeover switch 51 is normally turned on, and the changeover switch 51 is turned off by using the drive signal as a trigger. When the changeover switch 51 is turned on, the power of the battery 25 is supplied to the capacitor 50 and the capacitor 50 is charged. When the changeover switch 51 is off, the power supply from the battery 25 to the display 40 is cut off and the power supply from the capacitor 50 is switched. The power from the capacitor 50 is supplied to the display 40.

The display 40 operates by the power supply from the capacitor 50. The operating characteristics of the display 40 are shown in FIG. The region above the curve of this characteristic is the operating region. If the current value when the power is supplied from the capacitor 50 is within the operating range, the display 40 operates. The discharge current value of the capacitor 50 is proportional to the voltage and electrostatic capacity of the battery 25. The capacitance becomes smaller due to product variations, temperature changes, and aging. The smallest current value considering these is A'in the figure. Therefore, the capacitance of the capacitor 50 is selected so that the discharge current value A exceeds the minimum current value A'. As a result, the display 40 can be stably operated by the power supply from the capacitor 50.

The monitoring unit 22 constantly monitors the abnormal current of the distribution line 4 of the illumination lamp 3. As shown in FIG. 9, when the detection unit 20 detects an abnormal current, the abnormal current detection value is input to the monitoring unit 22. The monitoring unit 22 checks the abnormal current detection value based on the reference value. For example, even if the input voltage of the abnormal current detection value exceeds the input voltage threshold value, if the input time does not exceed the delay time, for example, 200 ms, the monitoring unit 22 determines that the abnormal current is not detected and outputs the drive signal. Do not output. At this time, the notification switch 41 is off and the changeover switch 51 remains on. A current flows from the battery 25 to the capacitor 50, and the capacitor 50 is constantly charged. On the other hand, no current flows from the battery 25 to the display 40, and the display 40 is in the normal display state.

When a ground fault occurs in the distribution line 4 of the illuminating lamp 3, the detection unit 20 detects the ground fault current, and the monitoring unit 22 determines whether or not the ground fault current is detected based on the input abnormal current detection value. When the input voltage of the abnormal current detection value exceeds the input voltage threshold and the input time exceeds the delay time, the monitoring unit 22 determines that the current is the ground fault current and outputs the drive signal. At the same time that the notification switch 41 is turned on, the changeover switch 51 is turned off. The drive signal is output only for the time corresponding to the input time. That is, the drive signal is output for the time obtained by subtracting the delay time from the input time. The electric power from the battery 25 is not supplied to the display 40, the electric charge stored in the capacitor 50 is discharged, and the discharge current flows through the set coil 43. The disk of the display unit 40 is reversed and the normal display state is changed to the abnormal display state.

When the drive signal is not output, the notification switch 41 is turned off and the changeover switch 51 is turned on at the same time. A current flows from the battery 25 to the capacitor 50, and the capacitor 50 is charged. Since no power is supplied to the display device 40, the abnormal display state is held. The operator opens the lid 32 of each illumination lamp 3 and confirms the display state of the indicator 40 through the window 42 of the joint box 14. In this way, if the display state of the display device 40 changes when a ground fault occurs, the abnormal display state is maintained, so that it is possible to continue to notify the abnormality and reliably identify the lighting lamp 3 in which the ground fault has occurred. can do. When the reset switch 47 is turned on, the display on the display unit 40 returns from the abnormal display state to the normal display state.

Then, the notification unit 21 consumes electric power when switching the display state, but does not consume electric power during the display, so that it is possible to suppress the consumption of the battery 25. As a result, the life of the battery 25 can be extended and the labor for battery replacement can be reduced. Therefore, it suffices to use the battery 25 only for operating the notification unit 21, and the ground fault current detector 16 with low power consumption can be realized. Moreover, by incorporating the battery 25 in the case 30, the ground fault current detector 16 can be made compact, and the ground fault current detector 16 can be easily installed in each of the illumination lamps 3.

(Second embodiment)
The ground fault current detector 16 of the second embodiment is shown in FIG. The notification unit 21 notifies by changing the light emission. The indicator 40 of the notification unit 21 is an LED, and the notification unit 21 includes a notification switch 41 for operating the display 40 and a drive unit 60 for turning on the display 40. The power supply unit 26 that supplies the power from the battery 25 to the display 40 opens and closes the power supply circuit to switch between supplying and stopping the power supply of the battery 25 to the display 40. The notification switch 41 operates the power supply unit 26 so as to close the power supply circuit. The notification switch 41 is operated by the drive signal from the monitoring unit 22, and the notification unit 21 is supplied with power from the battery 25. The display device 40 changes the light emission from the normal display state in which the light is off to the abnormal display state in which it blinks, and gives a notification while maintaining the state after the display. The rest of the configuration is the same as that of the first embodiment. In the figure, reference numeral 61 denotes a battery remaining amount confirmation unit for checking the remaining amount of battery voltage.

The notification switch 41 is an N-type MOSFET and is connected to the power supply unit 26. The notification switch 41 is normally off, and the power supply circuit is cut off at this time. When the notification switch 41 is turned on by using the drive signal as a trigger, the power supply unit 26 operates. Power from the battery 25 is supplied to the display 40, and the display 40 becomes operable.

The driving unit 60 is an oscillation circuit formed of a resistor R6, a capacitor C8, an NPN transistor Q1 and a PNP transistor Q2. When the power supply unit 26 operates and the power supply circuit is closed, the drive unit 60 is energized and the drive unit 60 starts operating. When the drive unit 60 outputs an ON signal, a current flows through the display 40, and the display 40 lights up. When the drive unit 60 does not output the ON signal, no current flows in the display 40 and the display 40 is turned off. The display unit 40 blinks at a predetermined timing when the drive unit outputs an ON signal at a predetermined timing. As a result, the display device 40 switches between a normal display state in which it is turned off and an abnormal display state in which it blinks. The blinking timing is determined by the capacitance of the capacitor C8, the resistance value of the resistor R6, and the base voltage of the NPN transistor Q1. For example, the blinking timing is 0.01 second on and 0.64 second off.

The power supply unit 26 includes a changeover switch 62 that switches between supply and stop of power from the battery 25. The changeover switch 62 is connected between the battery 25 and the display 40 in the power supply circuit. A latch relay is used as the changeover switch 62. When the changeover switch 62 is in the operating state, the power supply circuit is closed and the battery 25 supplies power to the display 40. When the changeover switch 62 is in the rest state, the power supply circuit is opened, and the power supply from the battery 25 to the display 40 is stopped. Normally, the changeover switch 62 is held in a rest state.

The changeover switch 62 has a set coil 63 for bringing the operating state and a reset coil 64 for returning from the operating state to the rest state, and the notification switch 41 is connected to the set coil 63. Further, a set switch 65 for setting the changeover switch 62 in an operating state and a reset switch 66 for setting the changeover switch 62 in a rest state are provided. When the set switch 65 is operated, the set coil 63 is energized, and when the reset switch 66 is operated, the reset coil 64 is energized.

When a ground fault occurs in the distribution line 4 of the illuminating lamp 3, the output current of the detection unit 20 that detects the abnormal current at this time is rectified by the quadruple voltage rectifier circuit and smoothed by the smoothing circuit to obtain the abnormal current detection value. The converted abnormal current detection value is input to the monitoring unit 22. The monitoring unit 22 determines whether or not it is a ground fault current based on the input abnormal current detection value. When the monitoring unit 22 determines that the current is a ground fault current, the monitoring unit 22 outputs a drive signal. The notification switch 41 is turned on, the set coil 63 is energized, the changeover switch 62 is switched to the operating state, and the drive unit 60 is supplied with power from the battery 25. Even if the notification switch 41 is turned off, the changeover switch 62 maintains the operating state.

When the drive unit 60 is energized, the capacitor C8 is charged, and when the voltage exceeds a predetermined charging voltage, the transistors Q1 and Q2 are turned on in order and an ON signal is output. The display 40 is energized and the display 40 lights up. At this time, no current flows through the capacitor C8, so when the capacitor C8 discharges, the transistors Q1 and Q2 are turned off. When the ON signal is no longer output, the display 40 is turned off. When the capacitor C8 is charged again and the ON signal is output at a predetermined timing, the display 40 is turned on at a predetermined timing. By repeating this, the display unit 40 blinks to enter the abnormal display state. During this time, the power of the battery 25 is consumed, but since the time during which the display 40 is on is very short, the consumption of the battery 25 is suppressed. As a result, the display 40 can maintain the abnormal display state for a long period of time, can continue to notify the abnormality, and can reliably identify the illuminating lamp 3 in which the ground fault has occurred.

Here, in order to easily confirm the display state of the display device 40, a confirmation unit 70 that allows the light emitted from the notification unit 21 to be visually recognized from the outside of the illumination lamp 3 is provided. As shown in FIG. 11, the confirmation unit 70 guides the light emitted from the notification unit 21 to the outside of the illumination lamp 3 to make the display state visible. A bolt for fixing the lid 32 of the illumination column 3 is a perforated bolt 71, and the bolt 71 and the display 40 are connected by an optical fiber 72. One end of the optical fiber 72 is connected to the display 40, and the optical fiber 72 is pulled out from the inside of the joint box 14 and passed through the through hole 73 of the bolt 71. The eyelet 74 is attached to the other end of the optical fiber 72, the other end of the optical fiber 72 is inserted into the through hole 73 of the bolt 71, and the vinyl cap 75 is covered. The optical fiber 72 is not twisted even when the bolt 71 is rotated, and the lid 32 can be opened and closed. A translucent cap 76 is inserted into the through hole 73 of the bolt 71 to prevent water from entering the illumination column 3.

The light of the display 40 reaches the other end of the optical fiber 72 inserted into the through hole 73 of the bolt 71, and the light is emitted from the through hole 73 of the bolt 71. Thereby, it is possible to confirm that the display 40 is blinking from the outside of the illumination column 3. Therefore, it is not necessary to open the lid 32, and the specific time of the illumination lamp 3 in which the ground fault has occurred can be shortened.

(Third Embodiment)
The ground fault current detector 16 of the third embodiment is shown in FIGS. In the ground fault current detector 16, the first and second detection units 20a and 20b and the two monitoring units 22, the limiting unit 23, the power feeding unit 26 and the notification unit 21 corresponding to the respective detection units 20a and 20b are provided. I have it.

A current transformer is used for the two detection units 20a and 20b, the first detection unit 20a detects the ground fault current generated in the illumination lamp 3, and the second detection unit 20b detects the adjacent illumination lamps 3. The ground fault generated in the distribution line 4 to be connected is detected. The current transformer of the first detection unit 20a clamps the distribution line 4 on the downstream side of the joint box 14, that is, the distribution line 4 between the breaker 13 and the ballast 11. The current transformer of the second detection unit 20b clamps the distribution line 4 that connects the joint box 14 and the downstream illuminating lamp 3, that is, the illuminating lamp 3 on the side far from the electric room 1. The second detection unit 20b is arranged inside the illumination column 15.

A magnetic reversal display is used as the display 40 of the notification unit 21, and the display 40 is provided corresponding to each of the detection units 20a and 20b. A power supply circuit for operating each notification unit 21 is formed. Each power supply circuit shares one battery 25 and is connected in parallel to the battery 25. Each part except for the two detection parts 20a and 20b is housed in a case 30, and each detection part 20a and 20b is connected to the case 30 by a lead wire. The other configuration of the ground fault current detector 16 is the same as that of the first embodiment. In FIG. 12, reference numeral 80 is a ground fault current detector that detects a ground fault current in the distribution line 4 in the electric room 1.

When a ground fault occurs in the illuminating lamp 3, the first detection unit 20a detects the ground fault current and the notification unit 21 operates. In this case, the display of the display 40 connected to the first detection unit 20a changes from the normal display state to the abnormal display state. The display does not change on the display 40 connected to the second detection unit 20b. When a ground fault occurs in the distribution line 4 between the illumination lamps 3, the second detection unit 20b detects the ground fault current and the notification unit 21 operates. In this case, the display on the display 40 connected to the second detection unit 20b changes from the normal display state to the abnormal display state. The display does not change on the display 40 connected to the first detection unit 20a. As a result, the location where the ground fault has occurred can be separated, and the time required for the restoration work can be shortened.

(Fourth Embodiment)
The ground fault current detector 16 of 4th Embodiment is shown in FIG. The ground fault current detector 16 includes two detection units 20a and 20b, and two monitoring units 22 corresponding to the detection units 20a and 20b, a limiting unit 23, and a power feeding unit 26. Then, one notification unit 21 is provided for the two detection units 20a and 20b. Other configurations are the same as those of the second embodiment.

As shown in FIG. 15, the ground fault current detector 16 is attached by a magnet to a rib 81 formed so as to surround the opening 31 of the illumination lamp 3. The confirmation unit 70 is provided near the ground fault current detector 16. The lid 32 is attached to the rib 81 by a bolt 71 so as to be openable and closable. The upper bolt 71 is a perforated bolt, an optical fiber 72 from the ground fault current detector 16 is connected to this bolt 71, and the presence or absence of light emission can be visually confirmed through a through hole 73 of the bolt 71. The structure of the confirmation unit 70 is the same as that shown in FIG. Thereby, the state of the display 40 can be confirmed from the outside of the illumination lamp 3.

Each detection unit 20a, 20b is arranged in the illumination column 15, and the current transformer of the first detection unit 20a clamps the distribution line 4 connecting the joint box 14 and the lamp 10 above. The current transformer of the second detection unit 20b clamps the distribution line 4 wired from the joint box 14 toward the illumination lamp 3 on the downstream side.

The notification unit 21 includes a display 40 including an LED, two notification switches 41, and one drive unit 60. A notification switch 41 is provided corresponding to each of the two detection units 20a and 20b. When each notification switch 41 is turned on, each power supply unit 26 operates to supply power from the battery 25 to the drive unit 60. The drive unit 60 has a blinking circuit 84 using a multivibrator IC 82 and a delay circuit 83, and a drive switch 85 for operating the display 40, that is, for turning on the LED. The delay circuit 83 delays the trigger input to the multivibrator IC 82 and causes the multivibrator IC 82 to oscillate. Since the time constant of the CR connected to the first detection unit 20a and the time constant of the CR connected to the second detection unit 20b in the multivibrator IC 82 are different, the oscillation cycle of the multivibrator IC 82 is different. .. Therefore, the blinking cycle of the display unit 40 at the time of detection by each of the detection units 20a and 20b is different. For example, when the first detection unit 20a detects, it blinks slowly, and when the second detection unit 20b detects, it blinks quickly.

When a ground fault occurs in the illumination lamp 3, the first detection unit 20a detects the ground fault current. Then, when the monitoring unit 22 outputs the drive signal, the notification switch 41 is turned on, the changeover switch 62 is switched to the operating state, and the power from the battery 25 is supplied to the drive unit 60. In the drive unit 60, the trigger signal controlled by the delay circuit 83 is periodically input to the multivibrator IC 82, and the ON signal is output at a predetermined cycle. When the drive switch 85 is turned on in response to the ON signal, the display 40 is energized and the display 40 blinks in a predetermined cycle.

Here, the 2nd detection part 20b provided in the illuminating lamp 3 in which the ground fault occurred does not detect the ground fault current. However, an abnormal current due to a ground fault flows in the distribution line 4 on the upstream side of the illumination lamp 3. The second detection unit 20b of the ground fault current detector 16 provided in the lighting lamp 3 on the upstream side of the lighting lamp 3 detects an abnormal current due to the ground fault. Therefore, as shown in FIG. 16, in the ground fault current detector 16 provided in the illumination lamp 3 on the upstream side of the illumination lamp 3 in which the ground fault occurs, the display 40 blinks. However, the blinking cycle is different from the blinking cycle in the ground fault current detector 16 of the illumination lamp 3 in which the ground fault has occurred. Thereby, it is possible to easily identify that the ground fault has occurred in the illumination lamp 3.

When a ground fault occurs in the distribution line 4 between the illumination lamps 3, the second detection unit 20b of the ground fault current detector 16 on the upstream side of the ground fault location detects the ground fault current. In this case as well, the display 40 blinks in a predetermined cycle in the same manner. The first detection unit 20a does not detect the ground fault current. Further, the ground fault current detector 16 on the downstream side of the ground fault location does not detect the ground fault current. Therefore, as shown in FIG. 17, in the ground fault current detector 16 provided in the lamp 3 upstream of the ground fault of the distribution line 4, the display 40 blinks. This makes it possible to easily identify the ground fault location generated in the distribution line 4.

In addition, the ground fault current detector 16 includes a reset unit 86 that resets the notification unit 21 whose display has been changed after a predetermined time. The reset unit 86 uses a timer IC, and when a set time elapses, a reset signal is sent to each reset switch 87 provided for each changeover switch 62 connected to the two detection units 20a and 20b. Is output.

When the notification switch 41 is turned on, the power supply unit 26 operates, and the drive unit 60 is energized, the reset unit 86 is also energized. With this as a trigger, the timer in the reset unit 86 is started. When a set time, for example, 8 hours has elapsed, the reset unit 86 outputs a reset signal. The reset signal turns on the reset switch 87, energizes the reset coil 64, and puts the changeover switch 62 in a dormant state. The power supply to the drive unit 60 is interrupted and the display 40 is turned off. In this way, the lit display 40 is automatically turned off, the consumption of the battery 25 can be suppressed, and the time and effort of resetting a large number of ground fault current detectors 16 can be saved.

The present invention is not limited to the above embodiment, and it goes without saying that many modifications and changes can be made to the above embodiment within the scope of the present invention. For example, a varistor may be used as the limiting unit 23. Further, the battery 25 may be a solar cell and a secondary battery may be provided. The secondary battery is charged by the solar cell, and power is supplied from the secondary battery to the display unit 40 when a ground fault is detected.

In the ground fault current detector 16 of the first embodiment, the power from the battery 25 is directly supplied to the notification unit 21, and the power supply from the battery 25 is normally cut off, and when the ground fault is detected. Alternatively, power may be supplied from the battery 25.

In the ground fault current detector 16 of the second and fourth embodiments, when a ground fault is detected, the indicator 40 made of an LED may be turned on instead of blinking. Alternatively, the color of emitted light may be changed. Further, as the confirmation unit 70, the lid 32 of the illumination column 15 may be a lid made of a translucent material so that the light emitted from the display 40 is transmitted.

The ground fault current detector 16 of each embodiment may be provided in the illumination lamp 3 of the tunnel illumination equipment. As shown in FIG. 18, the illumination lights 3 are installed on the side walls on both sides of the tunnel 90, and the distribution line 4 is installed on the rack 91 attached to the side walls. The ground fault current detector 16 is provided for each illuminating lamp 3 and is installed in the rack 91. In this ground fault current detector 16, a confirmation window 92 is formed in the case 14, and the state of the display 40 can be visually recognized from the outside through the confirmation window 92. When a ground fault occurs in the tunnel 90, it may take time from the detection of the ground fault to the restoration work. Therefore, a magnetic reversal display that does not consume power during display is suitable for the display 40.

3 Lighting Light 4 Distribution Line 14 Joint Box 15 Lighting Pillar 16 Ground Fault Current Detector 20 Detection Section 21 Notification Section 22 Monitoring Section 23 Restriction Section 25 Battery 26 Power Supply Section 40 Indicator 41 Notification Switch 50 Capacitor 51 Changeover Switch 60 Drive Section 62 Changeover switch 70 Confirmation unit 84 Flashing unit 86 Reset unit

Claims (5)

It is a ground fault current detector provided for each of a plurality of lamps connected to a common distribution line, and a detection unit that detects an abnormal current flowing in the distribution line and a display when a ground fault current occurs A notification unit that changes and notifies, and determines whether the input voltage of the input abnormal current detection value and the input time of the input voltage are ground fault currents based on the input voltage threshold and the delay time with respect to the input time. Abnormal current detection to the monitoring unit to protect the monitoring unit by absorbing the lightning surge voltage and protect the monitoring unit by absorbing the lightning surge voltage when the ground fault current is detected and the abnormal current detection to the monitoring unit With a limiting unit that limits the input voltage of the value,
The input voltage is limited to a constant voltage determined by the set voltage of the limiter, and the set voltage is a voltage that limits the input voltage of the abnormal current detection value due to winter lightning to be lower than the input voltage threshold before reaching the delay time. If the value is set to a value larger than the input voltage threshold value, and the monitoring unit confirms that the abnormal current is a ground fault current, the monitoring unit outputs a drive signal, and the notification unit outputs the drive signal from the monitoring unit. A ground fault current detector characterized by changing the display and holding the changed state. A battery for operating the notification unit is provided, the monitoring unit operates by an abnormal current detected by the detection unit, the notification unit is switchable between a normal display state and an abnormal display state, and the notification unit is a battery. The ground fault current detector according to claim 1, wherein the normal display state is switched to the abnormal display state by using the electric power of, and the abnormal display state is maintained. A power supply unit that temporarily stores the power supplied from the battery and supplies the stored power to the notification unit is provided. The ground fault current detector according to claim 2, wherein the alarm unit is powered to operate. As the detection unit, a first detection unit that detects a ground fault current that is generated in an illumination lamp and a second detection unit that detects a ground fault that is generated in a distribution line that connects adjacent illumination lamps are provided. The unit notifies the occurrence of a ground fault current by light emission, and the light emission when the first detection unit detects it and the light emission when the second detection unit detects it are different. The ground fault current detector described in any one. The ground fault current detector according to any one of claims 1 to 4, further comprising a reset unit that resets the notification unit whose display is changed after a predetermined time.

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