JPH0353182Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is equipped with a manually reset type magnetic reversal display device that detects and displays ground fault currents that occur due to damage and deterioration of distribution equipment such as power distribution equipment and power cables. The present invention relates to a fault current detection indicator, and more particularly to a display recovery structure of an accident detection indicator that returns the fault display to its original steady state after a magnetic reversal display device has displayed the fault.

Conventional technology Conventionally, display devices that display a ground fault when a ground fault occurs, for example, when the insulation of a power distribution cable deteriorates when it is attached to a ground wire, have been installed in the coil of a solenoid when a ground fault current flows. It has been proposed that the display member is moved to the display position by exciting the plunger to attract the plunger and disengaging the plunger from the display member.

However, in this type of display device, in order to return the display member from an accident display to a normal display, the display member and the plunger must be engaged again, which is a very troublesome operation.

Purpose of the invention This invention was made by focusing on the above-mentioned problem, and is a display device for fault current detection that can easily restore the display device to a normal display after displaying an accident display. The purpose is to provide a return structure.

Structure of the invention This invention is a fault current indicator equipped with a magnetic reversal display device that displays an accident by rotating a disk in reverse when a fault current flows. A return lever that moves close to the device is arranged, and a magnet is attached to the return lever to reverse the disk from an accident display to a normal display.

Embodiment Hereinafter, an embodiment in which this invention is embodied in a ground fault indicator I for indicating the passage of fault current in power cables and distribution equipment will be described with reference to FIGS. 1 to 9.

In FIG. 1, frame 1 of ground fault indicator I is
It is formed into a reverse channel shape in cross section by a support plate portion 1a and a pair of side plate portions 1b which are bent at right angles from both sides of the support plate portion 1a. Same frame 1
A cutout groove 2 is provided at the lower end of the support plate portion 1a.
A notch is formed in a U-shape, and locking pieces 3 are formed on both sides of the notch groove 2 to protrude inward from each other, and the upper part of the notch groove 2 has a width narrower than that of the notch groove 2. A formed insertion groove 4 is provided. Furthermore, a through hole 5 is provided in the upper part of the support plate portion 1a of the frame 1.
is transparent.

A current transformer 6 is arranged on the back side of the support plate portion 1a of the frame 1. That is, in the current transformer 6, a hole 7 formed in the center around which the primary winding 6a and the secondary winding are wound is arranged corresponding to the through hole 5, and the hole 7, the through hole 5, It is tied to the support plate 1a by a string 8 wound through the insertion groove 4 and the upper end of the support plate 1a.

In the frame 1, mounting holes 9 are formed through the lower portions of both side plate portions 1b so as to face each other. A box-shaped transparent display case 10 is disposed between both side plate portions 1b of the frame 1. That is, the display case 10 has a second display window 10a.
As shown in FIGS. 3 and 3, locking step portions 11 are protruded from both sides thereof, and a mounting shaft 12 protruding from the side surfaces of the locking step portions 11 is inserted into and supported by the mounting hole 9. It is attached by this. The display case 10 is positioned by the side portions of the locking steps 11 engaging with the locking pieces 3 so as to protrude obliquely forward and downward through the notch grooves 2.

As shown in FIG. 3, a control circuit board 13 is adhesively fixed to the upper end of the display case 10 and is arranged to extend diagonally downward and rearward. A magnetic reversal display device 14 is installed inside.

A terminal 15 extending downward is fixed to one side plate portion 1b of the frame 1 by a plurality of rivets 16. A connecting piece 17 made of insulating synthetic resin extending upward is attached to the terminal 15 by the rivet 16, and the upper end of the connecting piece 17 is spaced apart from the frame 1 and the one terminal 15. The arranged terminals 18 are connected to multiple rivets 1
9, and its upper end extends upward. Both ends of the primary winding 6a of the current transformer 6 are connected to both terminals 18 and 15 by screws 20, respectively.

Around the frame 1, the current transformer 6, the control circuit board 13, the terminals 15 and 18, and the display case 10, except for the upper end surface of the terminal 18, the lower end of the terminal 15, and the display window 10a of the display case 10. A mold portion 21 made of a synthetic resin having excellent weather resistance and insulation properties, such as polyurethane, is formed to cover them.

The mold part 21 is formed into a truncated quadrangular pyramid shape so that it becomes wider toward the rear surface thereof, and protective walls 22 are provided on both sides of the upper surface thereof to protrude along the vertical direction. A return lever 23 is rotatably pivoted between the central portions of the protective wall 22.
3 is always biased by a coil spring 24 so as to be in the state shown in FIG. A magnet 25 is attached to the back surface of the return lever 23.
Further, a pair of band holes 26 are provided near the upper portions of both of the protection walls 22, through which a mounting band (not shown) can be inserted when the display device I is mounted on a utility pole or the like.

Next, the control circuit provided on the control circuit board 13 will be explained with reference to FIG.

The primary winding of the current transformer 6 is connected in series via both terminals 15 and 18 to a grounding wire 27 of a power cable or power distribution equipment (not shown). A full-wave rectifier 28 is connected to both terminals of the secondary winding of the current transformer 6 via a choke coil L. Note that Z is a surge absorber connected between both terminals on the secondary side of the current transformer 6. Same full wave rectifier 2
A display section 14 and a thyristor SCR as a switching element are connected in series to both the positive and negative terminals of the device 8. This thyristor SCR has an anode connected to the display section 14 and a cathode connected to the negative terminal of the full-wave rectifier 28.

A capacitor C for charge storage is connected between the positive and negative terminals of the full-wave rectifier 28, as well as a resistor RO for discharging the capacitor, a Zener diode ZD as a thyristor temperature compensation element, and a gate voltage application. A series circuit of a resistor R1 and a resistor R2 is connected. Note that the resistor R1 is not necessarily required, and if the resistor R1 is omitted, the resistance value of the resistor R2 may be set so as to be equal to or higher than the gate trigger voltage of the thyristor SCR when the Zener diode ZD is conductive.

The thyristor is connected to the positive terminal of the resistor R2.
The gate terminal of SCR is connected.

The Zener diode ZD is designed not to conduct unless a Zener voltage or higher is applied, and the Zener voltage is applied to the thyristor.
It is set so that a sufficient gate voltage is applied to the gate terminal to turn on the SCR even when the temperature is low, and the resistors R1 and R2 are set so that the Zener diode ZD conducts and the gate voltage supplied to the thyristor SCR is required when the temperature is low. The resistance value is set to be equal to or higher than the gate trigger voltage.

To explain the display section 14, this display section 1
Reference numeral 4 denotes a magnetic reversal display device, in which a disk 29 whose both ends are magnetized to N and S poles is rotatably supported around a rotating shaft 30, and a round bar-shaped stator 31 is connected to the S of the disk 29. Magnetic pole part 3 corresponding to the pole
2a and the magnetic pole part 3 corresponding to the N pole of the disk 29
2b. Note that the stator 31 is preferably formed of a material with low coercive force. Between the magnetic pole parts 32a and 32b, there is a coil connected to the connection terminal of the display part so that the magnetic pole parts 32a and 32b are magnetized with the same polarity as the magnetic poles at both ends of the disk 29 in the state shown in FIG. 33 is wound.

Front surface 34a and back surface 34b of the disk 29
Labels of mutually different colors (in this embodiment, the front side 34a is black and the back side 34b is red) are displayed.

When a detection current flows through the coil 33, the magnetic pole portion 32a becomes the S pole, as shown in FIG.
The magnetic pole portion 32b is magnetized to the north pole, and the disk 29 is reversely rotated so that its north pole faces the magnetic pole portion 32a (south pole) and its S pole faces the magnetic pole portion 32b (north pole). A label attached to the back surface 34b is displayed to the outside.

Furthermore, when the return lever 23 is rotated to the position shown by the chain line in FIG. 5, the display section 14 easily reverses the disk 29 by the magnet 25 attached to the return lever 23, and the normal position shown in FIG. It is now possible to return to the display state.

In the display device of this embodiment, the indicator on the surface 34a of the disk 29 initially faces outward to indicate a steady state, as shown in FIG.

The operation of the display device I configured as described above will be explained.

Now, the display device I is attached to a telephone pole (not shown) with a mounting band (not shown), and terminals 15 and 18 are connected to a grounding wire 27 provided on a power cable and power distribution equipment (not shown). .

When a ground fault current flows through the grounding wire 27 due to deterioration of the power cable (not shown) in this installed state, a transformed current is outputted by the current transformer 6.
The transformed current charges the capacitor C after being rectified by the full-wave rectifier 28.

When the capacitor C is charged and the voltage increases, and becomes higher than the Zener voltage of the Zener diode ZD, and the Zener diode ZD becomes conductive, the capacitor voltage is divided between the resistor R1 and the resistor R2, and the voltage across the resistor R2 is applied to the thyristor. SCR gate,
Applied across the cathodes.

When a sufficient gate voltage is applied to the thyristor SCR, the thyristor SCR turns on and becomes conductive. Then, the charged capacitor C is discharged and current flows to the display section 14.

When a current flows through the coil 33 of the display section 14,
As shown in FIG. 9, the magnetic pole part 32a is magnetized to the S pole, and the magnetic pole part 32b is magnetized to the N pole. (pole).
As a result, the mark attached to the back surface 34b of the disk 29 is displayed to the outside to indicate a ground fault accident.

By viewing the mark on the back surface 34b from below, it can be determined that a ground fault has occurred in the grounding wire 27.

After the ground fault point has been discovered as described above, in order to restore the display, move the return lever 23 from the state away from the magnetic reversal display device as shown in FIG. 5 to the state shown by the chain line. coil spring 24
Rotate against. Then, the magnet 25 of the return lever 23 approaches the magnetic reversal display device, so the magnet 25
The disk 29 is reversed by the magnetic force of 5 and returns to its original state, and is ready to respond to the next ground fault.

Note that, when the operating force is released, the return lever 23 returns to its original state due to the biasing force of the coil spring 24.

Effects of the device As detailed above, this device places a return lever that can be operated with a single touch near the porcelain reversing display device that displays an accident, thereby changing the display device that once displayed an accident display to a steady display. This is an excellent invention for industrial use because it allows the work of returning to the previous state to be easily carried out and therefore has the effect of improving work efficiency.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts of a display device according to an embodiment of this invention, excluding the mold part, Fig. 2 is a front view of the main parts, also excluding the mold part, and Fig. 3 is a side view of the main parts. 4 is a front view of the entire display device, FIG. 5 is a partially cutaway side sectional view, FIG. 6 is a bottom view of the entire display device, and FIG. 7 is a control circuit of the display device. FIG. 8 is a perspective view showing the display section, and FIG. 9 is a perspective view similarly showing the function of the display section. 1...Frame, 6...Current transformer, 10...
Display case, 13... Control circuit board, 14...
Display section, 15, 18...Terminal, 21...Mold section, 23...Return lever, 25...Magnet, 26...
... band hole, 27 ... ground wire, 28 ... full wave rectifier, 29 ... disk, 30 ... rotation axis, 31 ...
...Stator, 33...Coil, ...Indicator,
SCR...Thyristor, R0, R1, R2...Resistor, C...Capacitor, ZD...Zener diode.

Claims (1)

[Claims for Utility Model Registration] 1. In a fault current indicator equipped with a magnetic reversal display device that displays an accident by rotating a disk in reverse when a fault current flows, a similar device is provided near the magnetic reversal display device. Display restoration of a fault current detection display, characterized in that a return lever that moves close to the magnetic reversal display device is arranged, and a magnet is attached to the return lever to reverse the disk from an accident display to a normal display. structure. 2. The display return structure for a fault current detection display according to claim 1, wherein the return lever is rotatably pivoted to the front surface of the fault current detection display. 3. The fault current detection display according to claim 1, wherein the return lever is attached with a spring that always biases the return lever in a direction away from the magnetic reversal display device. Display return structure. 4. The display return structure for a fault current detection indicator according to claim 1 or 2, wherein the magnet is attached to the back surface of the return lever.