Circuit breaker test changeover switch, lead wire connection tool, circuit breaker test system, and circuit breaker test method

Abstract

To provide a circuit breaker test changeover switch, a lead wire connection tool, a circuit breaker test system, and a circuit breaker test method that enables stable circuit breaker testing using a grounding device connected to a main circuit.SOLUTION: A changeover switch 10 includes grounding device connecting means 13 connected to a main circuit and to which a grounding device for grounding the main circuit can be detachably connected, tester connecting means 14 connected to the grounding device connecting means 13 via a lead wire 16 and to which a main circuit lead wire 4a connected to a circuit breaker tester can be detachably connected, a switch body 12 whose primary side terminal is connected to the grounding device connecting means 13 via a lead wire 17 and can be switched between an on state and an open state, and a grounding terminal 15 connected to the secondary side terminal of the switch body 12 via a lead wire 18 and to which a grounding lead wire 3 is detachably connected.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a changeover switch for circuit breaker testing, a lead wire connecting jig, a circuit breaker testing system, and a circuit breaker testing method. [Background technology]

[0002] In substations and the like, circuit breakers (CBs) are installed to interrupt current flowing through main circuits, and circuit breaker tests (CB tests) such as switching characteristic tests are performed on these circuit breakers. In the CB test, it is necessary to connect a CB tester to a pair of main circuits supported by the bushings of the circuit breaker, and for example, a worker climbs onto the circuit breaker to connect the lead wires to the main circuits. Since such high-altitude work places a burden on workers, there is a demand for CB tests that can be performed without working at high altitudes. For example, Patent Document 1 discloses a method of electrically connecting a main circuit and a CB tester using an earth hook with a hook at the tip for hooking onto the main circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-8226 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the method of Patent Document 1, a current transformer with a winding wound around a gapped annular core is placed so that the grounding lead of the grounding device passes through it, and a voltage is applied to the winding to generate a test current in the grounding lead. For this reason, the test current cannot be directly supplied to the grounding lead of the grounding device, and it is difficult to control the characteristics of the test current supplied to the grounding lead. In addition, it is necessary to hold the current transformer so that it does not shift relative to the grounding lead. For this reason, there is a problem that it is difficult to stably perform the CB test.

[0005] The present invention has been made against this background, and aims to provide a circuit breaker test changeover switch, a lead wire connecting jig, a circuit breaker test system, and a circuit breaker test method that enable stable circuit breaker testing using a grounding device connected to a main circuit. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a changeover switch for circuit breaker testing, a grounding device connecting means connected to the main circuit and capable of detachably connecting a grounding device for grounding the main circuit; a tester connection means connected to the grounding device connection means via a lead wire, to which a lead wire connected to a circuit breaker tester can be detachably connected; a switch body having a primary terminal connected to the grounding device connecting means via a lead wire and capable of being switched between an ON state and an OFF state; a ground terminal connected to the secondary terminal of the switch body via a lead wire and to which a ground lead wire is detachably connected; Equipped with. Effect of the Invention

[0007] According to the present invention, it is possible to provide a changeover switch for circuit breaker testing, a lead wire connecting jig, a circuit breaker testing system, and a circuit breaker testing method that enable stable circuit breaker testing using a grounding device connected to a main circuit. [Brief description of the drawings]

[0008] [Figure 1] 2 is a diagram showing a configuration of a test circuit in a circuit breaker test according to the first embodiment of the present invention. FIG. [Diagram 2] FIG. 2 is a diagram showing a configuration of a changeover switch according to the first embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram showing a circuit configuration of a changeover switch according to the first embodiment of the present invention. [Figure 4] 4 is a flowchart showing the flow of a circuit breaker testing method according to the first embodiment of the present invention. [Diagram 5] FIG. 11 is a diagram showing a configuration of a test circuit in a circuit breaker test according to a second embodiment of the present invention. [Figure 6] FIG. 11 is a perspective view showing a configuration of a lead wire connecting jig according to a second embodiment of the present invention. [Figure 7] 7 is an enlarged view of a portion of the lead wire connecting jig in FIG. 6. [Figure 8] 10 is a flowchart showing the flow of a circuit breaker testing method according to a second embodiment of the present invention. [Figure 9] FIG. 13 is a diagram showing a configuration of a test circuit in a circuit breaker test according to a modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a changeover switch for circuit breaker testing, a lead wire connecting jig, a circuit breaker testing system, and a circuit breaker testing method according to embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or equivalent parts are denoted by the same reference numerals.

[0010] (Embodiment 1) A changeover switch for circuit breaker testing, a circuit breaker testing system, and a circuit breaker testing method according to embodiment 1 will be described. In embodiment 1, a case will be described in which a grounding device for grounding the main circuit is attached to each of the main circuits supported by the bushings of the circuit breaker before the circuit breaker inspection work. Since the main circuit needs to be worked on to configure a CB test circuit during the circuit breaker inspection work, the main circuit connected to the circuit breaker needs to be grounded in advance as a safety measure.

[0011] The circuit breaker testing system according to the first embodiment is a system that performs a CB test using a CB tester connected to each of a pair of main circuits supported by a bushing of the circuit breaker. The CB test is a test to check whether the time required for breaking and closing the circuit breaker satisfies a standard value set for each circuit breaker. Separate disconnecting switches are electrically connected to the circuit breaker via each main circuit, and the CB test is performed by dividing the electric circuit between the disconnecting switches into a power failure range by opening each disconnecting switch after breaking the current of the main circuit using the circuit breaker.

[0012] As shown in Figure 1, the circuit breaker testing system 1 comprises a pair of grounding devices 2 attached to a pair of main circuits supported by the bushings of the circuit breaker and each grounded, a changeover switch 10 connected to the primary side grounding device 2 and switching between an on state in which the main circuits are grounded by the primary side grounding device 2 and an open state in which the CB tester 4 and the main circuits are electrically connected to each other, a grounding lead wire 3 connected to the changeover switch 10, and a CB tester 4 connected to the changeover switch 10 and the secondary side grounding device 2 and performing an operation test of the circuit breaker.

[0013] The changeover switch 10 and the CB tester 4 are connected via a main circuit lead wire 4a, and the CB tester 4 is connected to a ground wire via a main circuit lead wire 4b. The ground wire is, for example, a ground wire connected to an underground grounding network or a ground electrode. The main circuit lead wire 4b connected to the CB tester 4 and the lead wire 2c of the grounding device 2 are separately grounded, and the main circuit lead wire 4b and the lead wire 2c are mutually conductive via the ground wire. Since the main circuit lead wire 4b and the lead wire 2c are not directly connected, the circuit configuration can be simplified.

[0014] In FIG. 1, each of the earthing devices 2 and each of the main circuit lead wires 4a, 4b connected to the main circuit supported by the bushing of the circuit breaker are shown with one each omitted, but since the main circuit is a three-phase circuit through which three-phase AC flows, in reality three each are provided.

[0015] The grounding device 2, also called a discharge rod or earth hook, is a device that is connected to the main circuit by an operator and grounds the main circuit via a lead wire. The grounding device 2 is connected to the main circuit before the inspection of the circuit breaker in order to reliably discharge the residual charge in the main circuit after a power outage and to protect the operator from high voltage in the unlikely event that high voltage is mistakenly applied to the main circuit. The grounding device 2 is heavy due to its high safety performance, so installing and removing it is a burden for the operator.

[0016] The grounding device 2 includes a rod-shaped member 2a that can be held by an operator, a conductive hook 2b that is provided at the tip of the rod-shaped member 2a and configured to be hooked onto the main circuit, and a lead wire 2c that is electrically connected to the conductive hook 2b and grounds the main circuit via a means such as a grounding wire installed on the ground. The rod-shaped member 2a is made of an insulating material so that the operator does not get an electric shock, and the conductive hook 2b and the lead wire 2c are formed so that they will not melt due to heat even if a large current flows through them. The conductive hook 2b is formed so that it can be tightened with a screw, for example, to prevent it from falling off the main circuit.

[0017] Since bare wires are used in the main circuit of the substation, an operator can simply grasp the rod-shaped member 2a and hook the conductive hook 2b onto the main circuit to obtain an electrical connection between the main circuit and lead wire 2c, and the main circuit can be grounded via lead wire 2c.

[0018] The secondary-side grounding device 2 grounds the secondary-side main circuit of the circuit breaker and is always used as the common side. On the other hand, the primary-side grounding device 2 grounds the primary-side main circuit of the circuit breaker when the switch body of the changeover switch 10 is turned on. Also, the primary-side grounding device 2 electrically connects the primary-side main circuit to the CB tester 4 when the switch body of the changeover switch 10 is opened. At this time, a test circuit is formed between the pair of main circuits, the circuit breaker, and the CB tester 4.

[0019] As shown in Fig. 2, the changeover switch 10 includes a housing 11, a switch body 12 attached to the housing 11, a grounding device connection means 13 attached to the housing 11, electrically connected to the primary terminal of the switch body 12, and capable of detachably connecting the lead wire 2c of the grounding device 2 connected to the main circuit, a tester connection means 14 attached to the housing 11, electrically connected to the grounding device connection means 13, and capable of detachably connecting to the main circuit lead wire 4a connected to the CB tester 4, and a ground terminal 15 attached to the housing 11, electrically connected to the secondary terminal of the switch body 12, and to which the grounding lead wire 3 is detachably connected. The grounding device connection means 13 and the tester connection means 14 are electrically connected to each other via a lead wire 16, and the switch body 12, the grounding device connection means 13, and the ground terminal 15 are electrically connected to each other via lead wires 17 and 18, respectively.

[0020] The housing 11 is configured such that, for example, two box-shaped cases 11a and 11b are connected by a hinge 11c, and the two cases 11a and 11b are arranged side by side in the open state. Inside the housing 11, the components constituting the changeover switch 10 are attached. Specifically, the switch body 12 is attached to one case 11a, and other components are attached to the other case 11b. When the housing 11 is open, the components constituting the changeover switch 10 are exposed to the outside, and when the housing 11 is closed, the components constituting the changeover switch 10 are housed inside.

[0021] The switch body 12 is a device that simultaneously switches between breaking and grounding a three-phase circuit. The switch body 12 is, for example, a knife switch with a cover (three-pole knife switch). The knife switch has a knife-shaped blade and a blade receiver that receives the knife-shaped blade. The switch body 12 has a lever 12a that can be operated manually and switches between breaking and grounding. It is preferable that the front and back of the lever 12a are provided with markings that allow an operator to determine whether the lever 12a is in the "grounded" position or the "tested" position when the lever 12a is tilted to each side.

[0022] The grounding device connection means 13 includes three terminals 13a, 13b, and 13c for detachably connecting the three lead wires 2c of each grounding device 2. The terminals 13a, 13b, and 13c are L-shaped metal members arranged at positions spaced apart from each other. The lead wires 2c are detachably connected to the terminals 13a, 13b, and 13c by fastening the fasteners provided at the ends of the lead wires 2c.

[0023] The tester connection means 14 is, for example, a terminal block in which a plurality of terminals are combined with an insulating component. The tester connection means 14 has three terminals 14a, 14b, and 14c that detachably connect the three main circuit lead wires 4a connected to the CB tester 4. The three terminals 14a, 14b, and 14c are each provided with a connector, and each connector is connected to a connector provided on each main circuit lead wire 4a.

[0024] The ground terminal 15 is a terminal to which the ground lead wire 3 is detachably connected, and which grounds the switch body 12 via the ground lead wire 3. The ground terminal 15 is detachably connected by fastening a fastener provided at the end of the ground lead wire 3.

[0025] Hereinafter, the circuit arrangement of the changeover switch 10 according to the first embodiment will be described with reference to FIG. 3. In FIG. 3, solid lines indicate lead wires, and circles indicate terminals. The terminals 13a, 13b, and 13c of the earthing device connection means 13 are connected to the terminals 14a, 14b, and 14c of the tester connection means 14 via separate lead wires 16. The three terminals 13a, 13b, and 13c are connected to the three primary main circuits via the respective lead wires 2c, and the three terminals 14a, 14b, and 14c are connected to the three terminals of the CB tester 4 via the respective main circuit lead wires 4a. The terminals 13a, 13b, and 13c of the earthing device connection means 13 and the terminals 14a, 14b, and 14c of the tester connection means 14 constitute the primary terminals of the changeover switch 10.

[0026] Moreover, each terminal 13a, 13b, 13c of the earthing device connection means 13 is connected to each terminal provided on the primary side of the switch body 12 via a separate lead wire 17. Each terminal provided on the secondary side of the switch body 12 is connected to one ground terminal 15 via a separate lead wire 18. The ground terminal 15 is connected to a ground wire installed on the ground via a grounding lead wire 3, and constitutes a secondary side terminal of the changeover switch 10. Since the changeover switch 10 has the above circuit arrangement, when the switch body 12 is turned on, all three phases of the main circuit are grounded, and when the switch body 12 is turned off, all three phases of the main circuit are disconnected from the ground and connected to the CB tester 4.

[0027] Returning to Fig. 1, the CB tester 4 outputs a control signal to the circuit breaker while supplying a test current to the primary side of the circuit breaker, and measures the on / off of the weak current on the secondary side of the circuit breaker. The CB tester 4 is connected to the circuit breaker control unit via a control signal lead (not shown), and sends a control signal to the circuit breaker control unit to control the operation of the circuit breaker. The circuit breaker testing system 1 has the above configuration.

[0028] Next, a flow of a circuit breaker test method performed by an operator using the circuit breaker test system 1 according to the first embodiment will be described with reference to Fig. 4. In the following, it is assumed that power transmission in the main circuit has been stopped in advance.

[0029] First, the primary side terminal and the secondary side terminal of the changeover switch 10 are connected to the primary side grounding device 2 and the grounding lead wire 3, respectively, to ground the changeover switch 10 (step S1). Specifically, first, the lead wire 2c of the primary side grounding device 2 is connected to the grounding device connecting means 13 of the changeover switch 10. At this time, the lever 12a of the switch body 12 provided on the changeover switch 10 is tilted to the on side. Next, the grounding lead wire 3 is connected to the ground terminal 15, and the grounding lead wire 3 is connected to a ground wire installed on the ground, thereby grounding the changeover switch 10.

[0030] Next, the grounding device 2 is attached to each of the primary and secondary main circuits (step S2). At this time, the lead wire 2c of the secondary grounding device 2 is connected to the ground wire in advance before being connected to the secondary main circuit.

[0031] Next, the input terminal and output terminal of the CB tester 4 are connected to the ground line and the changeover switch 10, respectively (step S3). Specifically, first, the input terminal of the CB tester 4 is connected to the ground line via the main circuit lead wire 4b. Next, the output terminal of the CB tester 4 is connected to the tester connection means 14 of the changeover switch 10 via the main circuit lead wire 4a.

[0032] Next, the lever 12a of the switch body 12 is tilted to the open side to disconnect the primary main circuit and the CB tester 4 from ground (step S4), and a CB test is performed using the CB tester 4 (step S5).

[0033] After the CB test is completed, the lever 12a of the switch body 12 is returned to the on side to ground the primary main circuit and the CB tester 4 (step S6), and the CB tester 4 is removed from the changeover switch 10 (step S7). The above is the flow of the circuit breaker test method.

[0034] As described above, the changeover switch 10 according to the first embodiment includes the grounding device connection means 13 connected to the main circuit and to which the grounding device 2 for grounding the main circuit can be detachably connected, the tester connection means 14 connected to the grounding device connection means 13 via the lead wire 16 and to which the main circuit lead wire 4a connected to the CB tester 4 can be detachably connected, the switch body 12 whose primary side terminal is connected to the grounding device connection means 13 via the lead wire 17 and whose state is switched between an ON state and an OFF state, and the grounding terminal 15 connected to the secondary side terminal of the switch body 12 via the lead wire 18 and to which the grounding lead wire 3 is detachably connected. This allows a closed test circuit to be configured using the grounding device 2, so that the CB test can be easily and stably performed using the grounding device 2 connected to the main circuit.

[0035] (Embodiment 2) Next, a changeover switch for circuit breaker testing, a lead wire connecting tool, a circuit breaker testing system, and a circuit breaker testing method according to embodiment 2 will be described. In embodiment 1, a grounding device 2 is attached to each of the main circuits supported by the bushings of the circuit breaker during inspection work, whereas embodiment 2 will be described taking as an example a case in which a grounding device 2 is attached to the main circuit on the primary side of the circuit breaker during inspection work, and a grounding device 2 is not attached to the main circuit on the secondary side. The following will focus on the differences between the two.

[0036] As shown in FIG. 5, in the circuit breaker test system 1 according to the second embodiment, after the start of inspection of the circuit breaker and before the CB test is performed, the lead wire connection jig 20 is connected to the secondary main circuit of the circuit breaker. The lead wire connection jig 20 is hooked onto an electric wire that is not coated with insulation and electrically connected to the electric wire, and connects the electric wire to other equipment, for example, a ground wire or a changeover switch 10, via the lead wire. The lead wire connection jig 20 is not required to have high insulation performance or the like because it is not intended to be applied with high voltage like the grounding device 2, and each part can be made of lightweight parts. As a result, the burden on the worker in mounting and removing the lead wire is reduced. The configuration of the lead wire connection jig 20 will be described below.

[0037] As shown in FIG. 6, the lead wire connecting jig 20 comprises a rod-shaped member 21 that can be held by an operator, a cap member 22 supported on the tip of the rod-shaped member 21, a holding means 23 that is supported so as to be swivellable relative to the cap member 22 and that holds the main circuit from both sides by elastic force while hooked onto the main circuit, and is conductive so as to be electrically connected to the main circuit, and a lead wire 24 that is electrically connected to the holding means 23.

[0038] The rod-shaped member 21 includes a shaft 21a and a handle 21b that is provided on the base end side of the shaft 21a and can be held by an operator. The shaft 21a and the handle 21b are, for example, integrally formed. The shaft 21a is, for example, extendable in the longitudinal direction.

[0039] 7, the cap member 22 includes a base end member 22a formed in a cylindrical shape and attached to the tip side of the shaft 21a, and a plate-shaped tip member 22b extending from the base end member 22a to the tip side. The base end member 22a and the tip member 22b are molded integrally, for example. The cap member 22 may be a part molded integrally from plastic. The rod-shaped member 21 and the cap member 22 may be commercially available products as they are.

[0040] The gripping means 23 is made of a conductive material, for example, a metal material, and includes a plate-shaped member 23a rotatably supported by the tip member 22b, and a curved member 23b supported by the plate-shaped member 23a and sandwiching the main circuit together with the plate-shaped member 23a by elastic force.

[0041] The plate-like member 23a is in contact with the tip member 22b and is arranged so as to extend in a direction parallel to each other. A bolt 22c is inserted through a through hole of the plate-like member 23a and an insertion hole of the tip member 22b, and a nut 22d is fastened from the tip side of the bolt 22c. The plate-like member 23a is supported rotatably around the longitudinal axis L of the bolt 22c, and when the nut 22d is fastened to the bolt 22c, the tip member 22b and the plate-like member 23a are pressed against each other, and the inclination of the gripping means 23 relative to the cap member 22 can be maintained.

[0042] The bolt 22c is inserted into a through hole of a round terminal 24a to which the lead wire 24 is connected. The plate-like member 23a and the bolt 22c are electrically connected to each other, and the bolt 22c and the round terminal 24a of the lead wire 24 are electrically connected to each other. As a result, the main circuit and the lead wire 24 are electrically connected via the plate-like member 23a, the bolt 22c, and the round terminal 24a.

[0043] The curved member 23b is curved so that its free end is separated from the plate-shaped member 23a, its middle part is in contact with the plate-shaped member 23a, and the main circuit is accommodated in the space formed between the middle part and the connection end. When the main circuit guided by the inner surface of the curved member 23b passes over the middle part and moves toward the base end, the plate-shaped member 23a and the curved member 23b press the main circuit from both sides and sandwich it. The free end of the curved member 23b is preferably positioned closer to the base end of the lead wire connecting jig 20 than the base end of the plate-shaped member 23a so that the main circuit can be easily hooked.

[0044] The plate-like member 23a and the curved member 23b are in contact with each other via a hinge 23c at the tip side of the gripping means 23. A through hole is formed in each of the plate-like member 23a and the curved member 23b, and a through hole is also formed on both sides of the hinge 23c. A bolt 23d is inserted through the through hole of the plate-like member 23a and one of the through holes of the hinge 23c, and another bolt 23d is inserted through the through hole of the curved member 23b and the other through hole of the hinge 23c, and each is tightened with a nut 23e.

[0045] The plate-shaped member 23a and the curved member 23b are biased toward each other by a coil spring 23f provided on the tip side of the gripping means 23, closer to the base end than the hinge 23c. The coil spring 23f is an example of a biasing means for biasing the plate-shaped member 23a and the curved member 23b toward each other. The coil spring 23f is supported by the plate-shaped member 23a and the curved member 23b, and is guided by a bolt 23g extending in a direction intersecting the plate-shaped member 23a.

[0046] Specifically, a through hole through which a bolt 23g is inserted is formed in each of the plate-shaped member 23a and the curved member 23b, and the head of the bolt 23g contacts the outer surface of the curved member 23b, and the coil spring 23f contacts the outer surface of the plate-shaped member 23a. When a nut 23h attached to the shaft of the bolt 23g is tightened, the coil spring 23f is compressed, and the plate-shaped member 23a and the curved member 23b can be biased in a direction to approach each other. This allows the plate-shaped member 23a and the curved member 23b to maintain a state in which their intermediate portions are in contact with each other, and allows the plate-shaped member 23a and the curved member 23b to stably hold the main circuit that has passed over the intermediate portion of the curved member 23b.

[0047] Since the lead wire connecting jig 20 has the above-mentioned configuration, it can hold the gripping means 23 in a tilted state relative to the rod-shaped member 21, and can connect to the main circuit even if the main circuit stands vertically. In addition, since the gripping means 23 presses the main circuit from both sides while sandwiching it, it is possible to suppress the effect of operational vibrations on the test results of the CB test. The configuration of the lead wire connecting jig 20 has been described above.

[0048] Next, a flow of a circuit breaker test method performed by an operator using the lead wire connecting jig 20 according to the second embodiment will be described with reference to Fig. 8. In the following, it is assumed that power transmission in the main circuit has been stopped in advance.

[0049] First, steps S1 and S2 are performed, and then the lead wire connecting jig 20 is connected to the secondary main circuit (step S2A). Specifically, with the lead wire 24 connected to the ground wire, an operator grasps the handle 21b, lifts the lead wire connecting jig 20, and hooks the gripping means 23 onto the main circuit.

[0050] Next, steps S3 to S6 are carried out. After that, the CB tester 4 is removed from the ground wire and the changeover switch 10 (step S7), and the lead wire connecting jig 20 is removed from the secondary main circuit (step S8). The above is the flow of the circuit breaker test method.

[0051] As described above, the lead wire connecting jig 20 according to the second embodiment includes the rod-shaped member 21 that can be held by a user, the conductive gripping means 23 that is provided at the tip of the rod-shaped member 21 and supported swivelably relative to the rod-shaped member 21 and can grip the main circuit from both sides by elastic force, and the lead wire 24 that is electrically connected to the gripping means 23. Therefore, the CB tester 4 can be connected to the main circuit regardless of the direction in which the main circuit extends, and the electrical connection between the CB tester 4 and the main circuit can be stabilized, so that the CB test can be stably performed.

[0052] The present invention is not limited to the above-described embodiment, and the following modifications are possible.

[0053] (Modification) In the above embodiment, the grounding device 2 is used to ground the main circuit, and the lead wire 2c of the grounding device 2 is connected to the changeover switch 10, but the present invention is not limited to this. For example, a grounding device having clips attached to both ends of a lead wire may be used, and a worker may work at a height to connect one clip to the main circuit and the other clip to the changeover switch 10, thereby connecting the main circuit and the changeover switch 10 via the lead wire.

[0054] In the above embodiment, the changeover switch 10 is connected to the grounding device 2 on the primary side of the circuit breaker, but the present invention is not limited to this. For example, the changeover switch 10 may be connected to the grounding device 2 on the secondary side of the circuit breaker.

[0055] In the above embodiment, the CB tester 4 is configured as a circuit by connecting it to the ground line via the main circuit lead wire 4b, but the present invention is not limited to this. For example, the CB tester 4 may be configured as a circuit by connecting it to the lead wire 2c of the secondary side grounding device 2 that is grounded via a ground wire, or may be connected to the lead wire 24 of the lead wire connecting jig 20 that is grounded via a ground wire.

[0056] In the above embodiment, each part of the changeover switch 10 is attached to the housing 11, but the present invention is not limited to this. For example, the housing 11 may be omitted, or a plate member may be used instead of the housing 11.

[0057] In the above embodiment, the rod-shaped member 21 includes the shaft 21a and the handle 21b, but the present invention is not limited to this. For example, the handle 21b may be omitted from the rod-shaped member 21, and the worker may hold the shaft 21a.

[0058] In the above-mentioned second embodiment, the cap member 22 is provided on the tip of the rod-shaped member 21 of the lead wire connecting jig 20, but the present invention is not limited to this. For example, the cap member 22 may be omitted, and the gripping means 23 may be rotatably supported directly on the tip of the rod-shaped member 21.

[0059] In the above-mentioned second embodiment, the plate-like member 23a and the curved member 23b are connected via the hinge 23c, but the present invention is not limited to this. For example, the plate-like member 23a and the curved member 23b may be directly connected, or the plate-like member 23a and the curved member 23b may be formed integrally in advance.

[0060] In the above-mentioned second embodiment, the plate-shaped member 23a and the curved member 23b are biased toward each other by the coil spring 23f, but the present invention is not limited to this. If a sufficient elastic force can be obtained by the plate-shaped member 23a and the curved member 23b, a biasing means such as the coil spring 23f may be omitted.

[0061] In the above-mentioned second embodiment, the disconnector is connected to the secondary side of the main circuit, and the secondary side of the disconnector is grounded, but the present invention is not limited to this. For example, as shown in FIG. 9, a transformer Tr (voltage transformer) and a cubicle CUB (high voltage power receiving equipment) may be connected in this order to the secondary side of the circuit breaker. In this case, it is preferable to attach a grounding device 2 to the secondary side of the cubicle CUB for grounding, and connect a lead wire connecting jig 20 to the main circuit on the secondary side of the circuit breaker. The CB tester 4 may be connected to the grounding line via a main circuit lead wire 4b, or may be connected to the lead wire connecting jig 20.

[0062] In the above embodiment, the grounding device 2 is attached to the main circuit supported by the bushing of the circuit breaker, but the present invention is not limited to this. Depending on the circuit configuration to be inspected, the grounding device 2 may be attached to the main circuit away from the circuit breaker. For example, in an inspection of a circuit breaker that involves stopping a busbar at a multi-busbar power station, if two disconnectors A and B are connected in parallel to the main circuit on the primary side of the circuit breaker, it is advisable to attach the grounding device 2 near the A and B disconnectors. The reason for this is that it is safer to attach the ground near the inflow point of the power source.

[0063] In the above modification, it is preferable to connect the changeover switch 10 to the earthing device 2 located away from the circuit breaker, and to install the CB tester 4 near the circuit breaker and connect the changeover switch 10 and the CB tester 4 with a long main circuit lead wire 4a. This is because the CB test requires an operator to operate the CB tester 4 and check the operating status of the circuit breaker. Also, if the CB tester 4 is installed near the circuit breaker, there is no need to extend the lead wire for the control signal.

[0064] The above-mentioned embodiments are merely examples, and the present invention is not limited to these, and various embodiments are possible without departing from the spirit of the invention described in the claims. The components described in the embodiments and modifications can be freely combined. In addition, inventions equivalent to the inventions described in the claims are also included in the present invention. [Explanation of symbols]

[0065] 1 Circuit Breaker Test System 2 Grounding equipment 4. CB Tester 10. Changeover switch 11. Cabinet 12 Switch body 13 Means of grounding device connection 14 Tester connection means 15 Ground terminal 16,17,18 Lead wire 20 Lead wire connection jig 21 Rod-shaped member 23 Gripping means 24 Lead Wire

Claims

1. a grounding device connecting means connected to the main circuit and capable of detachably connecting a grounding device for grounding the main circuit; a tester connection means connected to the grounding device connection means via a lead wire, to which a lead wire connected to a circuit breaker tester can be detachably connected; a switch body having a primary terminal connected to the grounding device connecting means via a lead wire and capable of being switched between an ON state and an OFF state; a ground terminal connected to the secondary terminal of the switch body via a lead wire and to which a ground lead wire is detachably connected; A change-over switch for circuit breaker testing comprising:

2. The switch further includes a housing that can be opened and closed so that the grounding device connecting means, the tester connecting means, the switch body, and the grounding terminal are attached, and the grounding device connecting means, the tester connecting means, the switch body, and the grounding terminal are exposed to the outside when opened, and are accommodated inside when closed.

2. The changeover switch for testing a circuit breaker according to claim 1.

3. A rod-shaped member that can be held by a user; a gripping means provided at a tip of the rod-shaped member, supported to be pivotable relative to the rod-shaped member, and capable of gripping the main circuit from both sides by elastic force and having conductivity; a lead wire electrically connected to the gripping means; A lead wire connection tool comprising:

4. A changeover switch for circuit breaker testing according to claim 1 or 2; a grounding device connected to the grounding device connection means of the circuit breaker test changeover switch and to the primary side of the main circuit; a circuit breaker tester connected to the tester connection means of the circuit breaker test changeover switch; a grounding lead wire connected to the secondary terminal of the switch body provided in the circuit breaker test changeover switch; the lead wire connection jig according to claim 3, wherein a holding means is connected to a secondary side of the main circuit, and the secondary side of the main circuit is grounded via the holding means and a lead wire of the lead wire connection jig that is electrically connected to the holding means; A circuit breaker test system comprising:

5. a grounding device connected to a main circuit connected to a circuit breaker; A circuit breaker tester that performs a circuit breaker test while being connected to the circuit breaker; a changeover switch capable of switching between an ON state in which a primary terminal is connected to both the grounding device and the circuit breaker tester and a secondary terminal is grounded, and an OFF state in which the main circuit is electrically connected to the circuit breaker tester; A circuit breaker test system comprising:

6. a step of switching a changeover switch including a primary terminal connected to both a grounding device connected to a main circuit connected to a circuit breaker and a circuit breaker tester for performing a circuit breaker test on the circuit breaker, and a secondary terminal for grounding the main circuit, from an on state in which the main circuit is grounded to an open state in which the main circuit and the circuit breaker tester are electrically connected; performing a circuit breaker test using the circuit breaker tester; switching the changeover switch from the open state to the closed state; A circuit breaker test method including:

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