JPH053611A - Forced short-circuit grounding device - Google Patents

Abstract

PURPOSE:To make the damage degree of an electric apparatus smaller and to prevent reshort-circuiting by an arc, at the time of a short circuit fault inside the apparatus. CONSTITUTION:A short-circuiting conductor 7 to which force in the direction of short-circuiting between different phase electrodes of an apparatus is applied, is moved in the direction that the different phase electrodes are short-circuited and grounded, by utilizing the phenomenon that an unfastening member 9 made of a shape memory alloy is deformed by the heat of an arc produced inside the apparatus at the time of a short circuit fault.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced short-circuit grounding device, and more specifically, when a short circuit occurs between electrodes of different phases in an equipment box or between an electrode and an equipment box, the electrodes of different phases are forcibly short-circuited and grounded. The present invention relates to a forced short-circuit grounding device for an electric device that minimizes the occurrence of an arc due to this short circuit and minimizes damage to the device during a short-circuit accident.

[0002]

2. Description of the Related Art When an electric device such as a switch using air or insulating gas as an insulating medium is short-circuited due to an internal failure and an arc is generated, the arc increases the pressure in the device box and deforms the device box. Then, a high temperature gas is released to the outside or it explodes. Therefore, a pressure relief valve or the like is provided in advance on the side wall of the equipment, and this pressure relief valve is deformed or operated in accordance with an increase in the internal pressure to prevent the equipment box from being deformed or exploding.

[0003]

However, when the arc generated inside the electric equipment continues until the breaker on the power source side of the equipment breaks off, a considerable amount of high temperature gas is generated,
In addition, the equipment may be damaged, and the hot gas released outside the equipment may cause a disaster to the public. In addition, in the system of the electric power company, there is a case where power is retransmitted to a device in which an internal short-circuit failure occurs, and if a short circuit occurs and an arc occurs at this time as well, the probability of causing a public disaster increases. Therefore, it is an object of the present invention to provide a forced short-circuit grounding device which, when a short circuit occurs in an equipment box and an arc is generated, quickly stops this arc and also prevents the subsequent arc generation.

[0004]

In order to achieve the above-mentioned object, the forced short-circuit grounding device of the present invention includes a short-circuit conductor which is biased in the direction of the short-circuit position for short-circuiting electrodes of different phases, and the short-circuit conductor. A locking member that locks at the short-circuited position and a tripping member that disengages the locking member from the locking position of the short-circuit conductor are arranged in the equipment box, and the short-circuited conductor is connected to the ground potential. The tripping member is deformed due to a temperature rise in the equipment box due to the short circuit between the different-phase electrodes or between the electrodes and the equipment box in the equipment box to trip the locking member, and the elastic member short-circuits the conductor. Is configured to be moved to the short-circuit ground position. A shape memory alloy can be used as the trip member.

[0005]

When the temperature inside the equipment box rises due to a short circuit between the different-phase electrodes or between the electrodes and the equipment box, the trip member is deformed and the short-circuit conductor is unlocked, and the short-circuit conductor short-circuits between the different-phase electrodes. It is possible to extinguish the arc by moving in the direction of the short circuit and short-circuiting and grounding between the electrodes of different phases.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, an example in which the forced short-circuit grounding device of the present invention is used for a gas switch is shown in FIGS. The switch 1 includes a contact 3 held by a bushing 2 and a blade 4 for three phases in a closed box, and a forced short-circuit grounding device 5 close to the contact 3.
Is equipped with. The forced short-circuit grounding device 5 is provided in the center of the short-circuit conductor 7 that is biased in the direction of the short-circuit position for short-circuiting the contacts 3 by the spring 6 that is an elastic member, and places the short-circuit conductor 7 in the non-short-circuit position. It comprises a locking member 8 for locking, a trip member 9 for removing the locking member 8 from the locking position of the short-circuit conductor 7, and a guide 12 for restricting the movement of the short-circuit conductor 7. The short-circuit conductor 7 includes a short-circuit contact 10 that contacts the corresponding contact 3, and a connecting plate 71 that locks the locking auxiliary plate 72 and the short-circuit conductor 7 with the locking member 8.
The tripping member 9 is fixed to the switch case 11 and the locking member 8 by using a shape memory alloy whose shape is shortened in the vertical direction of FIG. 1 when the temperature rises. In the forced short-circuit grounding device 5 configured as described above, the short-circuit conductor 7 is normally held at the non-short-circuited position by the locking member 8 as shown in the figure. An arc is generated due to a short circuit between the different-phase electrodes or between the electrodes and the switch case 11, and the switch 1
When the internal temperature rises, the shape of the trip member 9 made of a shape memory alloy changes, and the locking member 8 moves downward in FIG. As a result, the locked state between the locking auxiliary plate 72 and the connecting plate 71 is released, the short-circuit conductor 7 moves along the guide 12 by the force of the spring 6, and the contact point 3 and the short-circuit contactor 10 come into contact with each other to cause a different phase. The electrodes are short-circuited and grounded through a guide 12 made of a conductor. The arc is extinguished because the different-phase electrodes are metallically short-circuited and grounded. Here, an example of using a shape memory alloy as the trip member and tripping the locking member is shown, but a spring biased in the direction of tripping the locking member is locked using a bimetal to break the switch. It is also conceivable that the temperature rising bimetal inside 1 is deformed, and the locking member 8 is disengaged and the locking member 8 is tripped by the force of the biased spring.

[0007]

As described above, in the forced short-circuit grounding device for electric equipment of the present invention, the short-circuit conductor urged by the elastic member is locked by the locking member so that the different-phase electrodes or the electrodes and the equipment outer casing are connected to each other. When a short circuit occurs, a tripping member that moves the locking member to the short-circuiting conductor's short-circuiting position is provided, so if the temperature inside the device rises due to a short circuit between the different-phase electrodes or between the electrode and the equipment box, the tripping member will deform and short-circuit. The conductor is unlocked,
The short-circuit conductor moves in the direction of short-circuiting between the different-phase electrodes to short-circuit and ground the different-phase electrodes to extinguish the arc. This allows
Even if a short circuit occurs between electrodes of different phase or between the electrode and the equipment box, the arc can be extinguished quickly, the damage of the equipment at the time of a short circuit failure can be minimized, and the re-short circuit due to the arc can be prevented.

[Brief description of drawings]

FIG. 1 is a plan sectional view showing an embodiment of the present invention.

FIG. 2 is a side sectional view showing an embodiment of the present invention.

[Explanation of symbols]

1 switch 2 bushings 3 contacts 4 blades 5 Forced short-circuit grounding device 6 spring 7 Short-circuit conductor 8 locking member 9 Tripping member 10 Short-circuit contact 11 switch case 12 guides 71 Connection plate 72 Locking auxiliary plate

Claims (2)

[Claims] 1. A short-circuit conductor connected to a ground potential, an elastic member for urging the short-circuit conductor in a direction of short-circuiting between different-phase electrodes, and a locking member for locking the short-circuit conductor in a non-short-circuited position. A tripping member for removing the locking member from the locking position is installed in the equipment box, and the tripping member is deformed due to a temperature rise in the equipment box due to a short circuit in the equipment box, and the locking member is removed. A forced short-circuit grounding device, which is configured to be tripped and to move the short-circuit conductor to a short-circuit position. 2. The forced short-circuit grounding device according to claim 1, wherein the trip member is a shape memory alloy.