JPH0638315A - Switchboard - Google Patents

Abstract

PURPOSE:To protect electric machinery against damage due to arc by providing an auxiliary conductor for feeding arc on the power supply side of each branch conductor connected with a power supply conductor or for the power conductor. CONSTITUTION:Upon occurrence of arc A due to short circuit fault of power supply conductor, the arc A moves on the load side, i.e. in the direction of an auxiliary conductor 6, when viewed from an interphase arcing point between power supply branch conductors 4A, 4A for U phase and V phase, for example. The arc A does not move in the direction of power supply 3 side disconnecting section but moves to the auxiliary conductor 6 and stagnates thereat. In other words, when the auxiliary conductor 6 is fixed, arc A from the power supply 3 moves, with electromagnetic force F2, through 1X point closest to the power supply 3 and 2X point to 4X point at the tip of the arc auxiliary conductor 6 and stagnates thereat. This constitution protect power supply 3 side disconnecting section or electric machinery such as a circuit breaker against breakdown due to arc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switchboard which is improved in prevention of discharge of arcs flowing in a power bus, branch conductors and the like.

[0002]

2. Description of the Related Art If a short circuit occurs inside a switchboard, an arc will be generated, and the generated energy will damage or burn electrical equipment and insulators around it, causing a serious accident. . Therefore, it is desired to control and calm the arc, and to change the place where the arc energy is generated. As this kind of technology,
48-11534 can be mentioned. In this conventional example,
Inside the empty box where the arc generated on the common bus was installed at the end part on the side farther than the pull-in side, the transmitted arc was detonated and the influence on other boxes was suppressed.

[0003]

Therefore, by providing an empty box which is completely unnecessary as a switchboard, a wide space is required and a cost is required. In addition, no consideration is given to the possibility that the protective switch, current transformer, or the like will be damaged by the arc during a short-circuit accident.

An object of the present invention is to protect switches from arcs,
An object of the present invention is to provide a switchboard that prevents damage to electric devices such as current transformers.

[0005]

In order to achieve the above object, a switchboard according to the present invention has a plurality of branch conductors connected to a power source busbar in the switchboard and an electric device connected to each branch conductor. An auxiliary conductor is provided on the power supply side branch conductor or the power supply bus.

[0006]

Since the arc flows to the auxiliary conductor before proceeding to the electric equipment, damage to the electric equipment can be prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to a switchboard shown in FIGS.

FIG. 1 shows a circuit diagram in which a plurality of switchboards 1A to 1N are arranged in parallel, that is, in a row. The three-phase power supply conductors 2 are arranged in the plurality of switchboards, the power supply unit 3 is connected to the end portions of the three-phase power supply conductors 2, and the power supply side branch conductor 4A is connected to each power supply conductor 2. There is. The power supply side branch conductor 4A is connected to the input side of an electric device such as a circuit breaker 5 and a current transformer 5B. Load side branch conductor 4B connected to the output side of the circuit breaker 5
A current transformer 5B is connected to the. The auxiliary conductor 6 is attached to the power source conductor 2 and the branch conductor 4A on the power source side of the circuit breaker 5. The auxiliary conductor 6 may be provided only on the power supply conductor 2 or the branch conductor 4.

These power supply conductors 2, branch conductors 4A and 4B
The configuration of a single switchboard 1A in which electric devices such as the above are arranged will be described with reference to FIG.

The switchboard 1A has internal partition plates 10A, 10
B, 10C and 10D are attached to form a circuit breaker room 11, a bus room 12 and a cable room 13. The power source conductor 2 and the power source branch conductor 4A are attached to the insulator attached to the partition plate 10A on the ceiling side of the bus room 12. The power supply side branch conductor 4A is connected to the power supply side disconnecting section 15. The power supply side disconnecting section 15 and the load side disconnecting section 16 are attached to the partition plate 10A. Both disconnecting sections 15 and 16 are connected to the circuit breaker 5,
Moves in the circuit breaker room to electrically open and close both disconnecting sections 15 and 16.

The load side branch conductor 4B connected to the load side disconnecting portion 16 penetrates the current transformer 5B on the way and is connected to the cable 17. The cable 17 is drawn out of the switchboard from the cable chamber 13 and is connected to a load such as a motor. The cable chamber 13 is provided with a pressure release duct 13A. The pressure relief valve 13B that closes the opening of the pressure relief duct 13A is attached to the switchboard 1. Pressure relief valve 1 by pressure relief of arc A
Open 3B.

An auxiliary conductor 6 is attached to the power supply branch conductor 4A, the load side branch conductor 4B and the bent portions 19 thereof. The tips of the three-phase auxiliary conductors 6 are arranged correspondingly via a space as shown in FIGS. 4 to 6, and the shape of the auxiliary conductors 6 is inclined from the power source side toward the load side.

The arc-proof plate 20 is supported by a supporting member 21 supported between the arc-proof plate 20 and the partition plates 10B, 10C corresponding to the auxiliary conductor 6 as shown in FIG. The spring 22 is interposed. The arc resistant plate 20 operates the temperature sensitive element 23 by the arc heat when the arc is released, closes the operation switch 24, excites the trip coil 5A, and opens the circuit breaker 5. Alternatively, a switch that operates by pressing force when the arc is released may be used, or the short circuit current may be detected by the current transformer 5B to open the circuit breaker 5.

Next, when an arc A occurs due to a short-circuit accident in the power supply conductor 2, the arc A, as shown in FIGS. 3 to 6, is between phases, for example, a U-phase power supply branch conductor 4A and a V-phase power supply branch conductor. It moves in the direction of the auxiliary conductor 6, which is the load side when viewed from the point of flow that flows between 4A and 4A. This arc A does not move in the direction of the power source side disconnection part but moves to the auxiliary conductor 6 and becomes stagnant.

In order to hold the arc A in the auxiliary conductor 6, it is necessary to prevent the arc A from moving to the object to be protected. As shown in FIG. 4, the arc A generated in the parallel conductor between the U-phase power supply branch conductor 4A and the V-phase power supply branch conductor 4A from the power supply 3 is loaded from the generation point 1X by the electromagnetic force F1. It has the property of moving to the side at high speed.

Further, in the parallel conductor having the bent portion 19 shown in FIG. 5, the arc generated at the 1X point close to the power source side is at the 2X point on the load side and finally at the 3X point at the end according to the operation principle of FIG. It moves and damages electrical devices such as the power source side disconnecting section 15 and the circuit breaker 5.

However, when the auxiliary conductor 6 according to the present invention shown in FIG. 6 is attached, the arc A from the power source 6 moves from the 1X point close to the power source side to the 2X point by the electromagnetic force F2 and finally reaches the arc auxiliary conductor 6. Since it moves to the 4X point at the tip and stays there, it is possible to protect the electric equipment such as the power supply side disconnecting section 15 and the circuit breaker 5 without damage by the arc A.

The arc A reaches the arc resistant member 20 facing the extension line of the traveling direction, but the arc resistant material of the arc resistant plate 20 prevents the arc A from advancing, and therefore the arc resistant plate 20.
By this, it is possible to prevent the partition plate 10B from being melted and damaged.

Further, the internal pressure of the bus chamber 18 increased by the energy of the arc A is released from the pressure release valve 13B through the pressure release duct 13A from the opening near the arc point, and at the same time, the temperature sensitive element 23 is generated by the arc heat. Operates, the operation switch 24 is closed, the trip coil 5A is excited, and the circuit breaker 5 is opened.
The circuit breaker 5 stops flowing, and damage to the power supply side disconnecting section 15 and the like can be prevented.

The present invention can also be used in other electric equipment as an arc progress preventing device in which an arc flowing through a power supply conductor, a branch conductor, etc. is turned into an auxiliary conductor.

[0021]

As described above, according to the switchboard of the present invention,
It is possible not only to protect the electrical equipment by the arc by flowing an arc through the auxiliary conductor provided on the power supply side conductor of the electrical equipment to be protected, but also to break the breaker while the arc is stagnant. Since the short-circuit current is prevented from flowing in the electric equipment, it is possible to prevent the electric equipment from being damaged.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram when a plurality of switchboards shown as an embodiment of the present invention are arranged in parallel.

FIG. 2 is a side sectional view of the unitary switchboard of FIG.

FIG. 3 is an explanatory view of a main part of the single power distribution board of FIG. 1.

FIG. 4 is an explanatory diagram for explaining an arc moving state.

FIG. 5 is a perspective view for explaining an arc moving state.

FIG. 6 is a perspective view for explaining an arc moving state in the vicinity of the arc auxiliary conductor used in FIG.

[Explanation of symbols]

1A ... switchboard, 2 ... power conductor, 4A, 4B ... branch conductor,
5 ... Circuit breaker, 6 ... Auxiliary conductor.

Claims (8)

[Claims] 1. A switchboard in which a plurality of power supply conductors are arranged, wherein a plurality of branch conductors are connected to the power supply conductors, and an auxiliary conductor for flowing an arc is provided on the power supply side or power supply conductor of each branch conductor. . 2. The switchboard according to claim 1, wherein an electric device is connected to each of the branch conductors, and an auxiliary conductor for flowing an arc is provided to the power supply side branch conductor or the power supply conductor of the electric device. 3. The distribution board according to claim 1, wherein an arc resistant plate is installed at a portion of the distribution board irradiated with the arc from the auxiliary conductor. 4. The switchboard according to claim 1, wherein the shape of the auxiliary conductor protrudes in an inclined shape from the power source side toward the load side. 5. The switchboard according to claim 1, wherein at least two conductors are arranged correspondingly at the tip of the auxiliary conductor. 6. The switchboard according to claim 1, wherein the switchboard is provided with a pressure release valve for releasing the thermal pressure of the arc. 7. The trip coil is operated to shut off the circuit breaker when the switch operates due to any one of changes in the heat pressure, heat temperature, current, etc. of the arc on the switchboard. The switchboard according to any one of 7 above. 8. The switchboard according to claim 1, wherein the power supply conductor is provided with a plurality of auxiliary conductors.