JPS6051326B2 - Power distribution board grounding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention particularly relates to a grounding device for a closed type switchboard.

Normally, when performing maintenance and inspection on a load such as a rotating electric machine, it is natural to turn off the power to the load. is often left behind.

At this point, if maintenance and inspection of the rotating electric machine is carried out in its current state, depending on the environment and other factors, it may be extremely dangerous to the human body. For this reason, in the past, sufficient checks were made for such charging current and residual voltage even after the load was turned off. To do so, it was necessary to carry out ammeters and other equipment even in poor conditions and carry out dangerous investigation work. In addition, if there is a charging current or residual voltage, there are disadvantages such as having to take the trouble to connect another lead to ground, or install sufficient insulation equipment before maintenance and inspection of the rotating electrical machine, etc. It was hot. This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and the switch box housed in the switchboard main body is disconnected from the power supply side or load side only when the switch box is disconnected from the power supply side or load side. It is an object of the present invention to provide a grounding device for a power distribution board, which can be grounded on the side and can be released by connecting the switch box to the power supply side or the load side. An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 5, 1 is a switchboard main body, and 2 is a switch box housed inside the switchboard main body 1, which contains an internal disconnector, a conductor, and the like.

Reference numeral 3 has wheels so that the switch box 2 can be freely taken in and out of the switchboard main body 1.

4 is a power supply side connection terminal, and 5 is a load side connection terminal, both of which are attached to the outside of the switch box 2.

6 is the power terminal, 7 is the load terminal, both of which are connected to the power distribution board body 1.
By freely inserting and removing the switch box 2 from the switchboard main body 1, the switch box 2 can be freely connected to and disconnected from the power supply side connection terminal 4 and the load side connection terminal 5 provided on the switch box 2. There is.

A first grounding junction 8 is electrically connected to the load terminal 7, and a second grounding junction 9, which is a three-phase unit, is grounded to a grounding terminal 11 through a grounding wire 10.

12 is a support plate supporting the second grounding junction 9; 13 is a connecting rod; both ends of the rod are supported by supports 15 attached to the bulkhead 14 of the switchboard main body 1; a stopper 16 is attached to one end of the connecting rod; It is provided.

17 is a spring that always connects the second grounding junction 9 to the first grounding junction 9. It is now attached to the Junction 8 side.

An interlock pin 18 is provided with a spring 19 for moving the pin 18 downward, and these are supported by a support 20 attached to the other end of the connecting rod 13.

Reference numeral 21 denotes a guide attached to the bulkhead 14 of the switchboard main body 1. The interlock pin 18 moves on this guide 21, and the power supply side connection terminal 4 and load side connection terminal 5 provided on the switch box 2 are connected to each other. A groove 22 is provided so that the interlock pin 18 falls in when connected to the power supply terminal 6 and the load terminal 7, and a round hole 23 is provided concentrically with this groove 22.

24 is a load cable, one end of which is connected to the load terminal 7.

25 is a power line, and 26 is a common motherboard, which is connected to the power terminal 6 by the power line 25.

Reference numeral 27 denotes an electromagnetic operating device, which has an interlock ( (not shown) is provided.

A lever 28 is driven by an electromagnetic operating device 27, passes through a groove 22 and a round hole 23 provided in the guide 21, and is configured to move up and down.

Note that each of the members 12, 13, 15 to 23, and 28 constitutes an operating device 30 that operates the connection and separation of the first earthing junction 8 and the second earthing junction 9.

Next, the operation will be explained.

FIGS. 1 and 3 show normal operating conditions of rotating electric machines, etc., and the power supplied by the common bus 26 passes through the power line 25 and is further connected from the power terminal 6 to the power side connection terminal 4. The load cable 24 is connected through the switch box 2, the load side connection terminal 5 and the load terminal 7 to the load cable 24, and is connected to a rotating electric machine and the like for operation.

In this state, the connecting rod 13 is pushed rearward by the end face of the switch box 2, and the spring 17 is compressed.

In this case, the second grounding junction 9 attached to the connecting rod 13 is disconnected from the first grounding junction 8. Furthermore, the interlock pin 18 provided on the connecting rod 13 falls into a groove 22 provided in the guide 21 and is in a locked state. In this state, the electromagnetic actuator 27 cannot be operated, and the lever 28 does not move upward, so the lock is not released. Further, in this case, even if the switch box 2 is pulled out, the interlock pin 18 remains depressed in the groove 22, so that the lock cannot be released.

Figure 4 shows a state in which the switch box 2 is pulled out from the normal operating state and the load is disconnected from the power supply, and the load side connection terminal 5 of the switch box 2 is disconnected from the load terminal 7. However, the connecting rod 13 remains locked. The first grounding junction 8 is therefore disconnected from the second grounding junction 9. Fig. 2 and Fig. 5 show the state of a load such as a rotating electric machine during inspection, and the load side connection terminal 5 provided in the switch box 2 is disconnected from the load terminal 7, and the grounding device is not connected. It is in a grounded state.

When the switch box 2 is completely pulled out from the switchboard main body 1, the interlock (not shown) between the switch box 2 and the electromagnetic operating device 27 is released, and the electromagnetic operating device 27 can be opened from the front of the switchboard main body 1. It is ready for operation.

By operating this electromagnetic operating device 27, the interlock pin 18 is pushed up. Therefore, the lock is released from the groove 22 provided in the guide 21, and the force of the compressed spring 17 pushes the support plate 12 forward. Thereby, the second grounding junction 9 is connected to the first grounding junction 8, and the load cable 24 is grounded. Therefore, maintenance and inspection of the rotating electrical machine can be safely performed in this state. Next, to return to the normal operating state, push the switch box 2 into the switchboard main body 1, so that the end face of the switch box 2 pushes the other end of the connecting rod 13, so that the first grounding junction 8 and the second grounding junction 9 are automatically disconnected and grounded.

At the same time, the power supply side connection terminal 4 and the load side connection terminal 5 are connected to the power supply terminal 6 and the load terminal 7, respectively. In this case, the interlock pin 18 moves on the guide 21 and when it comes to the position of the miso 22, it falls into the miso 22 of the guide 21 due to the pressure of the spring 19, so the interlock pin 28 is pushed downward and the operation is stopped. An interlock is set to allow this. In the above embodiment, a grounding device for the load cable 24 was shown, but as shown in FIG. May be used.

As described above, according to the present invention, it is possible to ground the power supply side or the load side only at a position where the switch box is disconnected from the power supply side or the load side, and the switch box Alternatively, since the grounding device is configured to be automatically released by being connected to the load side, there is an effect that maintenance and inspection of the load or power source connected to the switchboard can be performed safely.

[Brief explanation of the drawing]

1 and 2 are cross-sectional side views showing a grounding device according to an embodiment of the present invention, and FIGS. 3, 4, and 5 are enlarged views of essential parts of the grounding device according to an embodiment of the present invention. , FIG. 6 is a cross-sectional side view showing another embodiment of the invention. In the figure, 1 is the switchboard main body, 2 is the switch box, 6 is the power terminal, 7 is the load terminal, 8, 29 is the first grounding junction, 9 is the second grounding junction, 11 is the grounding terminal, 30 There is a control device.

Claims (1)

[Claims] 1. A switchboard having a power terminal and a load terminal, a switch box housed in the switchboard and connected to and separated from the power terminal and the load terminal, and a first switch box connected to the power terminal or the load terminal of the switchboard. A grounding junction, a second grounding junction provided at a position opposite to the first grounding junction and connected to the grounding terminal, and the above-mentioned only when the switch box is disconnected from the power supply terminal or the load terminal. The first grounding junction and the second grounding junction can be connected to each other, and when the first grounding junction and the second grounding junction are connected to each other, the switch an operating device that disconnects the first grounding junction and the second grounding junction by connecting the box to the power supply terminal or the load terminal; the operating device disconnects the first grounding junction from the second grounding junction; a connecting rod supported at both ends by supports attached to the bulkhead of the switchboard body; a stopper that engages the connecting rod; a spring that biases toward the grounding junction, an interlock pin that engages with the connecting rod, and a spring that moves the interlock pin downward;
A support attached to the other end of the connecting rod, a guide attached to the bulkhead of the switchboard body, and a groove provided in the guide so that the interlock pin falls into it, and the groove is concentric with the groove. A round hole provided in the guide and an interlock that can be operated only when the power supply side connection terminal and load side connection terminal provided in the switch box are disconnected from the power supply terminal and the load terminal are provided. A grounding device for a power distribution board, comprising: an electromagnetic operating device; and a lever that is driven by the electromagnetic operating device and moves up and down through the groove and the round hole provided in the guide. .