JP2001190022A - Lightning protection device provided with automatic reset function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightning protection device provided with an automatic reset function which can turn off a load opening/closing unit at the time of lightning, can be quickly and automatically set and does not automatically set the load opening/closing unit during the lightning. SOLUTION: A control unit 6 for controlling opening and closing conditions of a load opening and closing unit such as a load cut-off unit 3 or the like is provided with a function to open the load opening/closing unit and start a timer when the current detected with a lightning sensor 10 exceeds the predetermined value, a function to automatically set again the load opening/closing unit after the constant time preset to the timer has passed, and a function to reset the count of the timer when the lightning sensor 10 has detected, during operation of the timer, the current exceeding the predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning protection device having an automatic return function.

[0002]

2. Description of the Related Art In many cases, mobile phones and other communication bases are installed in remote places where workers do not reside. For this reason, when the shut-off device (distribution breaker) installed in the power supply circuit to the communication equipment as a load is operated and turned off, the worker arrives at the site and turns on the power again. It takes a considerable amount of time, during which time communication may not be possible. Therefore, a lightning protection device is conventionally used in which an automatic input device is incorporated in a load interrupting unit, and the automatic input device is operated by remote control to automatically return the load interrupting unit.

In order to protect the equipment from lightning surge currents caused by induced lightning or the like, a lightning sensor is connected to the control unit of the lightning protection device, and when the lightning sensor detects a current exceeding a predetermined value, the load interrupting unit is turned off. It has also been done. In this case, if the thundercloud leaves, it is necessary to turn on the power again. Therefore, after a certain time set in the timer has elapsed, the automatic turning-on device is operated to automatically return the load shedding unit.

[0004] However, since the moving state of the thundercloud varies, sometimes the thundercloud does not leave even after the elapse of a predetermined time set in the timer, and the load shedding unit may be automatically restored at the peak of lightning. In this case, there is a possibility that the lightning surge current will enter after the automatic recovery and the electronic device will be destroyed. Further, if the setting time of the timer is set to be very long in order to avoid such a problem, there is another problem that the load shedding unit remains off for a long time even after the thundercloud has left.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. The load switching unit can be turned off in the event of a lightning strike, and can be immediately turned on again after the thundercloud has left. Further, the present invention has been made to provide a lightning protection device having an automatic return function that does not cause the load switching unit to automatically return during a lightning strike.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a lightning protection device including a load switching unit, a control unit for controlling opening and closing of the load switching unit, and a lightning sensor. The control unit opens the load switching unit when the detection current of the lightning sensor exceeds a predetermined value, activates a timer, and automatically resets the load switching unit after a fixed time set in the timer, It has a function of resetting the count of the timer when the lightning sensor detects a current exceeding a predetermined value during the operation of the timer.

In the lightning protection device having an automatic return function according to the present invention, the control unit resets the count of the timer when the lightning sensor detects a current exceeding a predetermined value during the operation of the timer. Counting starts. Therefore, the reset is repeated while the lightning sensor is detecting a current exceeding a predetermined value, so that the load switching unit does not automatically return during the lightning strike.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention, in which 1 is a circuit connected to a load 2 such as a communication device, and 3 is a load cutoff as a load switching unit provided on the circuit 1. Department. The load interrupting section 3 is composed of a contact 4 and a trip device 5 as in the conventional case. The load interrupting unit 3 is controlled by the control unit 6, and when an overcurrent flows through the circuit 1, the load interrupting unit 3 is operated to interrupt the circuit 1 as in the conventional case. Reference numeral 7 denotes an automatic closing device for the contact 4, which is capable of automatically returning the load breaking unit 3 when receiving a closing signal from the control unit 6 and automatically closing the contact 4.

Reference numeral 8 denotes a lightning arrester connected to the circuit 1. When an excessive surge voltage is generated in the circuit 1 due to lightning, the gap is discharged, and the surge is released to the ground through the ground wire 9 connected to the secondary side. have. Reference numeral 10 denotes a lightning sensor, such as a CT, provided on the ground wire 9. When a gap between the lightning arresters 8 discharges and a current flows through the ground wire 9, the current value is detected and input to the control unit 6. .

The control unit 6 of the present invention has the following three functions. First, when the current detected by the lightning sensor 10 exceeds a predetermined value, the control unit 6
Is operated, the contact 4 is turned off, the circuit 1 is cut off, and the timer of the control unit 6 is started. As a result, when lightning strikes in the vicinity, load 2 is disconnected from circuit 1 and load 2
Can be protected from lightning surges.

Second, after a predetermined time set in the timer elapses, the control section 6 sends a signal to the automatic input device 7 to operate the same, and the load shedding section 3 is automatically returned. This is shown in FIG. Since the timer setting time can be set freely, if the time required for the thundercloud to go away after the first lightning strike is set, it is necessary to turn on the contact 4 again even if the worker does not go to the site Can be. Therefore, the function of the load 2 can be quickly restored.

Third, when the lightning sensor 10 detects a current exceeding a predetermined value again during the operation of the timer, the control unit 6
The count of the timer is reset to 0, from which point the timer starts counting again. Therefore, as shown in FIG. 3, the timer is reset each time the lightning sensor 10 detects a current exceeding a predetermined value during the operation of the timer, and when the set time has elapsed since the last reset, the control unit 6 automatically operates. The input device 7 is operated, and the load shedding unit 3 is automatically returned.

Since the lightning protection device having the automatic return function according to the present invention is as described above, the load interrupting unit 3 operates automatically while the lightning sensor 10 intermittently detects a current exceeding a predetermined value. It does not return, and there is no risk that the load shedding unit 3 will automatically return during a lightning strike as in the related art. Also, by properly setting the timer setting time,
After the thundercloud has left, the load shedding unit 3 can be automatically returned immediately to restore the function of the load 2.

The lightning surge before the operation of the load interrupting unit 3 can be interrupted by an initial lightning surge by adjusting a predetermined value set in the control unit 6 in advance. Yes, there is no possibility that the load equipment will be affected.
In the above embodiment, the load switching unit 3 is used as the load switching unit.
However, a load switch without a tripping device may be used. In this case, to disconnect the power supply from the load,
When the current detected by the lightning sensor 10 exceeds a predetermined value, a signal is output from the control unit, and the automatic switching device is operated to open the load switch.

In the second embodiment shown in FIG. 4, an electromagnetic switch 13 is used as a load switch.
The control unit 16 having received the signal from the lightning sensor 10 directly controls the opening and closing of the electromagnetic switch 13. In this case, the control unit 16 has the following functions. First, the control unit 16 opens the electromagnetic switch 13 when the current detected by the lightning sensor 10 exceeds a predetermined value, disconnects power from the load, and starts a timer of the control unit 16. Second, the control unit 16 closes the electromagnetic switch 13 after a lapse of a predetermined time set in the timer, and turns on the power to the load. This situation is the same as that shown in FIG. 2 described in the first embodiment. Third, when the lightning sensor 10 detects a current exceeding a predetermined value again during the operation of the timer, the control unit 16 resets the count of the timer to 0, and from that time the timer starts counting again. This is the first
This is the same as that shown in FIG. 3 described in the embodiment. As described above, since the control unit 16 directly controls the opening and closing of the electromagnetic switch 13, an automatic insertion device becomes unnecessary, which is advantageous in terms of cost.

Further, the apparatus of the present invention can be combined with a remote control operation from a remote place, and can be switched from automatic operation to remote control operation so that an operator can turn on / off the load shedding unit 3.

[0017]

As described above, the lightning protection device provided with an automatic return function according to the present invention can turn off the power during a lightning strike to protect the load from lightning surge, and after the thunder cloud has left. Has the advantages that it can be quickly turned on again and that there is no possibility that the power supply will be automatically restored during a lightning strike.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the device of the present invention.

FIG. 3 is a time chart showing the operation of the device of the present invention.

FIG. 4 is a block diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit 2 Load 3 Load switching part 4 Contact 5 Tripping device 6 Control part 7 Automatic closing device 8 Lightning arrester 9 Ground wire 10 Lightning sensor 13 Electromagnetic switch 16 Control part

Claims (1)

[Claims] 1. A lightning protection device comprising a load switching unit, a control unit for controlling the opening and closing of the load switching unit, and a lightning sensor, wherein the control unit is configured to load when a lightning sensor exceeds a predetermined value. Opening the switching unit, starting the timer, and automatically resetting the load switching unit after a certain period of time set by the timer, and counting the timer when the lightning sensor detects a current exceeding a predetermined value while the timer is operating. A lightning protection device having a reset function.