JPH02193528A - Lightning arrestor for high-sensitivity, large-capacity and low-pressure circuit - Google Patents

Abstract

PURPOSE:To prevent the excess of a resistible amount against Joule by a method wherein a non-induction type resistor, having the value of resistance higher than a value obtained by dividing a difference between a discharging starting voltage and a limit voltage by a current and the resistible amount against Joule, which is higher than a value obtained by an operation considering a current corresponding to the resistible amount against surge, is inserted into the title circuit. CONSTITUTION:A vessel 1 is provided with a standing rim 2 at the outer periphery thereof, partitioning plates 3, 4, reinforcing parts 5, 6 and a recessed chambers 7 therein while contacting and pinching pieces 8, 9 are established in the recessed chambers 7. The standing rim 2 is provided with notch grooves 10 while the vessel 1 is provided with mounting holes 11 and a recessed groove 12. A lid 20 is provided with standing pawls 23, 24 while grooves 25 are provided to form spark gaps 28 by opposing the extended parts 26, 27 of the pawls 23, 24 against gaps. Characteristic elements 31, 32 are connected in parallel to the spark gaps 28 while non-inductance resistors 51, 52 are inserted in series to the middle part of a lead wire. A thermolabel 46 detects heat generation and generates color change whereby the state in the title arrestor may be recognized visually.

Description

[Detailed Description of the Invention] [Field of Industrial Application] In recent years, automation has become widespread in a wide range of areas, including factories and research institutes, offices, hospitals, golf courses and other sports facilities, and agricultural facilities. Many electronics mechanisms are used.

Those devices are truly vulnerable to lightning surge voltages.

Surge voltage is not only on the @ side, but also on the above-mentioned facilities where there is a signal circuit, there are heavy lightning areas and areas with strong electricity such as winter lightning, but in addition, the location conditions are mountainous areas and sand dune areas across riverbeds. If so, the ground resistivity at that location will be high, and the lightning current will not be immediately dissipated into the ground, but will travel over a wide area along nearby power lines, causing greater damage.

On the other hand, as automation progresses, the number of unmanned facilities will also increase. Due to unmanned systems, even if a lightning arrester breaks down, maintenance personnel will have to be dispatched from afar. Therefore, the demand for lightning arresters will continue to increase in the future, but they can withstand considerably more energy than conventional ones, and not only protect equipment from the repeated penetration of powerful lightning surges, but also prevent the lightning arrester itself from burning out. There is a strong demand for a system that takes this into account because it is easy to maintain and reduces management costs.

The high-sensitivity, large-capacity, low-voltage circuit lightning arrester of the present invention was proposed for this purpose, and has a wide range of applications in various fields.

[Conventional technology]

Conventionally, lightning arresters are broadly classified into the following 7 types.

1, spark gap 2, gas discharge tube type lightning arrester 3, semiconductor type lightning arrester 4, series circuit of (2) and (3) 5, parallel circuit of (2) and (3) 6, (1) and (3) ) series circuit? , parallel (c) path of (1) and (3) However, (1) is a lightning surge caused by multiple lightning strikes or continuous discharge,
Although it is easy to obtain a device that can withstand large amounts of energy such as from nearby lightning strikes, it has the disadvantage of slow response time at the start of operation, and (2) has a small capacitance and a relatively large current capacity. However, when used in a power supply circuit, it has the disadvantage that follow-on current due to the power supply voltage cannot be interrupted immediately after discharge. In principle, (3) is sensitive to lightning surges, but if a voltage exceeding the limit voltage acts frequently, the operating start voltage of the element will decrease, and the circuit will suddenly become short-circuited even with just the voltage applied to the circuit. If the electric oil is not turned off, a sudden fire may occur. Those with high surge resistance have a large capacitance and a large volume, making them unsuitable for indoor use. In (4), it is used in the power supply circuit.
There is no need to worry about follow-on current, the capacitance is small (does not interfere with the operation of protective equipment), and the steepness and voltage width are relatively small.
On the other hand, if a lightning surge occurs due to continuous discharge with a long energization time, or if a lightning surge occurs due to multiple lightning strikes, the problem remains that the energy and weight resistance is insufficient, resulting in burnout.

In (5), if a suitable combination can be obtained, it is possible to obtain one that is sensitive and has a relatively large amount of energy.
Power supply circuits still have the disadvantage of not being able to block follow-on current, and there is no guarantee that they will be able to sufficiently withstand surges from multiple lightning strikes, even if they are used in weak circuits (6). Are there any concerns about follow-on current, as the spark gap will interfere with the sensitive response of the semiconductor device?
It is hardly used now.

In the case of (7), since elements with different properties are connected in parallel, some of the disadvantages of 6 can be compensated for, so if the combination is good, a considerable effect can be expected. However, simply connecting two elements in parallel makes it difficult to coordinate the operations of the two elements, for example, due to the complexity of the semiconductor lightning arrester.

[Problem to be solved]

It is possible to commutate lightning surges from a semiconductor type lightning arrester (hereinafter referred to as a surge absorber) to the spark gap, but it is necessary to coordinate the operation starting voltage and maximum limiting voltage of both the surge absorber and the spark gap. Of course, this is necessary, but care must be taken to ensure that the joule resistance of the surge absorber is not exceeded until the spark gap operates. virtue? This surge absorber is a nonlinear resistor that changes depending on the magnitude of the current, so it is extremely difficult to coordinate its operation, and the surge absorber may be thermally destroyed before the spark gap operates. There were many.

It was even more difficult in the case of a gas discharge tube type 111 element (hereinafter simply referred to as a gas discharge tube) and a spark gap.

[Means to solve the problem]

The upper limit of the limit voltage of the surge absorber overlaps the discharge starting voltage of the spark electrode.A high-performance low pressure avoider is made by connecting spark electrodes in parallel and integrally, and the discharge starting voltage of the spark gap is reduced by the surge absorber. A non-inductive resistor with a resistance value that is approximately equal to or greater than the value divided by the current (1) corresponding to the surge withstand capacity of the surge absorber, and a Joule withstand capacity greater than that calculated by the current (1) that corresponds to the surge withstand capacity of the surge absorber. Insert in series with the surge absorber.

In addition, in the case of a combination of a gas discharge tube and a spark gap, a non-inductive resistor (I
t) in series.

However, in any of the above cases, the use of a non-inductive resistor is an important factor because it does not interfere with the characteristics of the surge absorber (or gas discharge tube).

[For production]

In the case of a surge absorber, below the response voltage it behaves like a good insulator, but above it the current is 1 part of the voltage.
Since it can be considered as a non-linear cedar resistor that increases by the 5th to 30th power, the response speed to the impact voltage is fast and there is almost no time delay. Connect a suitable surge absorber in parallel to the spark electrode,
By overlapping the limiting voltage of the surge absorber and the discharge starting voltage of the spark gap, it is theoretically possible to avoid overloading due to the unavoidable roll-call delay of the spark electrode.

However, the maximum limit voltage of a surge absorber is determined by the damage and bendability of the elements, and the internal resistance value is unstable.Unlike theory, it is actually impossible to make each element work together without destroying it in any case. This was a difficult problem.

However, these drawbacks can be compensated for by connecting the surge absorber and a non-inductive resistor having appropriate characteristics as described above in series.

When a steep and large lightning surge current acts, in Figure 1, the absorber (A) first operates. At this time, resistor R shares part of the voltage, and the burden on the absorber can be reduced by that much. Next, surge absorber (A)
and the resistor (R) are connected in series, so the terminal voltage of the resistor (R) will surely rise as calculated, and if the voltage rises beyond the discharge starting voltage of the spark electrode, the spark electrode will finally discharge. do.

Thus, the spark gear is removed from the surge absorber. It is certain that the lightning surge will be diverted.

Since the spark electrode can be designed into a container with a large current withstand capacity, even in the case of a fairly large surge current or multiple lightning strikes, the surge absorber has a joule withstand capacity that is only for the short operating time until the spark electrode ignites. As long as it is, burnout due to overload can be completely prevented.

Similarly, in the case of a combination of a gas discharge tube and a spark gap, if the resistor described above is connected in series with the gas discharge tube, lightning surge can be commutated to the spark gap without burning out the gas discharge tube. .

Example] Here, a flat partition plate 3.4 is provided in the high-sensitivity, large-capacity, low-voltage lightning arrester according to the present invention, and a reinforcing portion 5.6 is provided to form a concave chamber 7.
are installed in four locations.

The container 1 is made of heat-resistant and insulating porcelain. Two pairs of contact clamping pieces 8.9 are provided upright in the recessed chamber 7. Contact clamping piece 8
．． 9 are connected by a bar 81 in a groove provided on the back side of the container 41.

This contact clamping piece 8.8 is for grounding.

There are cutouts for wiring above and below the vertical edge 2.
It10 is provided, and a mounting hole 11 to the wall surface is provided. A groove 12 is provided in the lower part of the inner surface of the container 1, and a metal pivot piece 13 is provided within the groove 12.

The metal pivot piece 13 has bearing arms 4 which are bent left and right erected, and a bearing hole 15 is formed in the metal pivot piece 13.

The lid 20 that closes the container I is made of porcelain and has two flat edges around the periphery to form a concave surface 22, and the contact clamping piece 8.9
Two pairs of adult claws (=electrodes) 23 and 24 are provided erected facing each other.

A groove 25 is provided between the pawls 23, 24 to form a gap, and a spark gap 28 is formed in which the extensions 26, 27 of the plate pawls 23, 24 are opposed. Distraction section 261.27
is provided with a hanging piece 29.30 which is bent at a right angle and inserted into the FR25 at the tip. In this spark gap 28,
Characteristic elements 31, 32 such as surge absorbers are connected in parallel. The characteristic elements 31 and 32 each have a claw 23
．． 24 to the center of the back side of the lid 20 with a lead wire 35. The space required for the characteristic elements 31 and 32 can be saved by stacking two of them with an insulator 36 such as mica in between. The stacked characteristic elements 31 and 32 are fixed at both ends with a band 38 which is fastened with a nut 37. Characteristic element 31.3
A non-inductive resistor is connected in series to the middle portion of the second lead wire.

A metal connecting piece 41 is fixed in a groove 40 above the lid 20.

Metal connecting piece 4! Protrusions 42 connected to the bearing hole 15 of the metal pivot piece I3 are provided on both sides of the tip, and a notch 43 is provided under one of the protrusions 42 so that the metal pivot piece I3 can be easily attached to and removed from the bearing hole 15. In addition, a spring 44 is provided on the protrusion 42.

and M2O are connected so as to be openable and closable.

It can be easily removed by pushing it to the right against the spring 44 and pulling out the protrusion 42.

In the center of the lid 20, there is a through hole 45 or 1 formed with a wide mouth. It is on one level.

A completely irreversible thermolabel 4 is inserted through the through hole 45 of the lid 20.
I can see 6. The thermolabel 46 has characteristic elements 31.32
, and at least one has a through hole 46.
It is attached to the inner characteristic element 31 so that it can be seen from the outside.

The other one is attached to the characteristic element 32 so that it is visible when the lid is opened.

The thermo label 46 senses the heat generated inside the lightning arrester and causes a color change from white to red, etc., so that the internal situation can be visually seen from the outside.

A highly sensitive, large-capacity, low-voltage lightning arrester with such a configuration has a circuit as shown in FIG. 5, in which the power supply side and the ground side E are separated and connected by a switch S by opening and closing the lid.

In addition, the main resistor is a non-inductive type resistor with a large current capacity.
Pi filer winding as shown in figure (a) or similarly (b)
As shown in Figure 2, it can be obtained by winding two resistance wires on an insulating plate, one to the right and the other to the left.

〔effect〕

The high-sensitivity spark gap type lightning arrester for low voltage of the present invention carefully adjusts the gap between the spark electrodes and directly connects the surge absorber (A) (or gas discharge tube (B)) and non-inductive resistor (R). For example, for the reasons detailed above, it is possible to construct a surge arrester that operates more sensitively and skillfully and has a larger current capacity than using individual lightning arrester elements separately or in known combinations. The lightning arrester will not burn out even if a fairly large surge voltage enters, so even multiple lightning strikes will not burn out the protection.

In most cases, when multiple 1M strikes are carried out, the arrester is destroyed by the first strike, and the protection is destroyed by the second strike.

The number of lightning arresters continues to increase, but the conventional thinking was that it was unavoidable that the lightning arrester would break if the protection was protected, but this requires a lot of maintenance and is not economical. . Therefore, the present invention greatly contributes to labor saving.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of a high-sensitivity, large-capacity lightning arrester according to the present invention. 2 to 6 also show one embodiment of the lightning arrester of the present invention. FIG. 2 is a front view of the surge arrester in the open state, FIG. 3 is a partial central sectional view of the surge arrester in the closed state, and FIG. , FIG. 5 is a perspective view showing a partial cross-section of a spark gap, and FIG. 6 is an example of a circuit diagram of the lightning arrester of the present invention. FIGS. 7(a) and 7(b) are perspective views of main parts such as a non-inductive resistor. l・・・・・・・・・・・・Container 20・・・・・・・・・・・・Lid 28・・・・・・・・・Spark gap 31.32
・・・・・・Characteristic elements (surge absorber) ・Non-inductive resistor Figure 1 Figure (a-) Neartonbury Temple

Claims (2)

[Claims] (1) In a type of lightning arrester in which a semiconductor lightning arrester (A) and a spark gap (G) are connected in parallel and integrated, a non-inductive resistor (R
) are inserted in series to ensure operational coordination between the semiconductor type lightning arrester (A) and the spark gap (G). (2) Gas discharge tube type lightning arrester (B) and spark gap (G)
In this type of lightning arrester, a non-inductive resistor (R) is connected to a part of the connecting wire of the gas discharge tube type lightning arrester (B), and the gas discharge tube type lightning arrester (B) is connected in parallel. ) and the spark gap (G) are highly sensitive, large capacity, low circuit lightning arresters that ensure operational coordination.