JPS607441Y2 - Lightning arrester with safety protection display - Google Patents

Description

[Detailed description of the invention] The present invention uses an oxide voltage nonlinear resistance element that absorbs abnormal voltages such as lightning surges and switching surges, and prevents accidents from spreading when the characteristics of the oxide voltage nonlinear resistance element deteriorate. The present invention relates to a lightning arrester with a safety protection display that minimizes damage, increases reliability, and facilitates maintenance and inspection.

First, to explain the oxide voltage nonlinear resistance element,
Oxide voltage nonlinear resistance elements function to bypass abnormal voltages when abnormal voltages occur, but if this characteristic deteriorates during the use of the element, the resistance will decrease due to the fact that it generally has a negative temperature coefficient. The phenomenon occurs in that the value decreases, the leakage current of the element increases, and as a result, heat generation, smoke generation, and ignition occur at an accelerating rate.

Similarly, if an extremely large abnormal voltage exceeding the rating of the element is applied, the element may be destroyed.

The destruction mode at this time is to vary the resistance value over a fairly wide range.

At times, there is a wide range of iodines ranging from states that history the above phenomena to conductive states.

From the above, when a conventional lightning arrester is destroyed,
There was a danger that heat generation, smoke, and ignition could cause peripheral circuit components to catch fire, increasing the number of failure points.

The present invention aims to provide a lightning arrester with a safety protection display that prevents oxide voltage nonlinear resistance elements from emitting smoke or ignition, makes it possible to identify deteriorated elements from their appearance, and greatly improves reliability. This is the purpose.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lightning arrester with a safety protection display according to the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of the external appearance of this embodiment, FIG. 2 is a side view of the same, FIG. 3 is a front view of the same case with a part cut away, and FIG. 4 is a side view of the same.

In Figures 1 to 4, 1 is an insulating case, 2 is a temperature fuse that melts when it reaches a certain temperature, 3 is an electrode piece, 4 is a movable electrode/deterioration indicator piece made of a leaf spring, and 5 is a deterioration display piece. 6 is a current fuse, and 7 is an oxide voltage nonlinear resistance element.

In the above configuration, the current fuse 6 and the temperature fuse 2 are connected in series to the oxide voltage nonlinear resistance element 7,
Each of the fuses 2 and 6 is led out to the electrode piece 3 via a movable electrode and deterioration indicator piece 4 of a plate spring.

When the oxide voltage non-linear resistance element 7 used here as a lightning arrester generates heat due to characteristic deterioration, it is attached to the electrode part located closest to the element 7, and the plate of the movable electrode/deterioration indicator piece 4 As a result, the temperature fuse 2, to which a tension force is constantly applied by the spring, melts, and as a result, the movable electrode/deterioration indicator piece 4 changes its position to 4', and the circuit is cut off.

Furthermore, if an abnormal voltage that significantly exceeds the specifications of the oxide voltage nonlinear resistance element 7 is applied, a breakdown mode may occur to the extent that it becomes conductive.

In this state, no heat is generated in the oxide voltage nonlinear resistance element 7, and an extremely large current flows through the circuit used.

In this case, the temperature fuse 6 is blown and the circuit is cut off.

No matter which of the above operations is performed, since the plate spring-shaped movable electrode/deterioration indicator piece 4 is in a position where the operation can be confirmed through the hole 5 made in the case 1, the oxide voltage nonlinear resistance element 7
The structure is such that deterioration can be easily detected from the outside.

As is clear from the above explanation, the lightning arrester with safety protection display according to the present invention does not cause any accidents due to heat generation even if the oxide voltage nonlinear resistance element used therein deteriorates or is discarded. In addition, the structure is such that the current fuse is cut off by the current generated when a short circuit occurs, which has the advantage of preventing accidents from spreading and facilitating maintenance and inspection.

In addition, when the oxide voltage nonlinear resistance element deteriorates, the leakage current generates heat and shuts off, so the resistance element does not break into waves and follow-on current flows in, and the effect of follow-on current on the electrical system ( For example, the operation of overcurrent relays, earth leakage breakers, etc.) can be avoided as much as possible.

In addition, since the temperature fuse is located near the oxide voltage non-linear resistance element, if the voltage non-linear resistance element generates heat due to characteristic deterioration, that heat will be efficiently transferred to the temperature fuse. The disconnection operation is performed reliably.

Since the oxide voltage nonlinear resistance element and the current fuse are electrically connected by the temperature fuse, the connection between them is better than when the current fuse and temperature fuse are configured separately. This invention has great effects on practicality and safety, as the number of parts such as lead wires is reduced, the number of assembly steps is reduced, and as a result, the reliability of the product can be improved. It is something.

[Brief explanation of drawings]

Fig. 1 is an external front view of one embodiment of the lightning arrester with safety protection display according to the present invention, Fig. 2 is a side view of the same, Fig. 3 is a front view of the same case with a part cut away, and Fig. 4 is It is the same side view. 1...Case, 2...Temperature fuse,
4...Movable electrode and deterioration indicator piece, 6...
Current fuse, 7...Oxide voltage nonlinear resistance element.

Claims (1)

[Scope of utility model registration request] An oxide voltage non-linear resistance element and a current fuse are connected in series via a temperature fuse, the temperature fuse is located near the voltage non-linear resistance element, and they are housed in a case, each of the above A tensile force is constantly applied to the fuse by an elastic movable electrode and deterioration indicator.
When the temperature fuse or the current fuse is blown, the circuit is completely cut off by the action of the movable electrode and deterioration indicator, and the oxide voltage non-linear resistance is caused by the action of the movable electrode and deterioration indicator. A lightning arrester with a safety protection display, characterized in that deterioration of the element is clearly indicated.