阅读说明：本技术 用于真空断路器的触头监测模块装置以及具有该装置的真空断路器 (Contact monitoring module device for vacuum circuit breaker and vacuum circuit breaker with same ) 是由 催异在 于 2020-03-09 设计创作，主要内容包括：本发明涉及用于真空断路器的触头监测模块以及具有该模块的真空断路器。本发明的真空断路器具有推杆组件,所述推杆组件结合于真空灭弧室的可动电极而使所述可动电极升高或降低,以使可动触头进行触头闭合或触头断开,其中,所述触头监测模块包括：线性传感器,结合于所述推杆组件的下侧,以检测推杆沿其移动方向的位移；以及传感器支架,与所述推杆组件的下侧相邻设置并结合于所述线性传感器,以处理从所述线性传感器传递到的信号。(The present invention relates to a contact monitoring module for a vacuum circuit breaker and a vacuum circuit breaker having the same. The vacuum circuit breaker of the invention is provided with a push rod component, the push rod component is combined with a movable electrode of a vacuum arc-extinguishing chamber to enable the movable electrode to be lifted or lowered so as to enable a movable contact to carry out contact closing or contact opening, wherein, the contact monitoring module comprises: a linear sensor coupled to a lower side of the push rod assembly to detect a displacement of the push rod in a moving direction thereof; and a sensor bracket disposed adjacent to a lower side of the push rod assembly and coupled to the linear sensor to process a signal transmitted from the linear sensor.)

1. A contact monitoring module for a vacuum circuit breaker having a pushrod assembly that is coupled to a movable electrode of a vacuum interrupter to raise or lower the movable electrode so that the movable contact performs contact closing or contact opening, wherein the contact monitoring module comprises:

a linear sensor coupled to a lower side of the push rod assembly to detect a displacement of the push rod in a moving direction thereof; and

a sensor bracket disposed adjacent to a lower side of the push rod assembly and coupled to the linear sensor to process a signal transmitted from the linear sensor.

2. The contact monitoring module for a vacuum circuit breaker according to claim 1,

the linear sensor is coupled to a lower portion of a main lever that transmits a driving force generated from a mechanism assembly to the push rod assembly.

3. The contact monitoring module for a vacuum circuit breaker according to claim 2,

the main lever includes:

a pair of first and second links, one end of each of which is rotatably coupled to the output shaft of the mechanism unit and the other end of which extends to the opposite side of the mechanism unit and is fixed to an insulating case of the vacuum circuit breaker;

a plurality of connecting pins connecting the first link and the second link to each other; and

a connector coupled between the first link and the second link to couple the first link and the second link to the push rod.

4. The contact monitoring module for a vacuum circuit breaker according to claim 3,

the linear sensor and the sensor holder are disposed under the vacuum interrupter and the push rod assembly, and one end of the linear sensor and the sensor holder is disposed on a top surface side of a frame portion supporting the vacuum interrupter and the push rod assembly.

5. The contact monitoring module for a vacuum circuit breaker according to claim 4,

the linear sensor is coupled to a lower portion of the connector of the main lever.

6. A vacuum interrupter, comprising:

a main body provided with a mechanism assembly generating a driving force;

an insulating housing disposed at one side of the main body;

a vacuum interrupter module housed in the insulating housing; and

a contact monitoring module arranged at the lower part of the vacuum arc extinguish chamber module to detect the displacement of the push rod assembly along the moving direction,

the vacuum interrupter module includes: a vacuum interrupter having a fixed contact and a movable contact inside an insulating container; the push rod assembly receives the driving force from the mechanism assembly so as to enable the movable contact to be in contact with or separated from the fixed contact; and a main lever coupled to an output shaft of the mechanism assembly to transmit the driving force to the push rod assembly.

7. The vacuum interrupter of claim 6,

further comprising a carriage part movably supporting the main body and the vacuum interrupter module from a lower portion,

the mobile jib is in pairs configuration and combines each other, the one end of the push rod of push rod subassembly is located a pair of between the mobile jib, the mobile jib still including combine in the connector of the tip of push rod.

8. The vacuum interrupter of claim 7,

the contact monitoring module includes:

a linear sensor having one end coupled to the connector to detect a displacement of the push rod in a moving direction thereof; and

and a sensor holder having one end coupled to the frame portion and the other end coupled to the linear sensor to support the linear sensor, and outputting an output signal according to a detection result of the linear sensor.

Technical Field

The invention relates to a contact monitoring module device for a vacuum circuit breaker and the vacuum circuit breaker with the same, which can monitor the contact abrasion loss in a vacuum arc-extinguishing chamber.

Background

A vacuum circuit breaker is an electrical protector that protects load equipment and lines from a fault current when a fault such as disconnection or grounding of a circuit occurs, using the dielectric strength of a vacuum.

Vacuum circuit breakers are used for transmission control and protection of electrical power systems. The vacuum circuit breaker has the advantages of high breaking capacity, high reliability and high stability. In addition, since the vacuum circuit breaker can be installed in a small installation space, its application range is expanded from a medium voltage to a high voltage.

The vacuum circuit breaker includes a vacuum interrupter as a core component for cutting off a current, a power transmission device for transmitting power to the vacuum interrupter, and a push rod and the like which reciprocate up and down by the power transmission device to close or open a contact in the vacuum interrupter. An example of a vacuum interrupter as a core component of a vacuum circuit breaker is disclosed in korean patent registration No. 10-1860348 (registration date 2018.05.16).

The prior art vacuum interrupter disclosed in the above prior art document includes an insulating container, a fixed electrode, a movable electrode, and an arc shield. The fixed electrode and the movable electrode have a fixed contact and a movable contact, respectively. The movable contact is brought into contact with or separated from the fixed contact according to the up-and-down movement of the movable electrode.

When the current interrupting operation of the fixed contact and the movable contact is repeated, a problem of contact abrasion occurs. When the contacts wear to a certain extent, maintenance or replacement is required. If the contacts are not repaired or replaced in time, the short-time performance, the short-circuit performance, and the energization performance of the vacuum interrupter may be deteriorated. Therefore, a method of accurately detecting the wear state of the contact is required.

Disclosure of Invention

Problems to be solved by the invention

The invention aims to provide a contact monitoring module device for a vacuum circuit breaker and the vacuum circuit breaker with the same, wherein the contact monitoring module device can monitor the contact abrasion loss in a vacuum arc-extinguishing chamber.

Objects of the present invention are not limited to the above objects, and other objects and advantages of the present invention, which are not mentioned, may be understood by the following description and will be more clearly understood through embodiments of the present invention. It is apparent that the objects and advantages of the present invention can be achieved by the means shown in the claims and the combinations thereof.

Technical scheme for solving problems

The present invention provides a contact monitoring module for a vacuum circuit breaker having a push rod assembly which is combined with a movable electrode of a vacuum arc-extinguishing chamber to raise or lower the movable electrode so as to make the movable contact perform contact closing or contact opening, wherein the contact monitoring module comprises: a linear sensor coupled to a lower side of the push rod assembly to detect a displacement of the push rod in a moving direction thereof; and a sensor bracket disposed adjacent to a lower side of the push rod assembly and coupled to the linear sensor to process a signal transmitted from the linear sensor.

The linear sensor is coupled to a lower portion of a main lever that transmits a driving force generated from a mechanism assembly to the push rod assembly.

The main lever includes: a pair of first and second links, one end of each of which is rotatably coupled to the output shaft of the mechanism unit and the other end of which extends to the opposite side of the mechanism unit and is fixed to an insulating case of the vacuum circuit breaker; a plurality of connecting pins connecting the first link and the second link to each other; and a connector coupled between the first link and the second link to couple the first link and the second link to the push rod.

The linear sensor and the sensor holder are disposed under the vacuum interrupter and the push rod assembly, and one end of the linear sensor and the sensor holder is disposed on a top surface side of a frame portion supporting the vacuum interrupter and the push rod assembly.

The linear sensor is coupled to a lower portion of the connector of the main lever.

In addition, the present invention provides a vacuum circuit breaker comprising: a main body provided with a mechanism assembly generating a driving force; an insulating housing disposed at one side of the main body; a vacuum interrupter module housed in the insulating housing; and a contact monitoring module disposed at a lower portion of the vacuum interrupter module to detect displacement of the push rod assembly along a moving direction thereof, the vacuum interrupter module including: a vacuum interrupter having a fixed contact and a movable contact inside an insulating container; the push rod assembly receives the driving force from the mechanism assembly so as to enable the movable contact to be in contact with or separated from the fixed contact; and a main lever coupled to an output shaft of the mechanism assembly to transmit the driving force to the push rod assembly.

The vacuum interrupter module further comprises a frame part movably supporting the main body and the vacuum interrupter module from the lower part, the main rods are arranged in pairs and combined with each other, one end of a push rod of the push rod assembly is located between the main rods, and the main rods further comprise connectors combined with the end parts of the push rods.

The contact monitoring module includes: a linear sensor having one end coupled to the connector to detect a displacement of the push rod in a moving direction thereof; and a sensor holder having one end coupled to the frame portion and the other end coupled to the linear sensor to support the linear sensor, and outputting an output signal according to a detection result of the linear sensor.

Effects of the invention

The contact monitoring module for the vacuum circuit breaker can directly measure the abrasion loss of the contact, so that the abrasion loss of the contact can be monitored in real time.

In addition, the contact monitoring module for a vacuum circuit breaker of the present invention can determine the contact wear amount before the contact wear amount reaches above a limit value, and thus can determine an appropriate maintenance time point. Therefore, reliability and performance of the vacuum circuit breaker can be improved.

In addition to the above-described effects, specific effects of the present invention will be described below while describing specific details for implementing the present invention.

Drawings

Fig. 1 is a perspective view illustrating a vacuum circuit breaker to which a contact monitoring module according to an embodiment of the present invention is applied.

Fig. 2 is a perspective view partially showing the inside of the vacuum circuit breaker of fig. 1.

Fig. 3 is a sectional view partially showing the inside of the vacuum circuit breaker of fig. 1.

Fig. 4 is a side view showing a main part of the vacuum circuit breaker of fig. 1 in an enlarged manner.

Fig. 5 is a perspective view showing a set state of the contact monitoring module of fig. 2 from another angle.

Fig. 6 is a side view showing a main part of a contact open state of the vacuum circuit breaker of the present invention.

Fig. 7 is a side view showing a main part of a contact closed state of the vacuum circuit breaker of the present invention.

Fig. 8 is a side view showing a main part of a maximum abrasion state of a contact of the vacuum circuit breaker of the present invention.

Detailed Description

The above objects, features and advantages will be described in detail below with reference to the accompanying drawings, and thus, those skilled in the art to which the present invention pertains will be readily able to implement the technical ideas of the present invention. In describing the present invention, if it is determined that detailed description of known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar constituent elements.

Hereinafter, any configuration disposed on "upper (or lower)" of a component or "upper (or lower)" of a component means that any configuration is disposed in contact with a top surface (or bottom surface) of the component, and further, may mean that other configurations are interposed between the component and any configuration disposed above (or below) the component.

Further, when it is described that one constituent element is "connected", "coupled", or "coupled" to another constituent element, the constituent elements may be directly connected or coupled to each other, but it is understood that other constituent elements may be "interposed" between the respective constituent elements, or the respective constituent elements may be "connected", "coupled", or "coupled" by the other constituent elements.

Fig. 1 is a perspective view illustrating a vacuum circuit breaker to which a contact monitoring module according to an embodiment of the present invention is applied. Fig. 2 is a perspective view partially showing the inside of the vacuum circuit breaker of fig. 1. Fig. 3 is a sectional view partially showing the inside of the vacuum circuit breaker of fig. 1. Fig. 4 is a side view showing a main part of the vacuum circuit breaker of fig. 1 in an enlarged manner. Fig. 5 is a perspective view showing a set state of the contact monitoring module of fig. 2 from another angle. Fig. 6 is a side view showing a main part of a contact open state of the vacuum circuit breaker of the present invention. Fig. 7 is a side view showing a main part of a contact closed state of the vacuum circuit breaker of the present invention. Fig. 8 is a side view showing a main part of a maximum abrasion state of a contact of the vacuum circuit breaker of the present invention.

As shown in fig. 1 and 2, a vacuum circuit breaker 10 according to an embodiment of the present invention includes: a main body 100 provided with a mechanism assembly (not shown) generating a driving force; an insulating case 200 disposed at one side of the main body 100; a vacuum interrupter module 300 accommodated in the insulating case 200; and a frame part 400 movably supporting the main body 100 and the insulation case 200. The carriage part 400 is pushed into or withdrawn from a bracket (not shown), whereby the vacuum interrupter module 300 is brought into or out of contact with or separated from a bus terminal (not shown) and a load terminal (not shown). A contact monitoring module 500 for a vacuum circuit breaker is provided at a lower side of the vacuum interrupter module 300 to monitor wear of contacts.

A mechanism assembly generating a driving force is installed inside the main body 100. The driving force generated by the mechanism assembly is transmitted to the outside of the main body 100 through a plurality of links, shafts, and the like. The driving force is transmitted to the vacuum interrupter module 300 through the main rod 360 installed at the lower portion of the vacuum interrupter module 300. The main body 100 is mounted on the upper portion of the frame part 400, and the insulating case 200 is coupled to one side of the main body 100.

The insulating case 200 is mounted on the upper portion of the frame part 400 in a state where the vacuum interrupter module 300 is accommodated. The insulating case 200 is provided corresponding to the number of the vacuum interrupter modules 300. The terminals of the vacuum interrupter module 300 are exposed to the open side of the insulating housing 200.

As shown in fig. 2 and 3, the vacuum interrupter module 300 includes: a vacuum interrupter 310 having contacts therein; a push rod assembly 320 for closing or opening the contacts; a connecting rod 330 transmitting a driving force of the push rod assembly 320 to the vacuum interrupter 310; and an upper terminal assembly 340 and a lower terminal assembly 350 connected to the connection rod 330 and coupled to the upper and lower portions of the vacuum interrupter 310, respectively. The upper terminal assembly 340 and the lower terminal assembly 350 are portions of bus terminals (not shown) and load terminals (not shown) that are electrically connected to a bracket (not shown). The main lever 360 is coupled to a lower portion of the push rod assembly 320 to transmit a driving force to the push rod assembly 320.

Vacuum interrupter 310 includes: an insulating container 312 forming a receiving space; a fixed electrode 314 fixed to an upper portion of the inside of the insulating container 312; a fixed contact 314a provided at an end of the fixed electrode 314; a movable electrode 316 provided at the lower part of the inside of the insulating container 312 so as to be movable up and down; and a movable contact 316a provided at an end of the movable electrode 316. The inside of the insulating container 312 accommodates an arc shield 312a forming a vacuum, the arc shield 312a surrounding the fixed electrode 314 and the fixed contact 314a and the movable electrode 316 and the movable contact 316 a. The movable contact 316a is in contact with the fixed contact 314a (closed state) or separated from the fixed contact 314a (open state) by the movable electrode 316. Movable electrode 316 is raised and lowered by push rod assembly 320.

The push rod assembly 320 closes or opens the movable electrode 316. The push rod assembly 320 includes: a push rod 322 for transmitting the power of the main rod 360 to the movable electrode 316; a rod spring 324 elastically supporting the push rod 322; and a rod housing 326 that houses the push rod 322 and a portion of the rod spring 324. The push rod 322 is connected to the movable electrode 316 through a connecting rod 330.

The push rod 322 is raised or lowered by the main lever 360, thereby raising or lowering the connecting rod 330. The connecting rod 330 is raised or lowered by the push rod 322, simultaneously raising or lowering the movable electrode 316.

A state in which the movable electrode 316 is raised so that the movable contact 316a is in contact with the fixed contact 314a is referred to as a "contact-closed" state. In contrast, a state in which the movable electrode 316 is lowered so that the movable contact 316a is separated from the fixed contact 314a is referred to as a "contact-open" state. In the contact closed state, the fixed contact 314a and the movable contact 316a are in contact with each other to form an energized state, and in the contact open state, the fixed contact 314a and the movable contact 316a are separated from each other to form a current interrupted state. The vacuum circuit breaker 10 forms a contact open state to cut off the fault current when the fault current occurs. The push rod assembly 320 is driven by a main rod 360 provided at a lower portion of the push rod 322.

The main rod 360 is connected to a mechanism assembly to transfer power generated by the mechanism assembly to the push rod assembly 320. The main lever 360 has one end coupled to the output shaft 112 of the mechanism assembly and the other end extending to the opposite side of the mechanism assembly. A push rod 322 is connected to a predetermined position of the main lever 360. Since the push rod 322 needs to be raised and lowered by the main rod 360, the push rod 322 is preferably distanced from the output shaft 112 of the mechanism assembly in order to move the push rod 322 with a small force. In the present invention, the push rod 322 is illustrated as being connected to the right side 1/3 of the main lever 360, which is trisected, with reference to fig. 5.

The detailed structure of the main lever 360 is as follows.

As shown in fig. 3 to 5, the main lever 360 includes: a pair of first and second links 361 and 362; a plurality of connection pins 363 connecting the first link 361 and the second link 362 to each other; a connector 364 connecting the first link 361 and the second link 362 with the push rod 322; and a fastening member 365 coupled to the connector 364.

The first link 361 and the second link 362 have the same shape and are disposed opposite to each other. The first link 361 and the second link 362 have a flat bar (bar) shape having a predetermined length. Both end portions of the first link 361 and the second link 362 are formed in a semicircular shape, through holes are formed at both ends, respectively, and the connection pin 363 is inserted into the through holes.

The connection pin 363 is formed in a cylindrical shape and has a length sufficient to penetrate and insert the ends of the first link 361 and the second link 362. The connection pins 363 are provided in pairs and inserted into both ends of the first link 361 and the second link 362, respectively. The connection pin 363 rotatably supports the first link 361 and the second link 362. Although not shown in detail in the drawings, one of the pair of connection pins 363 may be connected to the mechanism assembly and the other may be coupled to the insulating housing 200. The connecting pin 363 connected to the mechanism assembly may also be directly connected to the output shaft 112, and in addition, the main rod 360 near the connecting pin 363 may also be connected to the output shaft 112.

Accordingly, one ends of the first link 361 and the second link 362 are raised or lowered by the output shaft 112 of the mechanism assembly 110. As one end of the first link 361 and the second link 362 is raised and lowered, the main lever 360 is displaced, and a contact monitoring module 500 described later detects it (which will be described later).

The connector 364 is disposed between the first link 361 and the second link 362, and is coupled with the first link 361 and the second link 362. The connector 364 is coupled with the push rod 322 by a fastening member 365. Therefore, the fastening member 365 needs to penetrate and insert the connector 364, and thus the connector 364 has a larger size than the fastening member 365.

Connector 364 is provided with contact monitoring module 500. Therefore, the connector 364 is formed in a size capable of ensuring an area sufficient for mounting the fastening member 365 and the contact monitoring module 500.

In addition, the connector 364 is required to raise or lower the push rod 322 in conjunction with the actions of the first link 361 and the second link 362. For this, the connector 364 needs to be rotatably coupled to the first link 361 and the second link 362. The connector 364 may have a cylindrical coupling pin 364a at both ends to be rotatably coupled to the first link 361 and the second link 362. The coupling pin 364a is inserted into the first link 361 and the second link 362 so that the connector 364 can be rotatably coupled to the first link 361 and the second link 362.

The above-described connection pin 363 and the coupling pin 364a may be further coupled at respective ends with a fixing member (not shown) such as an "E-ring" so as not to be disengaged in a state of being inserted into the first link 361 and the second link 362.

In order to measure the amount of movement of the push rod 322, it is necessary to detect the vertical displacement of the push rod 322. For this, as described above, the contact monitoring module 500 capable of detecting vertical displacement is provided on the lower side of the push rod assembly 320.

As shown in fig. 4 and 5, the contact monitoring module 500 is coupled to the connector 364 of the main lever 360 to detect the displacement of the push rod 322. The main rod 360 is coupled to the push rod 322, and the push rod 322 is driven in a length direction of the vacuum interrupter 310. The push rod 322 is connected to the movable electrode 316 through a connecting rod 330. Therefore, when the push rod 322 performs a raising or lowering motion, the movable electrode 316 is raised or lowered accordingly. As the contact closing is repeated, the movable electrode 316 gradually rises toward the fixed contact 314a due to an increase in the contact wear amount.

Therefore, a difference in displacement between the contact open state and the contact closed state of push rod 322 occurs in the longitudinal direction of vacuum interrupter 310 (the direction perpendicular to the plate surface of the frame portion). Accordingly, the contact monitoring module 500 may indirectly monitor the amount of contact wear of the vacuum interrupter 310 by detecting the displacement of the push rod 322.

The contact monitoring module 500 includes: a sensor holder 510 coupled to the frame portion 400; and a linear sensor 530 connecting the sensor holder 510 and the connector 364.

One end of the sensor bracket 510 is fixed to the top surface of the frame part 400, and the other end is connected to the linear sensor 530. The sensor holder 510 serves to mechanically support the linear sensor 530. Meanwhile, the sensor holder 510 performs a function of processing a signal of the linear sensor 530. To this end, the sensor holder 510 may include a circuit part (not shown) for processing a signal therein.

The sensor holder 510 may process the detection signal of the linear sensor 530 and output the signal to the outside. The output signal output from the sensor holder 510 varies according to the displacement value of the linear sensor 530. Therefore, using the signal output from the sensor holder 510, the movement displacement can be finally calculated. The signal output from the sensor holder 510 may be transmitted to an external data processing device, an intelligent terminal of an administrator, or the like, which is not shown.

The linear sensor 530 is a sensor having a cylindrical appearance, and is a sensor capable of detecting a displacement in the longitudinal direction. However, the linear sensor 530 is not limited to the above-described appearance, and may be replaced with another form of sensor as long as it can measure the displacement in the linear direction. The linear sensor 530 has one end connected to the sensor holder 510 and the other end connected to the connector 364 of the main lever 360. Since the connector 364 is connected to the lower end of the push rod 322, the linear sensor 530 detects the displacement of the push rod 322 by being provided to the connector 364. The linear sensor 530 detects displacement that varies when raised or lowered, and transmits a displacement value signal to the sensor holder 510.

The linear sensor 530 may be a sensor that is variable in length along the length of the outer appearance and is capable of detecting a varying displacement. The linear sensor 530 may be a sensor that detects the moving distance itself or detects a resistance value or a current value, etc., that changes according to the displacement. The linear sensor 530 may be applied regardless of its kind as long as it can detect a displacement difference occurring in the length direction.

Hereinafter, a method of monitoring the contact wear amount by the contact monitoring module 500 will be described.

In the present embodiment, with reference to fig. 6, the position of the right connecting pin 363 among the connecting pins 363 of the main lever 360 is defined as P1, the connecting portion of the push rod 322 and the main lever 360 is defined as P2, and the position of the left connecting pin 363 among the connecting pins 363 is defined as P3.

The push rod assembly 320 operates in the vertical direction, which is the up-down direction in fig. 5, and in the contact open state, the push rod assembly 320 is always maintained at the same position since the push rod 322 is not lifted. In the contact open state, a distance from the top surface of the frame portion 400 to P3 is defined as L1. The distance from the top surface of the frame portion 400 to P1 is defined as L2. Therefore, the stroke (vertical displacement) of the main lever 360 is L2-L1. In addition, the stroke of the vacuum interrupter 310 is the displacement difference (Δ S) between P1 and P2.

As shown in fig. 7, in the first closed state, the push rod assembly 320 exhibits a prescribed amount of vertical displacement. Since the P1 is fixed to the insulating housing 200, the position of the P1 in the state where the contact is first closed is the same as the position in the contact open state. At this time, since the main lever 360 is connected to the output shaft 112 of the mechanism assembly, P3 rises as the main lever 360 rises. Since the push rod 322 is raised by the main lever 360, the push rod 322 raises a predetermined distance between the fixed contact 314a and the movable contact 316 a. Thus, the position of P2 also rises.

When the contacts are first closed, the travel of the main lever 360 is the same as the contact open state. In addition, when the contacts are closed for the first time, Δ S is the same as the distance between the fixed contact 314a and the movable contact 316a (assuming that there is no amount of contact wear at the time of first closing).

However, as shown in fig. 8, when contact wear occurs as contact closure is repeated, the push rod assembly 320 is raised in the vertical direction corresponding to an increase in the amount of contact wear. As the position of P2 gradually rises as the contacts close, the stroke L2-L1 of the master lever 360 also gradually increases. In addition, since P2 gradually rises with respect to the position of P1 when the contacts are opened, Δ S also increases.

The contact monitoring module 500 is mounted to the bottom surface of the connector 364 to measure the displacement of P2. Therefore, as the push rod 322 is gradually raised as the contact wear amount increases as the contact closing is repeatedly performed, Δ S is gradually increased.

When there is no contact wear amount, the reference value of the Δ S value may be set by determining the distance between the fixed contact 314a and the movable contact 316 a. When the Δ S value is greater than the reference value, the difference thereof may be determined as the contact wear amount.

Therefore, when the contact wear amount is equal to or more than a predetermined set value, the administrator can be notified of the contact wear amount. The subject of all of the above described decision and control actions may be an external data processing device or administrator connected to the sensor holder 510.

As described above, the contact monitoring module for a vacuum circuit breaker of the present invention can directly measure the wear amount of the contact, and thus can monitor the wear amount of the contact in real time.

In addition, the contact monitoring module for a vacuum circuit breaker of the present invention can determine the contact wear amount before the contact wear amount reaches above a limit value, and thus can determine an appropriate maintenance time point. Therefore, reliability and performance of the vacuum circuit breaker can be improved.

It will be apparent to those skilled in the art to which the present invention pertains that various substitutions, modifications and changes may be made without departing from the technical spirit of the present invention, and therefore the present invention described above is not limited by the above-described embodiments and the accompanying drawings.