JPH03295127A - Overcurrent trip device of circuit-breaker - Google Patents

Abstract

PURPOSE:To use parts or assembly lines in common to achieve low cost by forming an electronic circuit-breaker by using a mechanical circuit-breaker and a circuit-breaker main body in common. CONSTITUTION:An electronic circuit-breaker can be manufactured by using a mechanical circuit-breaker and a circuit-breaker main body 13 in common, and by mounting a trip coil unit 12 in the main body 13 instead of a mechanical overcurrent tripping device, and further, by fitting a mold case 15 to a load side, so as to connect a conductor 10 to a terminal part 14. Parts and assembly lines can thus be used in common, and various electronic overcurrent tripping device of different functions can be freely chosen according to the purpose of a client, without adding alternation to a case 1 or cover 2 in the side of the main body 13.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an electronic overcurrent tripping device used in a circuit breaker such as a molded case circuit breaker.

[Prior Art I] An overcurrent trip device constantly monitors the current passing through a circuit breaker, and when this current reaches an overcurrent state, issues a command to trip the circuit breaker. As this overcurrent tripping device, there are known two types: a mechanical type in which the overcurrent state detecting section is configured with a bimetal or an electromagnet, and an electronic type in which the overcurrent state detection section is configured with an electronic circuit. An electronic overcurrent tripping device consists of a current transformer that detects the passing current of a circuit breaker, an electronic circuit that monitors the current signal of this current transformer, and a drive current that is output from this electronic circuit when an overcurrent occurs. It is composed of a trip coil unit that operates at 100 kHz, and has the advantage of being easier to adjust the rated current and tripping operation characteristics than mechanical types, as well as being able to add various alarm 1 display functions. Fig. 4 shows a schematic configuration of a circuit breaker equipped with the above electronic overcurrent tripping device. A contactor 4, a movable contactor 5, an overcurrent tripping device 6, a terminal section 7 on the load side, an opening/closing mechanism section 8, an arc extinguishing chamber 9, and the like are housed. The overcurrent tripping device 6 consists of a current transformer 11 through which a conductor 10 connects the movable contact 5 and the terminal portion 7, an electronic circuit (not shown) mounted on a printed board, and a trip coil unit 12. When it is determined that the current detected by the flow device 11 is in an overcurrent state, the trip coil unit 12 acts on the opening/closing mechanism section 8 in response to the output of the electronic circuit, and opens the movable contact 5. [Problems to be Solved by the Invention] By the way, since the configurations of overcurrent tripping devices are different between mechanical and electronic types, conventional circuit breakers using mechanical overcurrent tripping devices (hereinafter referred to as a mechanical circuit breaker) and a circuit breaker using an electronic overcurrent trip device (hereinafter referred to as an electronic circuit breaker) are each constructed using a dedicated outer box and are separated. It was assembled on the line. However, if it becomes possible to share the circuit breaker body between mechanical and electronic types, parts such as case 1 and cover 2 can be shared, and the assembly line can also be used, which is advantageous in reducing costs. becomes. In particular, since electronic circuit breakers can be multi-functional, various functions are required depending on the purpose of use, which inevitably leads to high prices. If a type circuit breaker can be constructed, it will be easy to reduce costs. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an overcurrent tripping device for a circuit breaker that can configure an electronic circuit breaker by sharing a mechanical circuit breaker and a circuit breaker main body. be.

[Means to solve the problem]

This invention provides a molded case that can be attached to the load side of a circuit breaker main body, and a conductor having one end connected to a load side terminal part of the circuit breaker main body and the other end serving as a terminal part, and a current flowing through the conductor. It houses a current transformer that detects current transformer, and an electronic circuit that monitors the current signal of this current transformer and outputs a trip signal when it is determined that the current flowing through the conductor is in an overcurrent state, and the output of this electronic circuit is A trip coil unit is disposed within the circuit breaker main body to open and open the opening/closing mechanism of the circuit breaker main body in response to the trip coil unit.

[For use]

The parts of the electronic overcurrent tripping device, excluding the trip coil unit, are stored in a special molded case and installed on the load side of the circuit breaker main body, which is shared with the mechanical circuit breaker. This is the load side terminal section. Then, instead of the mechanical overcurrent tripping device, a trip coil unit for operating the opening/closing mechanism is disposed within the circuit breaker main body. Thereby, electronic circuit breakers with various functions can be freely configured using a circuit breaker main body prepared as a standard mechanical circuit breaker.

【Example】

1 to 3 show embodiments of the present invention, FIG. 1 is a cross-sectional side view of the essential parts of a circuit breaker equipped with the overcurrent tripping device of the present invention, and FIG. 2 is the essential parts. The plan view and FIG. 3 are perspective views of essential parts showing the trip characteristic setting section. Note that parts corresponding to those in the conventional example are given the same reference numerals. In FIGS. 1 and 2, 13 is a main body of a mechanical circuit breaker, and 14 is a terminal portion on the load side. On the other hand, 15 is a molded case that is attached to the load side of the circuit breaker body 13 and houses the parts of the electronic overcurrent tripping device other than the trip coil unit, and is composed of a case 16 and a cover 17. There is. Case 1
6 includes a current transformer 11 mounted on a printed board 17, and printed boards 18 and 19 equipped with an electronic circuit that monitors the current flowing through the conductor 10 via the conductor IO1 current transformer 11 that passes through the current transformer 11. etc. are stored. The conductor 10 is fastened to the case 16 from the back side with a screw 20, and one end of the conductor 10 is
The terminal a becomes a connecting end with the terminal section 14 of the circuit breaker main body 13, and the other end 10b becomes a new terminal section on the load side. As shown in FIG. 2, the case 16 of the overcurrent tripping device is attached to the circuit breaker body 13 by fitting a plate-shaped protrusion 16a with a swollen tip into a groove 1a of the same shape between the phases of the body case 1. The connecting end 10a of the conductor 10 is connected to the screw 2.
1, the terminal portion 11 is tightened from the back side of the case 16. Note that the groove 1a is provided for mounting an interphase barrier. The cover 17 is fastened to the case 16 with screws 22 from the front side thereof and with screws 23 from the back side of the case 16. Reference numeral 24 indicates a setting dial of the tripping operation characteristic setting section provided on the printed board 19, and 25 indicates a display disk that operates in conjunction with the setting dial.As shown in FIG. The user adjusts the setting dial 24 through the hole 27 while looking at the operation setting value. On the other hand, the trip coil unit 12 is disposed within the circuit breaker body 13 in close proximity to a crossbar (not shown) of the opening/closing mechanism section 8, and is connected to the printed board 18 by a lead wire 28. In such an electronic circuit breaker, when the current passing through the conductor 10 becomes overcurrent, the trip coil unit 12 is actuated by the output of the electronic circuit that receives the current signal from the current transformer 11, and its plunger (not shown) is activated. is the crossbar
is moved to open and close the opening/closing mechanism section 8. According to the illustrated configuration, a circuit breaker main body 13 shared with a mechanical circuit breaker is used, a trip coil unit 12 is installed in the main body 13 instead of a mechanical overcurrent tripping device, and a molded case is installed on the load side. 15 and conductor 1
An electronic circuit breaker can be manufactured by simply connecting 0 to the terminal portion 14. Therefore, it is possible to share parts and use a common assembly line, and also to use various electronic overcurrent trip devices with different functions without making any changes to the case 1 or cover 2 of the 13 main bodies. You will be able to choose freely according to your needs. Furthermore, it is also possible to sell the electronic overcurrent tripping device as a standalone unit, allowing the customer to convert a mechanical circuit breaker to an electronic one if necessary.

【Effect of the invention】

According to this invention, an electronic circuit breaker can be constructed using a circuit breaker body prepared as a standard mechanical type without preparing a circuit breaker body exclusively for electronic type. Costs can be reduced by standardizing and using assembly lines, and in addition to overcurrent tripping function, earth fault protection function, open phase protection function, advance prediction warning function,
You can now freely select electronic overcurrent trip devices equipped with various functions necessary for maintenance, management and control of power distribution systems, such as noise filter functions and power demand monitoring functions, using the same circuit breaker body. .

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of a circuit breaker equipped with an overcurrent tripping device according to the present invention, with main parts cut away, FIG. 2 is a plan view of the main parts, and FIG. FIG. 4 is a perspective view of a tripping operation characteristic setting section in an overcurrent tripping device, and a vertical cross-sectional view of a circuit breaker as a conventional example. 8... Opening/closing mechanism part, 10... Conductor, 11... Current transformer, 12... Trip coil unit, 13... Circuit breaker body, 14... Terminal part, 15... mold case.

Claims (1)

[Claims] 1) Inside a molded case that can be attached to the load side of the circuit breaker body, there is a conductor with one end connected to the load side terminal part of the circuit breaker body and the other end serving as the terminal part, and the current flowing through this conductor. A current transformer that monitors the current signal of the current transformer and an electronic circuit that outputs a trip signal when it is determined that the current flowing through the conductor is in an overcurrent state, and receives the output of this electronic circuit. 1. An overcurrent tripping device for a circuit breaker, characterized in that a trip coil unit is disposed within the circuit breaker body for opening and closing the opening/closing mechanism of the circuit breaker body.