JP2001345038A - Circuit-breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an instant shutdown type circuit-breaker which shares many parts installed at a circuit-breaker main body of a standard product as much as possible and which has no overload/open-phase trip function while retaining a trip test function by changing only a small part of the parts. SOLUTION: For the circuit-breaker which has a breaker part 8, an open-close mechanism part 9, a thermal type overload/open-phase trip device 10, and an electromagnetic type instant trip device 11 in a case 1 as the standard equipment, a push-shifter of a differential-mode shifter mechanism 13 which is a component of the thermal type overload/open-phase trip device is replaced by a dummy shifter 15A which has a structure wherein an arm part is removed from a push-shifter with the arm of the standard product, and the overload/open- phase trip function is made unable to function while the trip test function is being secured, and further, an adjustment dial of the rated current facing onto a case cover in combination with a bimetal 14 for temperature correction is replaced by a dummy dial 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for overload and overcurrent protection of a motor for an auto breaker or the like.

[0002]

2. Description of the Related Art Uniform standards have been established for the auto breaker, which is a major component of low-voltage power distribution equipment, and manufacturers currently produce circuit breaker bodies as standard products in series according to breaking capacity. is there. Next, the structure of the standard circuit breaker is shown in Figs. 3 and 4 (a) and (b).
Will be described. First, in FIG. 3, 1 is a circuit breaker case (mold case), 2 is a power supply side main circuit terminal,
Is a main circuit terminal on the load side, 4 is a handle for opening / closing operation, 5 is an adjustment dial for adjusting the rated current of a thermal overload / open phase trip device described later, 6 is a hole for a trip test, and 7 is a nameplate. In case 1, as shown in FIGS. 4 (a) and (b),
A breaking portion 8 comprising a movable contact 8a, a fixed contact 8b, and an arc-extinguishing chamber 8c; an opening / closing mechanism 9 serving as a toggle link mechanism for driving the movable contact 8a of the breaking portion 8 to an opening / closing position; The circuit breaker is assembled by assembling the open-phase tripping device 10 and the electromagnetic instantaneous tripping device 11 as standard as shown in the drawing.

Here, a thermal type overload / open phase trip device 1
Numeral 0 denotes a main bimetal with a heater connected to each phase of the main circuit, and a differential shifter mechanism 13 connected to the main bimetal operating end (upper end) of each phase to detect the movement of the bimetal.
And a temperature-compensating bimetal (hairpin) 14 also serving as a release lever that connects the output end of the differential shifter mechanism 13 and the latch receiver incorporated in the opening and closing mechanism 9.

The above-mentioned differential shifter mechanism 13 is a slide-type push shifter 15 laid on the left and right sides along the arrangement of the main bimetals 12 of each phase and fitted and supported in the grooves of the phase interval wall 1b of the case 1. , A pull shifter 16 and a combination of a push shifter 15 and an output lever 17 which is oscillably pin-coupled across the upper surface of the pull shifter 16. It has L-shaped arms 15a and 16a protruding toward the bimetal 12, and the ends of the arms face both surfaces of the main bimetal 12 at the assembly position.

The adjusting dial 5 protrudes from a dial hole opened in the cover 1a of the case 1 as shown in FIG. 3, and an adjusting groove 5a for inserting a screwdriver or the like and turning the dial is formed on the top surface thereof. Further, an adjustable rated current value is printed on the periphery of the hole of the cover 1a in accordance with the arrow printed on the top surface of the dial 5. The operation of a tripping device having such a configuration is well known, and is disclosed, for example, in Japanese Patent Application No. 2000-689 previously proposed by the same applicant of the present invention.
No. 79 also describes this in detail. That is, an overload current flows in the main circuit, and the main bimetal 12 bends in a fixed direction, and accordingly, the push shifter 1 of the differential shifter mechanism 13 is driven.
5, When the pull shifter 16 is displaced in the direction of the arrow, the output lever 17 pushes the tip of the temperature compensating bimetal 14. As a result, the temperature compensating bimetal 14 rotates clockwise about the support shaft 14a and pushes the latch receiver to the release position. As a result, the opening / closing mechanism 9 trips to move the movable contact 8a of the cutoff section 8. Opens and shuts off the main circuit current. When a phase loss occurs in the main circuit, the push shifter 15 and the pull shifter 16 of the differential shifter mechanism 13 operate differentially, so that the output lever 17 uses the connection pin with the pull shifter as a fulcrum. The circuit breaker is rotated counterclockwise to push the temperature compensating bimetal 14, and the circuit breaker is tripped as described above.

On the other hand, the electromagnetic instantaneous trip device 11 comprises a trip coil 11a connected to the main circuit, a yoke 11b,
It comprises a plunger 11c and a tripping lever 11d driven by the plunger 11c. When an overcurrent flows through the main circuit due to a short circuit accident or the like, the plunger 11c performs a suction operation and the tripping lever 11d engages the latch receiver of the opening / closing mechanism unit 9. Release
Instantaneously trip the circuit breaker.

When a trip test of the circuit breaker is performed in a non-energized state, a driver or the like is inserted into the trip test hole 6 shown in FIG.
The output lever 17 (see FIG. 4) (the output lever is provided with a projection on which the tip of the driver is hooked) is pushed to the operating position. As a result, the temperature compensating bimetal 14 rotates to release the latch receiver of the opening / closing mechanism 9, and the circuit breaker is tripped.

[0008]

By the way, a standard circuit breaker equipped with the thermal overload / open-phase tripping device 10 and the electromagnetic instantaneous tripping device 11 as described above,
When used in a power distribution circuit with a motor that has a long start time as a load, the start time of the motor, the starting current, and the overload protection characteristics of the circuit breaker cannot be coordinated, and the circuit breaker trips during the start of the motor. May be done.

Therefore, in a power distribution circuit using a motor having a long start time as a load, an overload / open phase trip function is eliminated so that the circuit breaker does not inadvertently trip during the start of the motor. In some cases, a slow-moving thermal relay is connected separately to provide overload protection. Conventionally, the differential shifter mechanism 13, the temperature compensating bimetal 14, and the adjustment dial 5 are removed from the standard circuit breaker body shown in FIG. It does not work (however, if the main bimetal 12 connected to the main circuit is removed, the circuit constant of the circuit breaker will change and the operating characteristics will change, so the main bimetal is left) The cover of the case 1 is pulled out of the adjustment hole 5 and the trip test hole 6 shown in FIG.
A circuit breaker with a special specification (instantaneous breaker method) replaced with a case cover without a cover has been manufactured.

However, as a variation of the circuit breaker as described above, the conventional circuit breaker in which the parts of the overload / open-phase trip device are removed from the standard circuit breaker body and the case is further changed is a standard circuit breaker. However, there are problems in cost and function as described below. That is, (1) Since the cover of the case is different from the standard product, it is necessary to prepare a new mold and manufacture the cover, thereby increasing the cost.

(2) Since the differential shifter mechanism 13 has been removed, a trip test using the differential shifter mechanism cannot be performed. SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and requires only replacement of a part of a circuit breaker main body equipped with a thermal overload / opening trip device and an electromagnetic instantaneous trip device as standard equipment. It is an object of the present invention to provide a circuit breaker of an instantaneous circuit breaker type applied to a motor having a long start-up time while ensuring a test function and preventing an overload / open-phase trip function from operating, with almost no increase in cost.

[0012]

According to the present invention, in order to achieve the above object, according to the present invention, a shut-off portion, an opening / closing mechanism, a thermal overload / open phase trip device, and an electromagnetic instantaneous trip are provided in a case. A circuit breaker equipped with a disconnecting device as standard, wherein said thermal overload / open phase trip device is connected to each phase of a main circuit with a main bimetal, and a differential shifter mechanism for detecting movement of the main bimetal. It consists of a combination of a temperature compensating bimetal that also functions as a release lever that connects the output end of the differential shifter mechanism and the latch receiver of the opening / closing mechanism, and a rated current adjustment dial. A slide-type push shifter and pull shifter with arms on both sides of a main bimetal of each phase, and an output lever straddling the push shifter and pull shifter. ) Operating shifter mechanism The push shifter is assembled by replacing the push shifter of the standard product with a dummy shifter having a structure in which an arm portion is deleted from the push shifter of the standard product, and constitutes a circuit breaker of an instantaneous shutoff method without an overload / open phase trip function. 1).

(2) In addition to the above configuration, the dial for adjusting the rated current provided on the cover of the case is replaced with a dummy dial having no adjusting function. According to the above configuration, of the components incorporated in the standard circuit breaker body, two components of the push shifter of the differential shifter mechanism and the adjustment dial are slightly inserted into the dummy shifter having no arm portion and the adjustment groove into which the driver is inserted. By simply replacing the dummy dial with no one, it is possible to change to a specification that works only for instantaneous trip without overload / open phase trip. In addition, since the output lever of the differential shifter mechanism is supported between the dummy shifter and the pulling shifter in the same manner as the standard product, a trip test function similar to that of the standard circuit breaker body can be secured.

Further, by replacing the standard adjustment dial with a dummy dial, the standard case can be used as it is, and since the adjustment groove is not formed on the top surface of the dummy dial, the circuit breaker is overloaded. It can be recognized that it is an instantaneous shut-off method without the open-phase trip function.

[0015]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to (a) and (b) and the embodiment shown in FIG. In the drawings of the embodiment, members corresponding to those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. In other words, the circuit breaker of the illustrated embodiment is similar to the main body of the standard circuit breaker shown in FIG. 4 except for some parts, and has the same breaking section 8, switching mechanism 9, thermal overload / opening reduction. The components constituting the detaching device 10 and the electromagnetic instantaneous trip device 11 are incorporated in the case 1. The push shifter 15 of the differential trip mechanism 13 and the push shifter 15 are slightly different from the standard product of FIG. Two components of the rated current adjusting dial 5 are replaced with a dummy shifter 15A and a dummy dial 5A.

Here, the dummy shifter 15A is provided from the standard push shifter 15 (see FIG. 4) to the main bimetal 1 of each phase.
2 is a flat plate having a shape in which an arm portion 15a protruding toward the casing 2 is removed. The flat plate is slidably guided and supported in a concave groove formed in the phase space wall 1b of the case 1 like a standard product. The dummy dial 5A has the same outer shape as the standard adjustment dial 5 (see FIG. 4), but its top surface is a flat surface. Adjustment groove 5a of the product
Is deleted. As shown in FIG. 2, a cover 1a of the circuit breaker case 1 employs a standard product similar to that of FIG. 3 as it is, and a trip test hole 6 is opened on the upper surface thereof. Therefore, it is not necessary to prepare a new case mold. However, the current value is not printed on the periphery of the dial hole from which the dummy dial 5A protrudes.

In the above configuration, the main bimetal 12 and the dummy shifter 15A are not connected to each other. Therefore, even if an overload current continuously flows through the main circuit and the main bimetal 12 is greatly bent, the differential shifter mechanism is not provided. The circuit breaker 13 does not perform a trip operation because the circuit breaker 13 is stopped without making a differential. Further, even when a phase loss occurs in the main circuit, the differential shifter mechanism 13 does not operate.

Therefore, when the circuit breaker is overloaded /
If an instantaneous shut-off method without the open-phase trip function is applied to a power distribution circuit that uses a motor with a long startup time as a load as described above, the circuit breaker trips carelessly during the start-up of the motor. Disappears. In the trip test of the circuit breaker, a trip operation test can be performed by inserting a driver into a test hole 6 opened in the case 1 in the same manner as a standard product.

[0019]

As described above, according to the present invention, a circuit breaker equipped as standard with a thermal overload / open-phase tripping device and an electromagnetic instantaneous tripping device can be provided with a small number of parts. Can be changed to an instantaneous circuit breaker system without the overload / open-phase trip function while leaving the trip test function. This makes it applicable to power distribution equipment that uses a motor with a long startup time as a load. The circuit breaker can be provided with almost no increase in cost.

[Brief description of the drawings]

1A and 1B are internal structural views of a circuit breaker according to an embodiment of the present invention, wherein FIG. 1A is a plan view with a case k cover removed, and FIG. 1B is a longitudinal side view of FIG.

FIG. 2 is a plan view showing a state where a case cover is attached to the circuit breaker of FIG. 1;

FIG. 3 is a plan view of a standard circuit breaker.

FIG. 4 is a diagram showing the internal structure of the circuit breaker shown in FIG. 3, wherein (a) is a plan view showing a state in which a cover of a case is removed, and (b).
Is the vertical side view of (a)

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 1a Cover 5 Standard adjustment dial 5A Dummy dial 6 Trip test hole 8 Breaker 9 Opening / closing mechanism 10 Thermal overload / open-phase tripping device 11 Electromagnetic instantaneous tripping device 12 Main bimetal 13 Differential shifter Mechanism 14 Temperature compensating bimetal 15 Standard push shifter 15A Dummy shifter 16 Pull shifter 17 Output lever

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Koji Nomura 1-1-1, Tanabe-Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa F-term within Fuji Electric Co., Ltd. 5G030 BA02 BA05 FA02 FB03 FC02 FC03 FC05 XX07

Claims (2)

[Claims] 1. A circuit breaker having a shut-off portion, an opening / closing mechanism, a thermal overload / open-phase trip device, and an electromagnetic instantaneous trip device in a case as standard equipment, wherein the thermal breaker is provided. A main bimetal connected to each phase of the main circuit by the load / open phase trip device, a differential shifter mechanism for detecting the movement of the main bimetal, and between an output end of the differential shifter mechanism and a latch receiver of the switching mechanism. The standard differential shifter mechanism consists of a combination of a temperature compensating bimetal that also functions as a release lever and a rated current adjustment dial. The push-shifter of the actuating shifter mechanism in the slide-type push-shifter with arm, pull-shifter, and the output lever that straddles the push-shifter and pull-shifter have their arms removed from the standard push-shifter. Structural Circuit breaker being characterized in that so do not work overload / open-phase tripping function by replacing Mishifuta. 2. The circuit breaker according to claim 1, wherein the adjustment dial for the rated current is replaced with a dummy dial having no adjustment function.