JP3138340B2 - Circuit breaker for ground fault protection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a circuit breaker for ground fault protection by adding a simple operation and inexpensive parts.
The present invention relates to a configuration in which a circuit can be interrupted even when an overcurrent is applied due to an overload and, in some cases, abnormal heat is generated due to improper tightening of a terminal.

[0002]

2. Description of the Related Art FIG.
Conventionally, a ground fault / overload protection / ground fault circuit breaker has a bimetal 1 attached as a part of a main conductor to at least one pole between a power source side and one load side, and a contact device is provided by bending of the bimetal 1 due to temperature rise due to overcurrent. , Which is a separate device from the trip device 3 due to a ground fault, which is costly.

Further, the bimetal 1 requires a deformation force corresponding to the trip load of the contact trip mechanism, but the trip load varies greatly depending on the individual, and it takes time to adjust the trip time due to overcurrent. ing.

[0004]

SUMMARY OF THE INVENTION In view of the above, the present invention utilizes a tripping device due to a ground fault in a circuit breaker for ground fault protection, and applies overcurrent or poor terminal tightening due to overload or the like. Detects temperature rise due to abnormal heat generation, etc., or detects a change in the magnetic field of the conductor due to overcurrent application due to overload, etc., and directly applies a voltage to the tripping device to operate the tripping device and cut off the circuit It is configured by adding simple and inexpensive means.

[0005]

[Function] The conductor temperature rises due to overcurrent conduction due to overload, heat generation due to terminal tightening failure, etc., or the temperature inside the circuit breaker increases, or the conductor magnetic field increases due to overcurrent conduction due to overload, etc. , Directly apply the voltage to the tripping device due to the ground fault of the ground fault protection circuit breaker and operate it.
Disconnect and disconnect contacts.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment according to the second aspect of the present invention. FIG. 2 is an explanatory diagram of an operation in an overload state, for example, according to FIG. In FIG. 1, reference numeral 7 denotes a main conductor that penetrates through the zero-phase current transformer 5, and when a ground fault occurs, the zero-phase current transformer 5 is formed due to an imbalance in the current flowing through the two-pole main conductor 7 due to the ground fault. A voltage is applied to the trip unit 3 by the amplifier unit 4, and the circuit breaker is tripped.

Reference numeral 8 denotes an element whose shape changes according to temperature, such as a bimetal or a shape memory alloy, according to the present invention, one end of which is electrically connected to the main conductor 7 by soldering, screwing, spot welding, or the like, and the other end thereof. The main conductor 7 of the trip device 3 due to the ground fault is separated from the bare conductor of the power supply line 9 on the other pole side by a gap 1.
They are arranged facing each other with a distance of 0.

The gap 10 between the element 8 and the bare charged portion of the power supply line 9 is formed by the power supply line 9 when the element 8 is deformed due to a rise in the temperature of the main conductor or the inside of the case due to energization below the rated current value of the circuit breaker. The gap does not come into contact with the bare charging portion, but is contacted by deformation due to temperature rise due to heat generation due to abnormalities such as overcurrent conduction and improper tightening of electrical connection terminals.

In FIG. 2, for example, if it is assumed that the load 11 is in an overloaded state and an overcurrent exceeding the rated current value is flowing through the main conductor 7, the temperature in the main conductor 7 or the inside of the housing further rises, and 8 becomes large and the power line 9 of the trip device 3
Contact bare live parts.

When the element 8 and the bare charging portion of the power supply line 9 of the tripping device 3 come into contact with each other, a voltage is applied to the tripping device 3 and the tripping device 3 operates to trip the circuit breaker.

FIG. 3 is a block diagram of an embodiment according to a third embodiment of the present invention, and FIG. 4 is an explanatory diagram of an operation in, for example, an overload state according to FIG. 3, wherein an iron material whose magnetic force changes due to a change in a magnetic field. An electromagnet device 12 made of a homomagnetic material is attached to the main conductor 7, and the main conductor 7 of the tripping device 3 is connected to the power supply line 9 on the other pole side of the conductive member 1 made of a phosphor bronze plate or the like.
3 is electrically connected by soldering, screwing, spot welding, or the like, and a magnetic member 14 is attached to the other end at a portion facing the electromagnet device 12.
2 and a gap 15 and a gap 1 between the bare charged portion of the main conductor 7 and
6 are arranged opposite to the electromagnet device 12 and the main conductor 7.

The gap 16 and the gap 16 are narrower than the gap 16. The gap 15 does not attract the magnetic member 14 by the magnetic force to the electromagnet device 12 in the main conductor 7 when the main conductor 7 is energized below the rated current value of the circuit breaker. 7 is a gap that contacts the bare charging section.

In FIG. 4, for example, if it is assumed that the load 11 is in an overloaded state and an overcurrent of a rated current or more is flowing through the main conductor 7, the magnetic field of the main conductor 7 increases and the electromagnet device 1
The magnetic force of No. 2 becomes strong, and the magnetic member 14 is attracted, and the member 13 comes into contact with the main conductor 7.

When the member 13 comes into contact with the main conductor 7, a voltage is applied to the tripping device 3, and the tripping device 3 operates to trip the circuit breaker.

[0016]

As described above, according to the present invention, there is provided means for operating the tripping device due to ground fault due to abnormal heat generation inside the circuit breaker or due to an increase in the magnetic field of the conductor during overcurrent application. By simply adding parts to the conventional ground fault protection circuit breaker, it is possible to provide a ground fault protection circuit breaker that can operate even at an overcurrent at a low cost. Since the tripping for overcurrent is not affected by the trip load of the contact tripping mechanism, the work of adjusting the tripping time is easy, and the ground fault and overload protection for earth fault and overload protection with high accuracy of tripping time for overcurrent There is an effect that a circuit breaker can provide.

In the illustrated example, two poles are shown.
A similar effect can be obtained with a circuit breaker for protecting a ground fault, for a pole and a pole.

Further, the operating means of the ground fault tripping device according to the present invention can be applied to any type and rating of a ground fault protection circuit breaker. There is also an effect that inexpensive products can be provided in general.

[Brief description of the drawings]

FIG. 1 is a block diagram of a second embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation in an overload state in FIG.

FIG. 3 is a block diagram of a third embodiment of the present invention.

FIG. 4 is an operation explanatory diagram in an overload state in FIG. 3;

FIG. 5 is a configuration diagram showing a structure of a conventional earth leakage breaker for ground fault / overload protection.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 Bimetal 2 Tripping device due to overload 3 Tripping device due to ground fault 4 Amplifying unit 5 Zero-phase current transformer 6 Contact device 7 Main conductor 8 Element whose shape changes according to temperature according to the present invention 9 Earth tripping device due to ground fault Power line 10 Gap between the element whose shape changes according to temperature according to the present invention and the bare charging portion of the power line of the trip unit due to ground fault 11 Load 12 Electromagnet device according to the present invention 13 Elastic conductive member according to the present invention 14 Magnetic member attached to the conductive member 15 Gap between the magnetic member attached to the conductive member and the electromagnet device 16 Gap between the conductive member and the main conductor In the drawings, the same reference numerals represent the same parts.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-9975 (JP, A) JP-A-60-55821 (JP, A) JP-A-61-10826 (JP, A) JP-A-4- 178111 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01H 83/02

Claims (3)

(57) [Claims] A contact device, a mechanism for opening and closing the contact device, a zero-phase current transformer for detecting a ground fault current, an amplifying unit, and a ground fault in a body constituted by a base and a cover. In a ground fault protection earth leakage circuit breaker that has a tripping device that separates, when an overcurrent is applied due to an overload or the like, the trip device that separates the contact device due to a ground fault does not pass through a zero-phase current transformer or an amplifier. A circuit breaker for ground fault protection, comprising means for directly applying a current, operating a tripping device and tripping a circuit breaker. 2. The means for applying a voltage to the tripping device and operating the tripping device electrically connects an element whose shape changes with temperature to a main conductor of a pole whose power supply line of the tripping device is not directly connected to the main conductor. 2. The circuit breaker for ground fault protection according to claim 1, wherein the circuit breaker is configured to apply a voltage to the tripping device according to a change in the shape of the element due to temperature and to operate the tripping device. 3. A means for applying a voltage to the tripping device and operating the tripping device includes attaching an electromagnet device whose magnetic force changes due to a change in a magnetic field of the main conductor due to overcurrent conduction to one main conductor, and providing a power line of the tripping device. Is electrically connected to a power supply line of a pole which is not directly connected to the main conductor, a conductive member having an elastic force including a magnetic member so as to face the electromagnet device, and is attracted by a change in magnetic force due to a magnetic field. 2. The circuit breaker for ground fault protection according to claim 1, wherein the circuit breaker is configured to operate by applying a voltage to the disconnecting device. [0001]