JPH07147724A - Circuit breaker and test method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To save the labor of wiring and enable the withstand voltage or insulation resistance test between the phases of the main circuit of the circuit breaker for wiring. [Construction] The circuit breaker with a leakage warning function has a function of detecting an electric current flowing in the main circuit by the overcurrent detection elements 2a to 2c, has an overload / short-circuit protection function for the main circuit, and has a zero-phase current transformer 7. It has a function of detecting a current flowing in the main circuit and detecting a leakage by the leakage determination circuit 8. The main circuit of the circuit breaker for wiring and the external terminals 11a, 11b are connected, and the power supply terminals 9a, 9b and the external terminals 11a, 11b of the leakage determination circuit 8 are provided on the external terminal block of the circuit breaker for wiring. 9a, 9b and the external terminals 11a, 11b lead wire 1
Connect by 2a and 12b. In the withstand voltage or insulation resistance test, the lead wires 12a and 12b are removed and the leakage determination circuit 8 is disconnected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker having a function of monitoring an electric leakage current in addition to an overload / short circuit protection function and a test method for the circuit breaker.

[0002]

2. Description of the Related Art In the related art, for example, a circuit breaker for wiring with an earth leakage warning function, the power supply for an earth leakage determination circuit is directly supplied from the main circuit of the circuit breaker for wiring, or an external power supply terminal is provided and its external terminal is provided. It was a structure to be supplied from an external power source via.

[0003]

By the way, when the power supply for the leakage determination circuit is directly supplied from the main circuit of the circuit breaker for wiring, the wiring for supplying power to the leakage determination circuit can be omitted. When performing an inter-phase insulation resistance test (Meg measurement) or withstand voltage test (breakdown voltage), which are test items as a circuit breaker, an overvoltage is applied to the electronic components of the earth leakage judgment circuit. There was a problem that the test had to be done separately.

Further, since the method of supplying the power supply of the leakage determination circuit from the external power supply terminal is the external power supply system, the breakdown voltage between the phases can be maintained without applying an overvoltage to the electronic components of the leakage determination circuit.
It becomes possible to perform the MEG measurement and completely meet the standard of the circuit breaker for wiring, but there is a problem that the trouble of external wiring occurs.

The present invention has been made in view of the above problems, and an object thereof is a circuit breaker capable of measuring the withstand voltage and MEG between the phases of the main circuit of the circuit breaker without the need for wiring, and a test thereof. There is a way to provide.

[0006]

SUMMARY OF THE INVENTION A circuit breaker according to the present invention has a main circuit overload / short-circuit protection function by detecting a current flowing in a main circuit by an overcurrent detection element, and a main circuit by a zero-phase current transformer. In a circuit breaker having a function of detecting a current flowing in a circuit and detecting a leakage by a circuit, a main circuit of the circuit breaker and an external terminal are connected, and the leakage judgment is made on an external terminal block of the circuit breaker. A power supply terminal of the circuit and the external terminal are provided, and the power supply terminal and the external terminal are connected by a lead wire or a connection terminal. (Claim 1) The test method in this case is characterized in that a lead wire or a connection terminal between the power supply terminal and the external terminal is removed to perform a withstand voltage test or an insulation resistance test of the circuit breaker. (Claim 2) Further, the circuit breaker according to the present invention has a function of detecting a current flowing in the main circuit by the overcurrent detection element to protect the main circuit from overload and short-circuit, and a zero-phase current transformer in the main circuit. In a circuit breaker having a function of detecting a flowing current and detecting a leakage by a leakage determination circuit, a switch is provided in the middle of a circuit connecting the main circuit and the leakage determination circuit. (Claim 3) The test method in this case is characterized in that the withstand voltage test or the insulation resistance test of the circuit breaker for wiring is performed by turning off the switch between the power supply terminal and the external terminal. (Claim 4) Further, a cover is provided which is attached to the main body of the circuit breaker to turn off a switch provided between the main circuit and the leakage determination circuit and which is removed to turn on the switch. (Claim 5) In this case, the circuit breaker for wiring is subjected to a withstand voltage test or an insulation resistance test with the cover attached. (Claim 6)

[0007]

According to the circuit breaker of the present invention, by connecting / disconnecting the lead wire or the connection terminal and turning on / off the switch, the power is supplied to the leakage determination circuit and the main circuit of the leakage determination circuit is operated. Can be easily separated.
(Claims 1 and 3) According to the circuit breaker testing method of the present invention, an overvoltage is applied to the electronic component of the leakage determination circuit by removing the lead wire or the connection terminal or turning off the switch. Without withstanding voltage or insulation resistance test. (Claims 2 and 4) Further, by attaching the cover to the circuit breaker body, the switch can be turned off to safely perform the withstand voltage or insulation resistance test between the phases of the main circuit, and then by removing the cover, You can prevent forgetting to return the switch. (Claims 5 and 6)

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of a circuit breaker with a leakage warning function according to the present invention. Figure 2
(A) And (b) is a front view and a side view which show the external terminal block of the circuit breaker with a leakage warning function which has the circuit structure of FIG. In FIG. 1, the circuit breaker for wiring corresponds to each phase, the power source side terminals 1a, 1b, 1c, the main circuit switch 2a,
2b, 2c and load side terminals 3a, 3b, 3c, and main circuit switching parts 2a, 2b, 2c and load side terminals 3a, 3b,
An overcurrent detecting element 4a, 4b, 4c for detecting an overcurrent of the main circuit and a zero-phase current transformer 7 for detecting a leakage current of the main circuit are provided between the 3c and 3c. Overcurrent detection elements 4a, 4
b and 4c detect the current from each phase, and the detection output is input to the overcurrent determination unit 5. When the overcurrent determination unit 5 determines whether the detected current is an overcurrent and determines that it is an overcurrent, it outputs a signal to the trip device 6 to output the main circuit opening / closing units 2a, 2b,
2c is opened to protect the load connected to the load side.
The detection output of the zero-phase current transformer 7 is input to the leakage determination circuit 8,
If the detected current is a leakage current in the leakage determination circuit 8, and if it is determined to be a leakage current, an alarm signal is output to the outside via a leakage alarm relay (not shown), or provided in the circuit breaker for wiring itself. Activate the earth leakage warning indicator. 10
Reference numerals a and 10b are leakage alarm output terminals that detect leakage and output a signal to the outside. The leakage determination circuit 8 is provided with power supply terminals 9a and 9b for supplying power to operate the leakage detection circuit 8. The power supply terminals 9a and 9b are external terminals connected to the load side terminals 3a and 3c of the main circuit. Terminals 11a, 11
b is connected via a lead wire or connection terminals 12a and 12b, and power is supplied from the main circuit to the leakage determination circuit 8.

The external terminal block 1 shown in FIGS. 2 (a) and 2 (b)
3 is provided on the side surface of the main body of the circuit breaker for wiring, and is provided with external terminals 11a and 11b connected to the main circuit, power supply terminals 9a and 9b of the leakage determination circuit 8, and the external terminals 11a and 11b. Power supply terminals 9a and 9b are lead wires 1
Power is supplied to the main circuit to the leakage warning circuit 8 by being connected by 2a and 12b.

As a result, the power is normally supplied to the leakage determination circuit 8, but when the withstand voltage / Meg measurement is performed, the phases of the main circuit can be made independent by removing the lead wires 12a and 12b. Therefore, the breakdown voltage / Meg measurement can be performed without applying an overvoltage to the electronic components of the leakage determination circuit 8. In this case, the lead wires 12a and 12b can be easily attached and detached even if connection terminals are used.

FIG. 3 shows another embodiment according to the present invention, in which the power supply terminals 9a and 9b of the leakage determination circuit 8 and the load side terminals 3a,
The terminals 14a and 14b connected to the main circuit on the 3c side are connected to the terminals of the connector 15, and the terminals 9 of the connector 15 are connected.
The switches a, 9b, 14a and 14b are turned on / off by a changeover switch 16 which is a slide switch.

In this case, instead of the changeover switch 16, a short-circuit plug 17 is used as shown in FIG.
By attaching and detaching, the terminals 9a, 9 of the connector 15
It is also possible to configure so that b, 14a and 14b are short-circuited or opened.

According to the embodiment shown in FIGS. 3 and 4, the switch 16 is normally turned on or the short-circuit plug 17 is inserted so that power is supplied to the leakage determination circuit and the switch 16 is turned on. Turn off or short-circuit plug 17
By disconnecting, the leakage determination circuit 8 and the main circuit are separated, and the breakdown voltage / Meg measurement can be performed.

FIGS. 5 (a) to 5 (c) show another embodiment in which a changeover switch composed of a slide switch is used, and a cover made of an insulating material is attached to the main body of the circuit breaker for wiring when measuring withstand voltage and MEG. 18 is attached and this cover 1
8 is attached, the knob 19a having the inclined surface of the changeover switch 19 moves along the inclined concave portion 18a formed inside thereof and is turned off. When the cover 18 is removed, the return spring 20 causes the changeover switch 19 to return to its original position. It is designed to return to the position and turn on.

Therefore, according to this embodiment, when the cover 18 is attached, the leakage determination circuit is disconnected from the main circuit, and when the cover 18 is removed, power is supplied to the leakage determination circuit. It is possible to safely perform the MEG measurement, and it is possible to prevent forgetting to return the changeover switch 19 after the test.

FIG. 6 shows another embodiment of the present invention.
The push button switch 21 is used as a switch. The push button switch 21 can turn on / off the power supply for the main circuit and the leakage determination circuit.
A return spring 22 for returning 1 is provided, and when the push button switch 21 is released, the push button switch 21 automatically returns to supply power again to the leakage determination circuit. Therefore, in this embodiment, the push button switch 21
Press to keep the power to the main circuit and the leakage determination circuit off, and measure the breakdown voltage and MEG.

7A and 7B, the push button 24 and the changeover switch 25 are formed separately, and the push button 24 is arranged so as to be flush with the upper surface of the cover of the main body of the circuit breaker for wiring. It is another embodiment of the case where a switch is used, which is a cover 23 made of an insulator when the withstand voltage and the MEG are measured.
When the cover 23 is attached, the push button 24 is attached along the convex portion 23a formed inside.
When the cover 25 is removed by pressing the switch 25 and the switch 25 to turn it off, the return springs 26 and 27 return the push button 24 and the switch 25 to their original positions and turn them on.

In this embodiment, with the cover 23 attached, the leakage determination circuit is disconnected from the main circuit,
Withstand voltage and MEG measurements can be performed safely, and with the cover 23 removed, the push button 24 and the switch 25
Is restored and power is supplied to the leakage determination circuit, so that it is possible to prevent forgetting to return the push button 24 and the switch 25.

In the above embodiment, the circuit breaker for wiring with the leakage warning function has been described, but the present invention supplies the power of the leakage determination circuit from the main circuit and detects and determines the leakage of the main circuit. Of course, the same can be applied to other circuit breakers such as an earth leakage breaker that trips the main circuit.

[0020]

According to the circuit breaker and the method of testing the same of the present invention, power can be easily supplied to the leakage determination circuit of the circuit breaker or the leakage determination circuit can be used as the main circuit without the need for wiring. In addition, it is possible to easily supply power to the leakage judgment circuit by attaching a cover or disconnect the leakage judgment circuit from the main circuit when performing a withstand voltage or insulation resistance test between phases. The test can be done safely.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of a circuit breaker according to the present invention.

2 is a front view and a side view showing an external terminal block of the circuit breaker of FIG.

FIG. 3 is a circuit configuration diagram showing another embodiment of the present invention.

FIG. 4 is an exploded perspective view showing another embodiment of the present invention.

5A and 5B show a state in which a cover is attached to the circuit breaker according to the present invention, FIG. 5A is an exploded view showing a state before the cover is attached, and FIG. 5B is an enlarged sectional view showing a main part of FIG. , (C) is a sectional view showing a state in which a cover is attached.

FIG. 6 is a circuit configuration diagram showing another embodiment of the present invention.

7A and 7B show another embodiment of the present invention, in which FIG. 7A is a sectional view showing a state before a cover is attached, and FIG. 7B is a sectional view showing a state in which the cover is attached.

[Explanation of symbols]

1a, 1b and 1c are power supply side terminals, 2a, 2b and 2c are main circuit switching parts, 3a, 3b and 3c are load side terminals, 4a and 4
b and 4c are overcurrent detection elements, 5 is an overcurrent determination unit, 6 is a trip device, 7 is a zero-phase current transformer, 8 is a leakage determination circuit, 9a,
9b is a power supply terminal, 11a and 11b are external terminals, 12a,
12b is a lead wire or a connection terminal, 13 is an external terminal block, 14a and 14b are terminals, 15 is a connector, 16 is a changeover switch, 17 is a short-circuit plug, 18 is an insulating cover, 19 is a changeover switch, and 21 is a push button. Button switch,
Reference numerals 22, 26 and 27 are return springs, 23 is an insulating cover, 24 is a push button, and 25 is a switch.

Claims (6)

[Claims] 1. An overcurrent detection element detects a current flowing in a main circuit to provide an overload / short-circuit protection function for the main circuit, and a zero-phase current transformer detects a current flowing in the main circuit to detect a leakage current. In the circuit breaker having a function of detecting, the main circuit of the circuit breaker and an external terminal are connected, and the external terminal block of the circuit breaker is provided with the power supply terminal and the external terminal of the leakage determination circuit, A circuit breaker in which a power supply terminal and an external terminal are connected by a lead wire or a connection terminal. 2. The circuit breaker test according to claim 1, wherein a lead wire or a connection terminal between the power supply terminal and the external terminal is removed to perform a withstand voltage test or an insulation resistance test of the circuit breaker. Method. 3. An overcurrent detection element has a function of detecting a current flowing in the main circuit to protect the main circuit from overload and short-circuit, and a zero-phase current transformer detects the current flowing in the main circuit to detect the leakage current. A circuit breaker having a function of detecting leakage, wherein a switch is provided in the middle of a circuit connecting the main circuit and the leakage determination circuit. 4. The method for testing a circuit breaker according to claim 3, wherein a switch between the power supply terminal and the external terminal is turned off to perform a withstand voltage test or an insulation resistance test of the circuit breaker. 5. A cover is provided which is attached to the main body of the circuit breaker to turn off a switch provided between the main circuit and the leakage determination circuit, and which is removed to turn on the switch. Circuit breaker described. 6. The method for testing a circuit breaker according to claim 5, wherein a withstand voltage test or an insulation resistance test is performed on the circuit breaker with the cover attached.