JP3124452B2 - Single-phase three-wire circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-phase three-wire circuit breaker which detects an unbalanced voltage applied to a load device due to a neutral phase loss of a single-phase three-wire circuit and cuts off a main circuit. And a test circuit for confirming the operation of the neutral line open phase protection function.

[0002]

2. Description of the Related Art Conventionally, a single-phase three-wire circuit breaker 11 has, as shown in FIG.
Resistors R13 and R14, which are pseudo resistors, are connected between L2 and a test switch T is connected to these resistors R13 and R14.
S, the changeover switch SW11 and the voltage dividing circuit 12 were connected. In the normal abnormal voltage monitoring state, the changeover switch SW1
By switching 1 to the contact b, the voltage of the main circuit is divided by the voltage dividing circuit 12 composed of the resistors R11 and R12 and applied to the abnormal voltage detecting circuit IC11, and a voltage corresponding to a preset trip voltage is applied. When the trip coil TC
The tripping mechanism 14 was operated by the excitation of No. 11 to cut off the main circuit. Further, the test circuit 13 disconnects the connection with the neutral line N by switching the changeover switch SW11 from the b-contact to the a-contact, connects to the resistors R13 and R14, and turns on the test switch TS, thereby turning on the test switch TS. Voltage detection circuit IC11 based on the voltage division ratio of devices R13 and R14
A voltage corresponding to the trip voltage is applied to the abnormal voltage input terminal of the device, the tripping mechanism 14 is operated by the output of the abnormal voltage detection circuit IC11 and the trip coil TC11 is excited, and the main circuit is shut off.

[0003]

However, in the circuit breaker 11, the test circuit 13 cannot be established unless the connection to the neutral line N is cut off by the changeover switch SW11, so that the structure of the circuit breaker 11 becomes complicated. However, there is a disadvantage that the manufacturing cost is increased.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the conventional circuit breaker, an object of the present invention is to provide an extremely simple structure,
Further, the present invention provides a single-phase three-wire circuit breaker without increasing the manufacturing cost, and has a structure including an abnormal voltage detection circuit for detecting application of an abnormal voltage to the single-phase three-wire circuit. A trip coil excited by the output of the abnormal voltage detection circuit, a tripping mechanism for shutting off a main circuit operated by the excitation of the trip coil, and a test for confirming operation of a neutral line open phase protection function. Circuit, the voltage of the main circuit is divided by a voltage dividing circuit and applied to the abnormal voltage detecting circuit, and when a voltage corresponding to a preset trip voltage is applied. The main circuit is cut off, and the test circuit is composed of a test switch and a constant voltage circuit. When the test switch is turned on, the constant voltage circuit corresponds to a trip voltage of the abnormal voltage detection circuit. Applying a pressure, and to shut off the main circuit.

In the single-phase three-wire circuit breaker, a diode is connected between the voltage dividing circuit and the test circuit, and an abnormal voltage detecting circuit includes a voltage applied to the voltage dividing circuit; The larger of the voltages applied to the test circuit is applied.

[0006]

[Function] When an abnormal voltage is applied to the main circuit, the voltage across the resistor of the voltage dividing circuit exceeds the trip voltage, and this voltage is applied to the abnormal voltage input terminal of the overvoltage detection circuit. Activate the trip mechanism to shut off the main circuit. When the test switch of the test circuit is turned on, a voltage corresponding to a trip voltage is applied to the abnormal voltage input terminal of the overvoltage detection circuit via the diode by a constant voltage circuit including a resistor and a constant voltage diode connected to the test switch. The tripping mechanism is activated by the excitation of the trip coil and the main circuit is cut off.

[0007]

FIG. 1 shows a first embodiment of a single-phase three-wire circuit breaker according to the present invention. Hereinafter, description will be given based on this drawing.

The single-phase three-wire circuit breaker 1 includes an abnormal voltage detecting circuit IC1 for detecting the application of an abnormal voltage, a trip coil TC1 excited by an output of the abnormal voltage detecting circuit IC1, and a trip coil TC1. It is provided with a tripping mechanism 2 for shutting off a main circuit operated by the excitation of the TC 1 and a test circuit 3 for confirming the operation of the neutral line open phase protection function. The voltage of the main circuit is divided by a voltage dividing circuit 4 composed of resistors R1 and R2 and applied to an abnormal voltage detecting circuit IC1. The test circuit 3 includes a test switch TS and a constant voltage circuit 5, and when the test switch TS is turned on, the constant voltage circuit 5 applies a voltage corresponding to a trip voltage to the abnormal voltage detection circuit IC1.

When an abnormal voltage is applied to the main circuit, the voltage across the resistors R1 and R2 of the voltage dividing circuit 4 exceeds the trip voltage, and this voltage is applied to the abnormal voltage input terminal of the overvoltage detection circuit IC1. The trip mechanism 2 is operated by exciting the trip coil TC1, and the main circuit is shut off. When the test switch TS of the test circuit 3 is turned on, the overvoltage detection circuit IC is activated by the constant voltage circuit 5 including the resistor R3 and the constant voltage diode ZD connected to the test switch TS.
1, a voltage corresponding to the trip voltage is applied to the abnormal voltage input terminal via the diode D1, and the trip coil TC
The tripping mechanism 2 is actuated by the excitation of 1 to cut off the main circuit.

The second aspect of the single-phase three-wire circuit breaker according to the present invention
An example is shown in FIG. Hereinafter, description will be given based on this drawing.

The single-phase three-wire circuit breaker 1 includes an abnormal voltage detecting circuit IC1 for detecting the application of an abnormal voltage, a trip coil TC1 excited by an output of the abnormal voltage detecting circuit IC1, and a trip coil TC1. It is provided with a tripping mechanism 2 for shutting off a main circuit operated by the excitation of the TC 1 and a test circuit 3 for confirming the operation of the neutral line open phase protection function. The voltage of the main circuit is divided by a voltage dividing circuit 4 composed of resistors R1 and R2 and applied to an abnormal voltage detecting circuit IC1. The test circuit 3 includes a test switch TS and a constant voltage circuit 5, and when the test switch TS is turned on, the constant voltage circuit 5 applies a voltage corresponding to a trip voltage to the abnormal voltage detection circuit IC1. A diode D2 is connected between the voltage dividing circuit 4 and the test circuit 3.

When an abnormal voltage is applied to the main circuit, the voltage across the resistors R1 and R2 of the voltage dividing circuit 4 is changed to a diode D2.
This voltage is applied to the abnormal voltage input terminal of the overvoltage detection circuit IC1, and the trip mechanism 2 is operated by exciting the trip coil TC1 to shut off the main circuit. Further, when the test switch TS of the test circuit 3 is turned on, the constant voltage circuit 5 including the resistor R3 and the constant voltage diode ZD connected to the test switch TS causes the abnormal voltage input terminal of the overvoltage detection circuit IC1 to correspond to the trip voltage. Is applied through the diode D1, and the tripping mechanism 2 is operated by the excitation of the trip coil TC1 to cut off the main circuit. The larger of the voltage applied to the voltage dividing circuit 4 and the voltage applied to the test circuit 3 is applied to the abnormal voltage detecting circuit IC1.

[0013]

As described above, the single-phase three-wire circuit breaker according to the present invention has an abnormal voltage detection circuit for detecting the application of an abnormal voltage to a single-phase three-wire circuit, and an abnormal voltage detection circuit. A trip coil excited by the output of the circuit, a trip mechanism for shutting off a main circuit operated by excitation of the trip coil, and a test circuit for confirming the operation of the neutral line open phase protection function are provided. In a single-phase three-wire circuit breaker, the voltage of the main circuit is divided by a voltage divider circuit and applied to the abnormal voltage detection circuit. When a voltage corresponding to a preset trip voltage is applied, the main circuit is shut off. In addition, the test circuit includes a test switch and a constant voltage circuit. When the test switch is turned on, the constant voltage circuit applies a voltage corresponding to a trip voltage to the abnormal voltage detection circuit. Interception By so in a very simple structure of only the test switch and the electronic component can form the test circuit, with no increasing manufacturing costs, there is an effect that the workability, processability is improved.

In the single-phase three-wire circuit breaker, a diode is connected between the voltage dividing circuit and the test circuit, and a voltage applied to the voltage dividing circuit is supplied to the abnormal voltage detecting circuit. By applying the higher voltage out of the voltages applied to the test circuit, the other circuit is not affected by the voltage dividing circuit or the test circuit, and the reliability is improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a first embodiment of a single-phase three-wire circuit breaker according to the present invention.

FIG. 2 is a circuit diagram of a second embodiment of the single-phase three-wire circuit breaker according to the present invention.

FIG. 3 is a circuit diagram of a conventional single-phase three-wire circuit breaker.

[Explanation of symbols]

1 ... single-phase three-wire circuit breaker 2 ... tripping mechanism,
3 ... test circuit, 4 ... voltage divider circuit, 5 ... constant voltage circuit, IC1 ... abnormal voltage detection circuit, TC1 ...
Trip coil, TS: Test switch, R1, R
2, R3, R4: resistor, D1, D2: diode.

Claims (2)

(57) [Claims] 1. An abnormal voltage detecting circuit for detecting application of an abnormal voltage to a single-phase three-wire circuit, a trip coil excited by an output of the abnormal voltage detecting circuit, and an operation by exciting the trip coil. A single-phase three-wire circuit breaker provided with a tripping mechanism for interrupting a main circuit to perform, and a test circuit for confirming operation of a neutral-phase-loss protection function,
The voltage of the main circuit is divided by a voltage divider circuit and applied to the abnormal voltage detection circuit.When a voltage corresponding to a preset trip voltage is applied, the main circuit is shut off, and the test circuit includes a test switch. And a constant voltage circuit, wherein the constant voltage circuit applies a voltage corresponding to a trip voltage to the abnormal voltage detection circuit when the test switch is turned on, and shuts off a main circuit. Wire circuit breaker. 2. In the single-phase three-wire circuit breaker, a diode is connected between the voltage dividing circuit and the test circuit, and a voltage applied to the voltage dividing circuit is provided to an abnormal voltage detecting circuit. A single-phase three-wire circuit breaker, wherein the larger of the voltages applied to the test circuit is applied.