JPH0568055U - Earth leakage circuit breaker with AA neutral line open phase protection - Google Patents

Abstract

(57) [Summary] [Object] To provide an earth leakage breaker capable of confirming the operations of both the earth leakage detection circuit and the abnormal voltage detection circuit with a single test button. [Structure] One test button TS is connected to the pseudo leakage circuit 11
And the pseudo open phase circuit 13 are shared, and when confirming the operation of the leakage detection circuit composed of the zero-phase current transformer ZCT, etc., the terminal 12 of the detection line is connected to the neutral line N on the load side. When the test button TS is pressed while the terminal 7 is still connected, the controller 9 opens the main circuit contact 8 via the magnet coil MC. Moreover, when confirming the operation of the abnormal voltage detection circuit composed of the test resistance RT etc., the terminal 1 of the detection line is used.
When 2 is removed from the load side terminal 7 of the neutral wire N and the same test button TS as described above is pressed, the controller 9 opens the main circuit contact 8 via the magnet coil MC.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an earth leakage circuit breaker with open-phase protection used for a single-phase three-wire electric line, and in particular, it is possible to confirm the operation of both the earth leakage detection circuit and the abnormal voltage detection circuit with one test button. It is related to a simple earth leakage breaker.

[0002]

[Prior Art]

 Conventionally, various kinds of AA neutral line breaker protection earth leakage circuit breakers having this type of test button have been proposed, and such circuit breakers are generally known as a leakage detection circuit, an abnormal voltage detection circuit and a test circuit. It has a button circuit for use.

The earth leakage detection circuit uses a single-phase three-wire type electric wire line consisting of two voltage lines and one neutral line as a primary coil, and a sensor for extracting a ground fault zero-phase current as an abnormal current signal. When leakage is detected through the output from the zero-phase current transformer ZCT, which is the next coil, the switch circuit excites the coil to open the main circuit contact.

Further, the abnormal voltage detection circuit takes out line voltages of two voltage lines and one neutral line respectively, and detects the imbalance in the line voltage due to the open phase of the neutral line. By detecting as an abnormal signal, the coil is excited and energized via the switch circuit to open the main contact circuit.

Further, the test button circuit includes a pseudo resistance composed of a test resistor and a contact of a test button between a pair of voltage lines or between one of the pair of voltage lines and a neutral line. It forms a leakage circuit and generates a current detected by the zero-phase current transformer ZCT when the test button is pressed. The current thus generated is detected as an abnormal current by the leakage detection circuit, so that the main contact circuit is opened in the same manner as described above.

As described above, the test button provided in the conventional leakage breaker with an AA neutral line open-phase protection is for confirming whether or not the leakage detection circuit operates normally. It was

[0007]

[Problems to be solved by the device]

 However, the test button in the conventional earth leakage breaker with AA neutral line protection is provided to confirm the operation of the earth leakage detection circuit. It was not possible to confirm whether the abnormal voltage detection circuit operates normally.

When the operation confirmation of the abnormal voltage detection circuit is intentionally performed by the test button for confirming the operation of the leakage detection circuit, the detection wire connected to the neutral wire terminal is removed from the terminal, and the two wires are removed. It is necessary to touch one side of the electric line for about 0.5 seconds. This method is extremely dangerous work for workers, and no such confirmation method is usually performed.

Even if the normal operation of the abnormal voltage detection circuit is confirmed by such a confirmation method, the confirmation is made between one of the electric lines and the neutral line or between the other of the electric lines and the neutral line. It was performed by applying 200 V in the meanwhile, and therefore it could not be confirmed that the operation was performed at the set voltage, which was almost meaningless.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and provides a test button that can be shared when confirming the operations of both the leakage detection circuit and the abnormal voltage detection circuit, and The purpose of the present invention is to provide an earth leakage circuit breaker with AA neutral line open-phase protection that allows the operation of both circuits to be checked easily and safely by making it possible to check the operation of both circuits with a button. And

[0011]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is used in a single-phase three-wire type distribution line composed of two voltage lines and one neutral line having an external connection line, and is also used for a leakage detection circuit and an abnormal voltage detection circuit. The operation of each of the above circuits is confirmed in an AA earth leakage circuit breaker with open-circuit protection that opens the main circuit contact by energizing the coil based on the detection signal from each circuit. In addition, a test button that is commonly used when checking the operation of each circuit is provided.

[0012]

[Action]

 In the present invention having the above structure, when the operation of the leakage detection circuit is confirmed, the test button is pressed while the external connection line is connected to the load side terminal of the neutral line. A pseudo leakage circuit is formed by pressing the test button, and the generated current is detected via the leakage detection circuit. Based on the detection signal from this leakage detection circuit, the coil is excited and energized to open the main contact circuit.

Further, when confirming the operation of the abnormal voltage detection circuit, the external connection line is removed from the load side terminal of the neutral line and the test button is pressed. A pseudo open phase circuit is formed by pressing the test button, and the abnormal voltage generated is detected by the abnormal voltage detection circuit. Based on the detection signal from this abnormal voltage detection circuit, the coil is excited and energized to open the main contact circuit.

[0014]

【Example】

 Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 shows a control circuit diagram of an earth leakage breaker with AA neutral line open-phase protection.

In the figure, an AA neutral line open-circuit protection earth leakage circuit breaker is used by being connected to a main circuit 1 composed of a single-phase three-wire type electric line. The main circuit 1 is composed of two voltage lines L1 and L2 and one neutral line N. The upper side in FIG. 1 is the power supply side terminals 2, 3 and 4, and the lower side in FIG. These are load side terminals 5, 6, and 7.

In the middle of each of the voltage lines L1, L2 and the neutral line N, three poles are simultaneously interlocked with each other so that they can be opened / closed by a manual operation, and an electromagnetic force is generated by exciting a magnet coil MC described later. A main circuit contact 8 that can be opened and closed with force is provided.

On the downstream side of the main circuit contact 8, the zero-phase current transformer ZCT is inserted through the voltage lines L 1 and L 2, the neutral line N of the main circuit 1 and the line 15 of the pseudo leakage circuit 11 described later. It is provided to do so. In the zero-phase current transformer ZCT, the voltage lines L1, L2, the neutral line N, and the line 15 of the pseudo leakage circuit 11 are used as primary coils, and the sensor of the leakage current is used as a secondary coil, and each voltage line L1 is used. , L2 and the like, when a leakage current occurs, a predetermined voltage is induced and output to the input ports A and B of the control device 9. The zero-phase current transformer ZCT, the controller 9 and the like constitute a leakage current detection circuit.

A magnet coil MC is connected on a line l1 branched from the voltage line L1, and a thyristor 10 is connected between the line l1 and a line l2 branched from the voltage line L2. .. The control electrode of this thyristor 10 is connected to the output port C of the control device 9 via the line l3.

Accordingly, the control device 9 switches from the output port C to the control electrode of the thyristor 10 via the line 13 when the predetermined voltage generated by the zero-phase current transformer ZCT is input to the input ports A and B. A signal is sent to fire the thyristor 10 to energize the magnet coil MC from the voltage line L1 through the line l1. The main circuit contacts 8 in the closed state are interlocked with each other and opened by the excitation of the magnet coil MC.

Next, the pseudo leakage circuit 11 will be described. The pseudo earth leakage circuit 11 is connected to the line 12 from the voltage line L 2, the test button TS inserted on the line 14 branched from the line 12 and the test resistor RT, and the line 17 and the line 17 branched from the line l4. Then, the line l5 wound around the zero-phase current transformer ZCT n times (the line l5 penetrates the zero-phase current transformer ZCT n times) and the terminal 12 of the detection line provided at the end of the line l5. It is composed of a circuit that reaches the load side terminal 7 of the connected neutral wire N. The terminal 12 of the detection line is normally connected to the load side terminal 7 of the neutral line N.

Here, the pseudo leakage current value flowing through the pseudo leakage circuit 11 is set based on the test resistance RT according to the following equation 1.

[Equation 1]

Here, in the equation 1, n represents the number of times the line 15 passes through the zero-phase current transformer ZCT as described above.

Next, the pseudo open phase circuit 13 will be described. When forming the pseudo open phase circuit 13, the terminal 12 of the detection line is removed from the load side terminal 7 of the neutral line N.

Accordingly, the pseudo phase open circuit 13 includes a diode 14 branched from the voltage line L2 to the line 12, the line 14, the test button TS, the test resistor RT, the resistor R1, the resistor R2 on the line 18, and the line 12. , A circuit extending to the voltage line L1 via the magnet coil MC, and 200 V is applied to the pseudo open phase circuit 13.

In the pseudo phase open circuit 13, the voltage across the resistance-divided resistor R2 is input to the input ports D and E of the controller 9 via the lines 18 and 19. As a result, the control device 9 monitors the terminal voltage of the resistor R2 via the input ports D and E. An abnormal voltage generated between the input ports D and E during the monitoring is detected by the control device 9 as an abnormal voltage detection device via the resistors RT, R1 and R2 which constitute the abnormal voltage detection circuit. It is a thing.

Here, the resistance value of each of the resistors RT, R1 and R2 is set to a predetermined set operating voltage between the voltage line L1 and the neutral line N or between the voltage line L2 and the neutral line N. Is set to be applied to the input ports D and E of the control device 9 in the same manner as when the voltage is applied.

The resistance values of the resistors RT, R1 and R2 are set so as to satisfy the following expression 2.

[Equation 2]

In the equation 2, RIC represents an internal resistance between the output ports D and E in the control device 9. Further, since the internal resistance of the magnet coil MC is sufficiently small so as to be negligible as compared with the test resistance RT, the resistance R1, the resistance R2, and the resistance RIC, they are neglected in the equation (2).

Next, the operation of each circuit configured as described above will be described.

First, the operation of the pseudo leak circuit 11 will be described. In this case, the test button TS is pressed while the terminal 12 of the detection line is connected to the load side terminal 7 of the neutral line N. When the test button TS is pressed in this way, a pseudo-leakage current flows from the voltage line L2 to the load side terminal 7 of the neutral line N along the pseudo-leakage circuit 11, so that the zero-phase current transformer ZCT is predetermined. Is generated and the control circuit 9 detects it via the input ports A and B. Then, the control device 9 outputs a switching signal from the output port C to the control electrode of the thyristor 10 via the line 13 to ignite the thyristor 10 and energizes the magnet coil MC as described above to excite the main circuit. The contact 8 is opened.

Next, when confirming the operation of the pseudo open phase circuit 13, the terminal 12 of the detection line is removed from the load side terminal 7 of the neutral line N, and then the test button TS is pressed. As described above, when the test button TS is pressed, a voltage of 200V is applied between the voltage line L1 and the voltage line L2 in the pseudo open phase circuit 13, and the pseudo voltage is applied to the neutral line N. A missing phase is formed at. The occurrence of such a phase loss is detected by the voltage appearing between the input ports D 1 and E 2 of the control device 9.

At this time, the resistance value of each of the resistors RT, R1, and R2 is set to a predetermined operating voltage between the voltage line L1 and the neutral line N or between the voltage line L2 and the neutral line N. Since the same voltage as when the voltage is applied is set to be applied to the input ports D and E of the control device 9, the control device 9 judges that the phase loss has occurred in the neutral line N. Then, based on such a determination, a switch signal is output from the output port C to the control electrode of the thyristor 10 via the line l3. As a result, the thyristor 10 is fired and the magnet coil MC is energized and energized from the voltage line L1 through the line 11, and as a result, the main circuit contact 8 is opened.

As described above in detail, according to the AA neutral line open-phase protective earth leakage circuit breaker according to this embodiment, one test button TS is connected to the pseudo earth leakage circuit 11 and the pseudo open phase circuit 13. Since it is arranged to be shared by both sides, when confirming the operation of the leakage detection circuit composed of the zero-phase current transformer ZCT, etc., the terminal 12A of the detection line 12 is connected to the load side terminal 7 of the neutral line N. If the test button TS is pressed while being connected, the controller 9 can open the main circuit contact 8 through the magnet coil MC, and the abnormality caused by the resistors RT, R1, R2, etc. and the controller 9 will occur. When confirming the operation of the voltage detection circuit, if the terminal 12A of the detection line 12 is removed from the load side terminal 7 of the neutral line N and the same test button TS as described above is pressed, the control device 9 causes the magnet coil MC to operate. Open the main circuit contact 8 via Can be made.

In this way, by forming the pseudo leakage circuit 11 and the pseudo open phase circuit 13 via one test button TS, it is easy to confirm the operations of both the leakage detection circuit and the abnormal voltage detection circuit. In addition, such confirmation work can be performed extremely safely, unlike the conventional earth leakage circuit breaker with AA neutral line open circuit protection.

Further, in the present embodiment, as described above, the resistance value of each of the resistors RT, R1 and R2 is between the voltage line L1 and the neutral line N or between the voltage line L2 and the neutral line N. Since a voltage similar to that when a predetermined set operating voltage is applied is set so as to be applied to the input ports D and E of the control device 9, the pseudo-missing voltage is applied while the predetermined set voltage is applied. The operation of the abnormal voltage detection circuit can be confirmed through the phase circuit 13, which is highly useful.

Further, the leakage current detection circuit and the abnormal voltage detection circuit have different operation times. For example, the operation time of the leakage detection circuit is within 0.1 seconds, and the operation time of the abnormal voltage detection circuit is Within 0.5 seconds. Therefore, when the detection wire connected to the load side terminal 7 of the neutral wire N is broken, the operation time of the circuit becomes long due to the open phase. By pressing the button, it is possible to know the disconnection of the detection line.

In the above embodiment, the pseudo leakage circuit 11 and the pseudo open phase circuit 13 are formed via one test button TS, so that both the leakage detection circuit and the abnormal voltage detection circuit are formed. Although the operation check can be performed, as shown in FIG. 2, the pseudo leakage circuit 11 is provided with the leakage detection test button Ts1 and the pseudo open phase circuit 13 is provided with the open phase detection test button Ts2. Even in this case, the same operation as in the above embodiment can be performed.

That is, in FIG. 2 (the main parts in the precursor embodiment shown in FIG. 1 are described with the same reference numerals), first, the pseudo leakage circuit 11 formed via the leakage detection test button Ts1. Will be described.

When the earth leakage detection test button Ts1 is pressed, a pseudo earth leakage circuit 11 extending from the voltage line L1 to the voltage line L2 via the test resistor RT1, the earth leakage detection test button Ts1, and the zero-phase current transformer ZCT is formed. As a result, a predetermined voltage is induced in the zero-phase current transformer ZCT in the same manner as in the above embodiment, and this voltage is detected by the input ports A and B of the control device 9. Based on this detection, the control device 9 outputs a switching signal from the output port C to turn on the thyristor 10.

When the thyristor 10 is thus fired, an exciting current flows from the voltage line L1 to the magnet coil MC via the test resistor RT1, so that the magnet coil MC is energized and the main circuit contact 8 is opened. is there.

Next, the pseudo open phase circuit 13 formed via the open phase detection test button TS2 will be described. The open-phase detection test button TS2 is composed of a three-pole double-throw momentary switch and is connected as shown in FIG. 2 in a normal state.

When the open phase detection test button TS2 is pressed, the open phase detection test button TS2 is switched to the state shown by the broken line in FIG. That is, the open-phase detection test button TS2 is connected to the contact S1 on one side of the test resistor RTS and the contact S3 on one side of the test resistor RT3, and is also connected to the contact S2 between the test resistors RT2 and RT3. It is disconnected from the load side terminal 7 of N.

In this state, a voltage of 200 V is applied between the contacts S1 and S3, and a voltage obtained by dividing 200 V by the resistance ratio of the test resistors RT2 and RT3 is applied to the contact S2. There is. Here, the resistance value of each test resistor RT2, RT3 is determined so that a predetermined set voltage is applied to the contact S2 to operate the earth leakage breaker.

When an abnormal voltage is generated across the test resistor RT2, the pseudo open phase circuit 13 is a circuit from the contact S2 to the contact S1 via the resistance R1, the resistance R2, the diode 14 and the magnet coil MC. Once formed, controller 9 detects the voltage across resistor R2 by monitoring input ports D and E.

When the control device 9 detects the occurrence of the abnormal voltage via the input ports D and E, the switching signal is output from the output port C in the same manner as described above to turn on the thyristor 10 and excite the magnet coil MC. The main contact circuit 8 is opened by energizing.

When an abnormal voltage is generated across the test resistor RT3, the pseudo open-phase circuit 13 is formed by a circuit from the contact S2 to the contact R3 via the resistor R1, the resistor R2 and the diode 15, and the control device 9 Monitors the input ports D and E as described above and detects the voltage across the resistor R2.

When the control device 9 detects an abnormal voltage via the input ports D and E, the main contact circuit 8 is opened by exciting the magnet coil MC in the same manner as described above.

[0048]

[Effect of the device]

 As described above, the present invention provides a test button that can be shared when confirming the operation of both the leakage detection circuit and the abnormal voltage detection circuit, and the operation of both circuits can be confirmed by such a test button. In addition, it is possible to provide a leakage breaker with AA neutral line open-phase protection that can easily check the operation of both circuits, and its industrial effect is great.

[Brief description of drawings]

FIG. 1 is a control circuit diagram of an earth leakage breaker with AA neutral line open-phase protection.

FIG. 2 is a control circuit diagram of a leakage breaker with AA neutral line open-phase protection in which test buttons are provided on both the pseudo-earthleakage circuit and the pseudo-open-phase circuit.

[Explanation of symbols]

1 main circuit 2, 3, 4 power supply side terminal 5, 6, 7 load side terminal 8 main circuit contact 9 control device 11 pseudo leakage circuit 12 detection line terminal 13 pseudo open phase circuit L1, L2 voltage line N neutral line MC Magnet coil ZCT Zero-phase current transformer A, B, C, D, E Control device input / output port TS Test button

Claims (1)

[Scope of utility model registration request] 1. A single-phase three-wire type power distribution line comprising two voltage lines and one neutral line having an external connection line, and having a leakage detection circuit and an abnormal voltage detection circuit,
In an earth leakage breaker with AA neutral line open-phase protection, which opens the main circuit contact by energizing the coil based on the detection signal from each circuit, confirms the operation of each circuit and operates each circuit. A leakage breaker with AA neutral line open-phase protection, which is equipped with a test button that is commonly used for confirmation.