JPH0621142U - Earth leakage circuit breaker - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an earth leakage circuit breaker having the same electronic control unit in a single-phase three-wire system and a three-phase three-wire system. A power supply line 5, 5 is provided between the electronic control unit 4 and the R-phase electric line and the T-phase electric line, and an open-phase detection line 6 is provided between the electronic control unit 4 and the S-phase electric line. A relay contact 7 is provided in the middle of the circuit, a voltage detection circuit 8 for detecting the interphase voltage of the electric path in the electronic control unit 4, a voltage comparison circuit 9 for comparing the interphase voltage, and a judgment circuit 10 for judging the type of the electric path.
And a relay drive circuit 11 for driving the relay contact 7 from the determination circuit 10.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an earth leakage breaker used for single-phase three-wire type and three-phase three-wire type electric circuits.

[0002]

[Prior art]

 Prior art leakage breakers are shown in Fig. 3 for a single-phase three-wire system and for a three-phase three-wire system, which correspond to the leakage current from the circuit. A zero-phase current transformer 21 that outputs a leakage current detection signal and a leakage current detection signal from the zero-phase current transformer 21 are detected, a current is passed through a trip coil 22, a contact 23 is opened, and a circuit is opened. It was equipped with an electronic control unit 24 for shutting off.

In the single-phase, three-wire type earth leakage circuit breaker of FIG. 3, a power supply line 25 is provided between the electronic control unit 24 inside the earth leakage circuit breaker and the R-phase electric circuit and the T-phase electric circuit, and the electronic control unit 24 An open-phase detection line 26 is provided between the S-phase and S-phase electric circuit. In the earth leakage circuit breaker dedicated to the three-phase three-wire system shown in FIG. 4, only two power supply lines 25 are provided from the electronic control unit 24 inside the earth leakage circuit breaker. Was provided, and the earth leakage breakers provided with the electronic control unit 24 corresponding to each electric circuit were prepared.

[Problems to be solved by the device]

 However, according to the above-mentioned conventional earth leakage breaker, since the earth leakage breaker corresponding to the single-phase three-wire type or the three-phase three-wire type electric circuit has the electronic control unit corresponding to each electric circuit, Even if they have the same shape, the circuits of the electronic control unit are different, resulting in excessive manufacturing costs and very difficult inventory management.

Therefore, the present invention is to provide an earth leakage breaker having the same electronic control unit in a single-phase three-wire type and a three-phase three-wire type electric circuit.

[0005]

In order to solve the above problems, an earth leakage circuit breaker according to the present invention includes a power supply line between an electronic control unit and an R-phase circuit and a T-phase circuit, and an electronic control unit. The open-phase detection line is provided between the S-phase electric lines, the relay contact is provided in the middle of the open-phase detection line, and a voltage detection circuit that detects the inter-phase voltage of the electric line in the electronic control unit and a voltage comparison that compares the inter-phase voltage The circuit includes a circuit, a discriminating circuit for discriminating the type of electric circuit, and a relay drive circuit for driving a relay contact from the discriminating circuit.

[0006]

[Action]

 When the earth leakage breaker is installed in the single-phase three-wire type or three-phase three-wire type electric circuit and voltage is applied, the voltage detection circuit detects the interphase voltage, the voltage comparison circuit compares the voltages, and the discrimination circuit detects the single-phase three The type of wire or three-phase three-wire circuit is determined, and if it is a single-phase three-wire system, the relay drive circuit closes the relay contact in the middle of the open phase detection line, and the three-phase three-wire system. If it is a formula, the relay contact is opened. Therefore, the same earth leakage circuit breaker may be installed in the electric circuit without selecting the earth leakage circuit breaker according to the single-phase three-wire type and the three-phase three-wire type electric circuit.

[0007]

【Example】

 An embodiment of an earth leakage breaker according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an explanatory view of an earth leakage breaker according to the present invention, which shows a zero-phase current transformer 1 which outputs a leakage current detection signal corresponding to a leakage current from an electric line, and the zero-phase current transformer 1 Leakage current detection signal of the single-phase three-wire system and three-phase system equipped with an electronic control unit 4 that opens the contact 3 by energizing the trip coil 2 and actuates the trip body to cut off the electric path. In the phase 3 wire type earth leakage circuit breaker, one power supply line 5 and 5 is provided between the electronic control unit 4 and the R-phase electric circuit and the T-phase electric circuit, and an abnormal voltage is detected between the electronic control unit 4 and the S-phase electric circuit. Of the open phase detection line 6, the relay contact 7 is provided in the middle of the open phase detection line 6, and the electronic control unit 4 detects the interphase voltage (V _RS , V _ST , V _RT ) of the circuit. A circuit 8, a voltage comparison circuit 9 that compares the interphase voltage, and a determination circuit 1 that determines the type of the electric circuit 0, and a relay drive circuit 11 for driving the relay contact 7 from the determination circuit 10 thereof.

The voltage comparison circuit 9 reads the voltage value of the interphase voltage (V _RS , V _ST , V _RT ) of the electric path detected by the voltage detection circuit 8, and the voltage value is sent to the determination circuit 10.

In the discrimination circuit 10, the voltage value of the interphase voltage (V _RS , V _ST , V _RT ) sent from the voltage comparison circuit 9 is expressed as V _RS + V _ST = V _RT = single-phase three-wire type electric circuit, V _RS = _VST = _VRT = Three-phase three-wire type electric line is discriminated, and the electric line discrimination signal is sent to the relay drive circuit 11.

Therefore, in the earth leakage circuit breaker configured as described above, the electronic control unit provided inside the earth leakage circuit breaker of the single-phase three-wire type and the three-phase three-wire type electric circuit can be shared, and two types are available. Since only one type of circuit breaker can be used, the manufacturing cost of the electronic control unit will be low, and inventory control will be extremely easy.

FIG. 2 is an explanatory view of a modified embodiment of the earth leakage circuit breaker according to the present invention, in which the open-phase detection line 6 provided in the electronic control unit 4 is not the S-phase electric circuit 12 inside the earth leakage circuit breaker. The open phase detection wire 6 is output to the outside of the earth leakage breaker via a relay contact 7 provided in the middle of the wire 6. The end of the open phase detection wire 6 is connected to the load side S-phase electric circuit 12a outside the earth leakage breaker. Since they are connected, an abnormal voltage between the electric circuits from the outside of the earth leakage breaker to the connection of the open-phase detection line 6 can be additionally detected, and the safety is enhanced when the earth leakage breaker is used.

In the above embodiment, the relay contact 7 provided in the middle of the open phase detection line 6 uses the a contact, but this is an example, and the relay contact 7 is limited to the a contact. It is also possible to use a b-contact relay instead of the one.

[0014]

[Effect of device]

 As described above, the earth leakage circuit breaker according to the present invention includes the power supply line between the electronic control unit and the R-phase electric circuit and the T-phase electric circuit, and the open-phase detection line between the electronic control unit and the S-phase electric circuit. , A relay contact in the middle of the open phase detection line, a voltage detection circuit that detects the interphase voltage of the electric path in the electronic control unit, a voltage comparison circuit that compares the interphase voltage, and a judgment circuit that determines the type of the electric path. And a relay drive circuit that drives the relay contacts from the determination circuit, the electronic control unit provided inside the earth leakage breaker of the single-phase three-wire type and the three-phase three-wire type electric circuit can be shared. Since the earth leakage circuit breaker, which was available in two types, can be handled by one type, it has an excellent effect such that the manufacturing cost of the electronic control unit is low and inventory management is also very easy. .

[Brief description of drawings]

FIG. 1 is an explanatory view of an earth leakage breaker according to the present invention.

FIG. 2 is an explanatory view of a modified embodiment of the earth leakage circuit breaker according to the present invention.

FIG. 3 is an explanatory diagram of a conventional earth leakage breaker.

FIG. 4 is an explanatory diagram of a conventional earth leakage breaker.

[Explanation of symbols]

1 ... Zero-phase current transformer, 2 ... Tripping coil, 3 ...
・ Contact points, 4 ・ ・ ・ Electronic control part, 5 ・ ・ ・ Power line, 6 ・ ・
・ Open phase detection line, 7 ... Relay contact, 8 ... Voltage detection circuit, 9 ... Voltage comparison circuit, 10 ... Discrimination circuit, 1
1 ... Relay drive circuit, 12, 12a ... S-phase electric circuit.

Claims (1)

[Scope of utility model registration request] 1. A zero-phase current transformer that outputs a leakage current detection signal corresponding to a leakage current from an electric circuit, and a leakage current detection signal from the zero-phase current transformer is detected to excite a trip coil. In a single-phase three-wire type and three-phase three-wire type earth leakage breaker, which comprises an electronic control unit that opens a contact by operating a tripping body to cut off the electric circuit, the electronic control unit and the R-phase electric circuit, A power line is provided between the T-phase electric lines, an open-phase detection line is provided between the electronic control unit and the S-phase electric line, a relay contact is provided in the middle of the open-phase detection line, and the phase between the electric lines is provided in the electronic control unit. A voltage detection circuit for detecting a voltage, a voltage comparison circuit for comparing the interphase voltage, a determination circuit for determining the type of the electric path, and a relay drive circuit for driving the relay contact from the determination circuit. Characteristic earth leakage breaker.