JP2010211948A - Earth leakage breaker with protection against neutral line open-phase for single-phase three lines - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an earth leakage breaker with protection against neutral line open-phase for single-phase three lines, having delay-time characteristics with regard to leak detection without complicating a circuit even if a conventional abnormal voltage determining IC circuit is used. <P>SOLUTION: An abnormal voltage determining circuit 6 made into an IC while including a leak detection circuit 6a, a thyristor driving signal generating circuit 6b and a phase interruption detection circuit 6c is used, and a No.6 terminal to remove noise of the leak detection circuit output 6a is connected to a No.10 terminal for time setting of the phase interruption circuit 6c through a diode D4, and is connected to a ground line 8 together with the No.10 terminal through a capacitor C5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an AA neutral circuit leakage protective circuit breaker having a function of interrupting a circuit when a neutral phase of a single-phase three-wire circuit is lost.

In recent years, with the widespread use of single-phase three-wire distribution lines, earth leakage circuit breakers with an AA-neutral wire phase loss protection function that protects load equipment from abnormal voltages that occur when the neutral wire phase is lost It is popular. Such a conventional AA neutral wire leakage circuit breaker with phase loss protection has a circuit configuration as shown in FIG. 2, for example.
In FIG. 2, the voltage between the voltage lines X and Y and the neutral line N is rectified by the diodes D1 and D2, divided by the two resistors R3 and R7, and the voltage applied to the resistor R7 is integrated into an IC. Monitoring is performed between terminals 1-11 of the voltage determination circuit 6. When a phase failure of the neutral line N occurs and an overvoltage is applied between the voltage line X and the neutral line N or between the voltage line Y and the neutral line N, the voltage applied to both ends of the resistor R7 increases. When a certain level is exceeded, a signal for turning on the thyristor Z1 is output from the eighth terminal of the abnormal voltage determination circuit 6, and the trip coil 2 is excited to perform the tripping operation of the contact 3 provided on the electric circuit.

JP 2001-177982 A

The above-described conventional AA neutral wire leakage circuit breaker with phase loss protection has successfully detected the phase loss and leakage of the neutral wire N of the circuit and has performed a circuit break operation. However, if a similar circuit breaker is provided in the branch circuit on the load side of this circuit breaker, and the main circuit breaker, the structure of the branch circuit breaker is adopted, for the leakage generated in each branch part, It is desirable to operate the branch circuit breaker without operating the main circuit breaker, and to cut off the electric circuit. To that end, delay the operation of the main circuit breaker side (delay operation), It is necessary to perform protection coordination.
However, the leakage detection function of the abnormal voltage determination circuit 6 used in the conventional leakage breaker with AA neutral wire phase loss protection is a high-speed type, and is not a time delay type for leakage detection. Therefore, the conventional circuit breaker can be used as the branch circuit breaker, but the main circuit breaker that requires the time delay characteristic cannot use the conventional leakage detection circuit, that is, the conventional abnormal voltage determination circuit 6 cannot be used. In addition, a complicated circuit configuration in which a time-delay type circuit was separately incorporated was required.
Since this circuit configuration leads to an increase in cost and an increase in the size of the circuit breaker case, a conventional abnormal voltage determination circuit can be used, and a time-delayed circuit breaker that can cope with only a simple circuit change has been desired. .

  Therefore, in view of such problems, the present invention uses a conventional IC abnormal voltage determination circuit, and has a delay characteristic for leakage detection without complicating the circuit. The purpose is to provide an earth leakage circuit breaker with protective of open phase.

In order to solve the above-mentioned problem, the invention of claim 1 comprises a phase loss detection circuit, a leakage detection circuit, and a thyristor drive signal generation circuit. When a phase failure or leakage of a neutral wire is detected, a thyristor drive signal is detected. An abnormal voltage judgment circuit that has been integrated into an IC that outputs a signal is incorporated. In response to the occurrence of a neutral phase failure or leakage of a single-phase three-wire circuit, the contact on the circuit is opened by the thyristor drive signal. In the earth leakage circuit breaker with AA neutral line phase loss protection that operates to cut off, a specific terminal for noise removal of the leakage detection circuit output is connected to a diode at a specific terminal for time setting of the phase loss detection circuit. And a terminal for setting the time together with a ground line via a capacitor.
According to this configuration, since the circuit that sets the delay time for the phase loss detection is also operated for the leakage detection, the leakage detection operation can be delayed.

  According to the present invention, it is possible to provide a time delay characteristic for leakage detection with a simple circuit configuration using an abnormal voltage determination circuit that is made into an IC. Therefore, it is not necessary to incorporate a circuit for performing a time delay operation separately, and the protection cooperative operation can be performed at a low cost.

It is a circuit diagram which shows an example of the earth leakage breaker with an AA neutral line phase loss protection based on this invention. It is a circuit diagram of the conventional earth leakage circuit breaker with AA neutral wire phase loss protection.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. FIG. 1 is a circuit diagram showing an example of a leakage breaker with AA neutral line phase loss protection according to the present invention. From two voltage lines (X-phase voltage line and Y-phase voltage line) and neutral line N, FIG. A single-phase three-wire electric circuit 1 is provided with a contact 3 that opens when the trip coil 2 is operated, and a zero-phase current transformer 4 that detects a leakage, and a leakage and phase loss detection circuit 5 Configured to detect.
The earth leakage and phase loss detection circuit 5 has an abnormal voltage determination circuit 6 (integrated as an IC) formed of an integrated circuit, to which a zero-phase current transformer 4 is connected, an X-phase voltage line, and a Y-phase voltage. A voltage signal between the line and the neutral line N (hereinafter referred to as X-N and Y-N) is input.

  The abnormal voltage determination circuit 6 includes a leakage detection circuit 6a, a thyristor drive signal generation circuit 6b, a phase loss detection circuit 6c, and a power supply circuit 6d. A thyristor drive signal is output. Specifically, the semiconductor integrated circuit M54128FP manufactured by Renesas Technology Corp. is used.

  In addition, 10 is a power supply side terminal of the earth leakage circuit breaker with AA neutral wire phase loss protection, and 11 is a load side terminal. As shown in FIG. 1, the zero-phase current transformer 4 is connected to the 3-4 terminal which is the input terminal of the abnormal voltage determination circuit 6, and the phase loss detection line 7 connected to the neutral line N is a phase loss. It is connected to the eleventh terminal which is the input terminal of the detection circuit 6c. And the 6th terminal which is a terminal for noise removal of the abnormal voltage determination circuit 6 is connected to the 10th terminal which is the time delay setting terminal of the phase loss detection circuit 6c via the diode D4. The capacitor C5 is connected to the ground line 8. At this time, the diode D4 is in the forward direction toward the 10th terminal.

The AA circuit breaker with AA neutral wire phase loss protection configured as described above operates as follows. First, the case where a phase failure of the neutral line N occurs will be described. In the leakage and phase loss detection circuit 5, the voltages between X-N and Y-N are rectified by the diodes D1 and D2, and the rectified voltage is divided by the two resistors R3 and R7. No. 11 terminal is applied, and the determination operation is performed based on this voltage information.
When the phase loss of the neutral wire N occurs, the voltage applied to the 11th terminal rises and it is determined that the phase loss has occurred, and the thyristor drive voltage is output from the 8th terminal. Thus, the thyristor Z1 is turned on, the trip coil 2 is excited, the tripping operation of the contact 3 is performed, and the contact 3 is opened.

If a leakage occurs, it operates as follows. When a leakage occurs, the zero-phase current transformer 4 detects it and inputs it to the 3-4 terminal which is a leakage detection terminal of the abnormal voltage determination circuit 6. Then, the leakage detection circuit 6a performs the detection operation, and the thyristor drive voltage is output from the eighth terminal. Subsequent operations are the same as in the case of the above-mentioned phase failure.
However, it is not a form in which the 6th terminal is connected to the earth line through the capacitor which is the original connection form (the connection form shown in FIG. 2), but the leakage detection by connecting to the 10th terminal through the diode D4. The output of the circuit 6a is delayed by a time setting circuit that sets the delay time of the phase loss detection circuit 6c. As a result, the thyristor drive voltage signal output from the 10th terminal is output as a time-delayed signal, and it is possible to operate this AA neutral circuit leakage breaker with phase breaker protection as a main circuit breaker. Become.

  As described above, the leakage detection can be provided with a time delay characteristic with a simple circuit configuration using the abnormal voltage determination circuit 6 that is made into an IC. Therefore, it is not necessary to incorporate a circuit for performing a time delay operation separately, and the protection cooperative operation can be performed at a low cost. In addition, since the capacitor C3 shown in FIG. 2 is eliminated and only the diode D4 is added, the number of parts does not increase.

  1 .... Single-phase three-wire circuit, 2 .... Trip coil, 3 .... Contact, 4 .... Zero phase current transformer, 6 .... Abnormal voltage judgment circuit, Z1..Thyristor, D4..Diode.

Claims (1)

An abnormal voltage determination circuit that is integrated into an IC and outputs a thyristor drive signal when a phase failure or leakage of a neutral wire is detected, including a phase loss detection circuit, a leakage detection circuit, and a thyristor drive signal generation circuit, In response to the occurrence of a neutral phase failure or leakage in a single-phase three-wire circuit, an AGC neutral-phase leakage protection circuit breaker with an AA neutral wire failure phase protection that opens the contact on the circuit by the thyristor drive signal. In
A specific terminal for noise removal of the leakage detection circuit output is connected to a specific terminal for time setting of the phase loss detection circuit via a diode, and further, via a capacitor together with the terminal for time setting. A ground fault circuit breaker with AA neutral wire phase loss protection, which is connected to the ground line.

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