JPS6151491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a current leakage circuit and a circuit breaker that interrupts a circuit when a current leakage accident occurs in the circuit.

This type of earth leakage or disconnection circuit exists as shown in Figure 1.

That is, in FIG. 1, when a leakage occurs in the load L, it is detected by the zero-phase current transformer 1, a leakage output voltage appears in the secondary winding 4, and the leakage signal is sent to the amplifier 2, which is connected to semiconductor elements such as transistors and thyristors. Switching is performed by the device to operate the tripping electromagnet 5 and connect the electric circuit contact 6.
Open the circuit.

Conventional earth leakage and disconnection switches suddenly operate and open circuits when the operating earth leakage sensitivity current value is reached, so the state of the insulation resistance of the load L cannot be determined until after the circuit has been operated, which often causes inconvenience.

The present invention provides an advance warning to the user by lighting a light emitting diode in the event of an earth leakage or an earth leakage current that reaches the operating sensitivity current value of the circuit breaker, allowing the user to take necessary measures. This is the purpose.

The present invention will be explained below based on drawings showing an embodiment of the present invention. 1 is a zero-phase current transformer that detects an unbalanced current in a power line 3; 2 is a secondary output of a secondary winding 4 of the current transformer 1; A tripping electromagnet 5 is driven by an amplifier that increases the width of the signal. Reference numeral 6 denotes a break in the electric circuit 3, and X denotes an advance warning circuit inserted between the output wire 4a of the secondary winding 4. It consists of a resistor 7 and a light emitting diode 8, and the operating sensitivity current of the break breaker. Operate at a value lower than the value. That is, the advance warning is notified by emitting light. L is the load.

In the present invention, as described above, the advance warning circuit X consisting of the light emitting diode 8 and the resistor 7 is inserted between the secondary output lines of the current transformer 1, so that the light emission of the light emitting diode 8 is interrupted before the shingle breaker 6 operates. Therefore, an advance warning can be issued and necessary measures can be taken, and furthermore, if a large current such as a ground fault current flows as an unbalanced current, or if there is contact between the primary and secondary sides, an abnormal secondary of the current transformer 1 can be detected. The amplifier 2 downstream of the current transformer 1 can be protected from voltage rise, and even if the amplifier 2 fails or the tripping electromagnet 5 is disconnected, etc., the advance warning circuit X can be protected. As a result, there are effects such as being able to notify of a current leakage state.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a conventional example, and FIG. 2 is a circuit diagram of an earth leakage or disconnection circuit according to the present invention. 1...Current transformer, 4...Secondary winding, 5...Electromagnet, 6...Shipping section, X...Advance warning circuit, 7...
...Resistor, 8...Light emitting diode.

Claims (1)

[Claims] 1 The secondary output of the zero-phase current transformer generated by the unbalanced current flowing between the electrical circuits is input to the amplifier, the output of this amplifier drives the tripping electromagnet, and the tripping electromagnet is Therefore, in an earth leakage circuit or disconnector that opens a cable break provided in an electric circuit, a current value lower than the operating sensitivity current value of the cable disconnector is applied between the secondary output line of the current transformer. A leakage or disconnection device characterized by the insertion of an advance warning circuit consisting of an operating light emitting diode and a resistor.