JPH04126317A - Tripping circuit for breaker - Google Patents

Abstract

PURPOSE:To securely break in case of an accident and disconnect a section where the accident occurs by duplicating a tripping circuit of a breaker. CONSTITUTION:A first tripping circuit 1 is constructed with a first tripping coil (TC1) and an a-contact (AXa1), both of which are connected to each other, of an auxiliary switch which interlocks with a breaker contacting part. Both are provided between a tripping command end (OP) and a controlling power supply (N), in addition a parallel timer (T) is provided in parallel. A second tripping circuit 2 is constructed with a contact (Ta) which closes when the timer (T) operates, a second tripping coil (TC2), and an a-contact (AXa2) of an auxiliary switch which interlocks with the breaker contacting part, and positioned between controlling power supplies (P). (N) to be parallel with the first tripping circuit 1. In this case, the breaker does not operates and the contact (AXa2) of the auxiliary switch remains closed when a trouble such as a disconnection of the first tripping coil (TC1) occurs in the first tripping circuit 1, then the second tripping circuit 2 closes when the contact (Ta) of the timer (T) closes. Thus, secure tripping is possible.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a circuit breaker tripping circuit.

``Prior art'' A circuit breaker connects and disconnects electrical circuits, and in particular, when an accident occurs on an electrical circuit, it receives and receives signals from a protective relay to reliably disconnect the electrical circuit and close the fault area. This plays an important role in terms of reliability of power supply. Therefore, circuit breaker users systematically stop the power supply to the circuit and inspect mainly the protective relay and operating mechanism.
It is difficult to shut down the system during periods such as summer when electricity demand is high, and it is precisely during these times that it is necessary to operate in the event of an accident. For this reason, measures have been taken to supply a small amount of current to the tripping circuit of the circuit breaker body and to monitor disconnections in the tripping circuit, especially in the tripping coil.

``Problems to be Solved by the Invention'' Conventional disconnection monitoring of tripping circuits is carried out to avoid malfunction when the tripping circuit is disconnected.
If an accident occurs before you can deal with it, the circuit breaker will not operate.
It is not possible to minimize the scope of the accident. Also,
In order to monitor disconnection, it is necessary to constantly supply a small current to the tripping enclosure. Therefore, not only is a device for passing a minute current (hereinafter referred to as an energizing device, e.g. a current limiter) required, but the tripping coil is in a closed circuit through a constantly energizing device, so if the energizing device is In the event of a short circuit, the tripping coil will operate, causing a malfunction of the circuit breaker and causing a power outage.

Therefore, the present invention has dual tripping circuits, so that even if the first tripping circuit is abnormal, the second tripping circuit operates, and the circuit breaker is able to shut off in the event of an accident, which is an important role played by the circuit breaker.
The purpose of this invention is to more reliably separate the accident section, eliminate the need for an energizing device, and prevent accidents caused by this energizing device.

"Means for Solving the Problem" The present invention provides two sets of tripping circuits in a circuit breaker, so that both outputs are transmitted to the circuit breaker contact part through the same circuit breaker operating mechanism, and both By setting a time difference between the operations of the first tripping circuit and using the second tripping circuit as backup protection, even if there is some kind of malfunction in the first tripping circuit and it does not operate as expected, the second tripping circuit will not operate as expected. The trip circuit is activated to enable more reliable tripping. Furthermore, a device is provided that detects a malfunction in the first trip circuit by operating the second trip circuit and issues an alarm, so that the user can be informed of this. Furthermore, the reliability of the device can be improved because the energizing device is not required and there is no need to keep the circuit closed at all times.

"Operation" According to the present invention, the circuit breaker tripping circuit is duplicated,
It is possible to provide more reliable performance, and even if the tripping circuit is malfunctioning, it can perform the specified tripping function and notify the user of the malfunction, preventing serious troubles such as the inability to trip. This can be prevented.

"Example" FIG. 1 shows an embodiment of the present invention.

The first tripping circuit 1 includes a first tripping coil TC1
and the a contact AX of the auxiliary switch that interlocks with the circuit breaker contact part.
al is connected between the trip command terminal OP and the control power source N, and a timer T is provided in parallel thereto. The second tripping circuit 2 includes a contact Ta that closes when the timer T operates, a second tripping coil TC2, and an auxiliary switch a that is interlocked with the circuit breaker contact part.
The contact AXa2 is provided between the control power supplies P and N so as to be parallel to the first tripping circuit 1.

Next, the operation of the above embodiment will be explained. When there is a tripping operation, the circuit breaker is in the closed state, the a contact AXal of the auxiliary switch interlocked with the circuit breaker contact is closed, and the first tripping circuit 1 is in the closed state. Therefore, when a trip command is input to the trip command terminal OP, the first trip coil T
C1 is energized, pushes the trip lever 5 in the operating mechanism 4, releases the latched state, and performs a trip operation. and,
The timer T is activated by the same command, and the contact Ta of the second tripping circuit 2 is closed after a certain set time.

Here, the setting time of timer T is 0, 3, which is generally used for time-limited coordination of protective relays between upper and lower levels in power systems.
Considering cooperation with the cutoff time, it is considered preferable to set the time period to be shorter than 0.1 to 0.2 seconds. As a result, when the circuit breaker operates normally in the first tripping circuit 1, the a contact AXa2 of the auxiliary switch opens before the contact Ta of the timer T closes, and the second tripping circuit 2 becomes open. Therefore, even if contact Ta of timer T closes, the second
The tripping coil TC2 is not energized.

However, if there is a malfunction in the first tripping circuit 1, such as a disconnection of the first tripping coil TC1, the circuit breaker will not operate, the auxiliary switch's a contact AXa2 will remain closed, and the timer T's contact Ta will close. When closed, the second trip circuit 2 is in a closed state. Therefore, the second tripping coil TC2 is energized, pushing the tripping lever 5 in the operating mechanism 4, releasing the latched state, and performing a tripping operation.

FIG. 2 shows another embodiment of the present invention, in which an alarm device 3 is added to the above embodiment so that the user can be informed of a malfunction in the first tripping circuit 1.

A relay R is provided in series with the second tripping circuit 2, and a contact Ral and a reset button R that close when the relay R operates are provided.
B is provided in parallel with the second tripping circuit 2 so as to be self-excited when the relay R operates. A contact Ra2 that closes when the relay R operates constitutes an alarm contact.

The operation of this embodiment will be explained below.

When the first tripping circuit 1 operates normally and the circuit breaker performs the tripping operation, the a contact AXa2 of the auxiliary switch becomes open and the relay R does not operate, as in the above embodiment. On the other hand, when there is a malfunction in the first tripping circuit 1, the a contact AXa2 of the auxiliary switch remains closed, energizing the second tripping coil TC2, performing the tripping operation, and relay R , and contact Ral,
Ra2 closes. Here, the circuit breaker operates due to the tripping operation, and the a contact AXa2 of the auxiliary switch opens, but between the control power supplies P and N, the reset button RB and the relay contact R
al, relay R constitutes a closed circuit, and relay R continues to be energized until the reset button RB is pressed, and the contact Rat
, Ra2 remain closed. And relay contact Ra
2, the circuit breaker user is informed of the malfunction of the first tripping circuit 1. The alarm is reset by pressing the reset button RB.

"Effects of the Invention" Even if the first tripping circuit has some kind of malfunction and does not perform the prescribed operation, the second tripping circuit operates to enable more reliable tripping. Furthermore, by operating the second tripping circuit, a malfunction in the first tripping circuit can be detected and an alarm can be issued to notify the user of this.

Furthermore, unlike the prior art, there is no need for an energizing device and there is no need for the tripping circuit to be a normally closed circuit, so it is possible to improve the reliability of the device.

[Brief explanation of drawings]

FIG. 1 shows one embodiment of the present invention, and FIG. 2 shows another embodiment. In the figure, 1... first tripping circuit, 2... second tripping circuit, 3... alarm device, 4... operating mechanism, 5...
Tripping lever, TCl...first tripping coil,
TC2...Second tripping coil, AXal, AXa
2... A contact of the auxiliary switch, T... Timer, T
a...Timer contact, R...Relay, Ral, R
a2...Relay contact, RB...Reset button, P
, N... Control power supply.

Claims (2)

[Claims] (1) A timer T is provided in parallel to the first tripping circuit 1 having the first tripping coil TC1 that operates according to a tripping command so that it operates according to the same command, and further closes when the timer T operates. A second tripping circuit 2 having a contact Ta and a second tripping coil TC2 is provided in parallel, and the second tripping circuit 2 is operated after the first tripping circuit 1 is operated. A circuit breaker tripping circuit characterized by: (2) A circuit breaker tripping circuit according to claim (1), characterized in that the second tripping circuit 2 is provided with an alarm device 3 that issues an alarm when the second tripping circuit 2 operates. .