JPH05325766A - Monitoring device for trip circuit - Google Patents

Abstract

PURPOSE:To provide a simplified monitoring device of a trip circuit having the reduced number of control cables and auxiliary relays. CONSTITUTION:A monitoring device is provided with circuit breaker auxiliary (a) contact points 21 connected in series with trip contact points 1 via a control cable 12a and circuit breaker auxiliary (b) contact points 22 connected in parallel with a resistor 31 and the circuit breaker auxiliary (a) contact points 21. A trip coil 23 is connected in series with the circuit breaker auxiliary contact points 21, 22, and it operates a circuit breaker main contact point 25 when a current of the preset value or above flows to interlock the circuit breaker auxiliary contact points 21, 22. A timer is operated when an auxiliary relay 3 connected in parallel with the trip contact points 1 is de-excited, and a warning output is issued when the operating time of the timer becomes longer than the operating time of the trip contact points 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device for a trip circuit used in a power breaker.

[0002]

2. Description of the Related Art FIG. 5 is a circuit diagram showing a conventional monitoring device for a trip circuit, in which 1 is a trip contact and 3 is a trip contact.
Is an auxiliary relay connected in parallel with the trip contact 1 together with the resistor 2. 4 is a resistor, 5 is an auxiliary relay connected in series to the resistor 4, 3a and 5a are a contacts of the auxiliary relays 3 and 5, 6 is a timer-relay, 6b is a time limit b contact, and 11 and 13 are direct current It is a control power supply.

Reference numerals 12a to 12c are control cables, 21 is a circuit breaker auxiliary a contact whose one end is connected to the control cables 12a and 12b, and 22 is a circuit breaker auxiliary b whose one end is connected to the control cable 12c. A contact, 23 is a trip coil of the circuit breaker, 24 is an operation mechanism of the circuit breaker, and 25 is a main contact of the circuit breaker.

Next, the operation will be described. In the trip circuit monitoring device shown in FIG. 5, the normal circuit breaker main contact 25
Is supplying power in the on state. In this case, since the circuit breaker auxiliary a contact 21 is turned on and the circuit breaker auxiliary b contact 22 is turned off by the operation of the operation mechanism 24 of the circuit breaker, the circuit is + of the DC control power supply 11, the resistor 2, the auxiliary relay 3 , The control cable 12a, the circuit breaker auxiliary a contact 21, the trip coil 23 and the DC control power supply 11 are closed. At this time, since the auxiliary relay 3 is excited to turn on the a contact 3a, the timer-relay 6 is turned on to turn off the time limit b contact 6b and output that there is no abnormality in the trip circuit.

If an abnormality occurs in the trip circuit and the control cable 12a is broken, for example, the circuit described above is not closed, the auxiliary relay 3 is demagnetized, and the a contact 3a is turned off and the timer is turned off. After a predetermined time due to demagnetization of the relay 6, the time limit b contact 6b is turned on, and the fact that an abnormality has occurred in the trip circuit is output.

If the trip circuit 1 is turned on while the circuit breaker main contact 25 is in the ON state and power is being supplied when the trip circuit 1 is turned on, the circuit is + of the DC control power supply 11, the trip contact 1, Control cable 12a, circuit breaker auxiliary a contact 21, trip coil 23, and DC control power supply 1
Since it is closed by-of 1, the trip coil 23 is excited by a large current exceeding the moving value, and the operation mechanism 24 of the circuit breaker turns off the circuit breaker main contact 25 and the circuit breaker auxiliary a contact 21. Off, circuit breaker auxiliary b contact 22
Turn on. When the circuit breaker auxiliary b contact 22 is turned on, the circuit formed by the control cable 12b, the resistor 4, the auxiliary relay 5, the control cable 12c and the circuit breaker auxiliary b contact 22 is closed. When the relay 5 is excited and the a contact 5a is turned on, the alarm output at the time of trip circuit abnormality is not erroneously issued.

Next, when the trip contact 1 is turned on while the power supply is cut off while the breaker main contact 25 is off, the circuit breaker auxiliary a contact 21 is off and the circuit breaker auxiliary b.
Since the contact 22 is on, the circuit is the DC control power supply 11
+, Trip contact 1, control cable 12a, control cable
Bull 12b, resistor 4, auxiliary relay 5, control cable 1
2c, the circuit breaker auxiliary b contact 22, the trip coil 23 and the DC control power supply 11 are closed. Although a small amount of current corresponding to the resistor 4 flows through the trip coil 23, the trip coil 23 has a high moving value and is not excited so that the circuit breaker main contact 25 does not operate.

Further, when the power supply is cut off with the breaker main contact 25 turned off, the control cable 12a,
If at least one of the control cables 12b and 12c is broken, the above-mentioned circuit is not closed, the auxiliary relays 3 and 5 are demagnetized, and therefore the a contacts 3a and 5a are turned off and the timer-relay is turned off. After a predetermined time due to demagnetization of 6, the time delay b contact 6b is turned on, and the fact that an abnormality has occurred in the trip circuit is output.

[0009]

Since the conventional trip circuit monitoring device is constructed as described above, the control cable is not required.
In addition to the cable 12a, two control cables 12b and 12c
However, there is a problem in that the circuit becomes complicated and the circuit abnormality must be output due to the disconnection of the complicated circuit itself.

The invention of claim 1 has been made to solve the above-mentioned problems, and it is an object of the invention to reduce the number of control cables and the number of auxiliary relays to obtain a simplified trip circuit monitoring device. To aim.

It is an object of the invention of claim 2 to further reduce the number of auxiliary relays, eliminate an alarm output section, and obtain a more simplified trip circuit monitoring device.

[0012]

According to a first aspect of the present invention, there is provided a trip circuit monitoring device including a circuit breaker auxiliary a contact connected in series to a trip contact via a control cable, and a circuit breaker together with a resistor. A circuit breaker auxiliary b contact connected in parallel to the auxiliary a contact, and a circuit breaker auxiliary contact that is connected in series to both circuit breaker auxiliary contacts and activates the circuit breaker main contact when a current of a predetermined value or more flows and links both circuit breaker auxiliary contacts. It is equipped with a trip coil and an alarm output part that sends out an alarm output when the auxiliary relay connected in parallel to the trip contact is demagnetized and the timer operates and this operation time is longer than the operation time of the trip contact. is there.

According to a second aspect of the present invention, there is provided a trip circuit monitoring device, wherein a circuit breaker auxiliary a contact connected in series to a trip contact via a control cable and a resistor connected in parallel to the circuit breaker auxiliary a contact. A circuit breaker auxiliary b contact, a trip coil connected in series to both circuit breaker auxiliary contacts, which activates the circuit breaker main contact when a current of a predetermined value or more flows, and which trips both circuit breaker auxiliary contacts. And a display unit connected in parallel to the contact.

[0014]

In the trip circuit monitoring device according to the present invention, since the normality of the trip circuit can be confirmed by exciting one auxiliary relay, another auxiliary relay and a control cable associated with another auxiliary relay are unnecessary. To

In the trip circuit monitoring device according to the second aspect of the present invention, since the normality of the trip circuit can be confirmed by the display unit that displays when a current flows in the parallel circuit of the trip contacts, the trip circuit monitoring device is associated with the auxiliary relay and its auxiliary relay. The control cable and alarm output section are not required.

[0016]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a trip circuit monitoring device according to an embodiment of the present invention. In FIG. 1, 1 is a trip contact, 3 is a resistor 2 and an auxiliary relay connected in parallel to the trip contact 1. is there. 3b is a b-contact, 6 is a timer-relay, 6a is a time-delayed a-contact, 11 and 13 are direct-current control power supplies, and b-contact 3b, a timer-relay 6, a time-delayed a-contact 6a and a direct-current control power supply 13 provide an alarm output section. Constitute.

Reference numeral 12a is a control cable, 21 is a circuit breaker auxiliary a contact connected to the control cable 12a, 22 is a circuit breaker auxiliary b contact connected in parallel with the circuit breaker auxiliary a contact 21 together with the resistor 31, and Reference numeral 23 is a circuit breaker trip coil, 24 is a circuit breaker operating mechanism, and 25 is a circuit breaker main contact.

Next, the operation will be described. In the trip circuit monitoring device shown in FIG. 1, the normal circuit breaker main contact 25
Is supplying power in the ON state. In this case, since the circuit breaker auxiliary a contact 21 is turned on and the circuit breaker auxiliary b contact 22 is turned off by the operation of the operation mechanism 24 of the circuit breaker, the circuit is + of the DC control power supply 11, the resistor 2, the auxiliary relay 3 , The control cable 12a, the circuit breaker auxiliary a contact 21, the trip coil 23 and the DC control power supply 11 are closed. At this time, the auxiliary relay 3 is excited to turn off the b contact 3b, so that the timer-relay 6 is demagnetized to make the time delay a contact 6a.
Is turned off to output that there is no abnormality in the trip circuit.

Here, if an abnormality occurs in the trip circuit and the control cable 12a is broken, for example, the above-mentioned circuit is not closed, the auxiliary relay 3 is demagnetized, and therefore the b contact 3b is turned on and the timer is turned on. -After a predetermined time due to the excitation of the relay 6, the time delay a contact 6a is turned on, and the fact that an abnormality has occurred in the trip circuit is output.

When there is no abnormality in the trip circuit and power is being supplied with the circuit breaker main contact 25 turned on,
When the trip contact 1 is turned on, a large current exceeding the moving value flows in the trip coil 23, so that the main circuit breaker main contact 25 is turned off by the operation of the operating mechanism 24 of the circuit breaker and the circuit breaker auxiliary a contact 21 is turned on. Off, circuit breaker auxiliary b contact 22 is turned on. Further, when the trip contact 1 is turned on, both ends of the trip contact 1 are short-circuited, so that no current flows through the resistor 2 and the auxiliary relay 3, and therefore the b contact 3b is turned on. b contact 3
When b is turned on, the timer relay 6 turns on the contact 6a for a predetermined time after a predetermined time. The predetermined time set by the timer is from when the trip contact 1 is turned on until it is turned off again. Since it is set longer than the time, the trip contact 1 is turned off and the auxiliary relay 3 is excited before the timed a contact 6a is turned on, and the b contact 3b is turned off. It will not be emitted.

Next, when the trip contact 1 is turned on when the supply of electric power is cut off while the main breaker contact 25 is off, the circuit breaker auxiliary a contact 21 is off and the circuit breaker auxiliary b.
Since the contact 22 is on, the circuit is the DC control power supply 11
+, The trip contact 1, the control cable 12a, the circuit breaker auxiliary b contact 22, the resistor 31, the trip coil 23, and the DC control power supply 11 are closed. Trip coil 2
A small amount of current corresponding to the resistor 31 flows through 3, but since the trip coil 23 has a high moving value, it is not excited and the circuit breaker main contact 25 does not operate.

When the main contact 25 of the breaker is off and the power supply is cut off, the control cable 12a
Is disconnected, the above-mentioned circuit is not closed, the auxiliary relay 3 is demagnetized, and therefore the b contact 3b is turned on, and after the predetermined time due to the excitation of the timer-relay 6, the time delay a contact 6a is turned on and the trip occurs. Outputs that a circuit error has occurred.
Note that the time chart showing the operation of the trip circuit is shown in FIG.
FIG. 3 shows a time chart showing the operation when an abnormality occurs in the trip circuit.

Example 2. FIG. 4 is a circuit diagram showing a trip circuit monitoring device according to an embodiment of the present invention.
In the figure, reference numeral 32 denotes a lamp as a display unit, and other reference numerals that are the same as those in the first embodiment have the same configurations as those in the first embodiment.

Next, the operation will be described. When there is no abnormality in the trip circuit and power is being supplied with the circuit breaker main contact 25 turned on, the circuit is the + of the DC control power supply 11, the resistor 2, the lamp 32, the control cable 12a, the circuit breaker auxiliary. a-contact 21, trip coil 23, and DC control power supply 1
Closed with a 1-. At this time, the lamp 32 lights up,
Display that the trip circuit is normal.

If the control cable 12a is disconnected, the above-mentioned circuit is not closed and the lamp 32 is turned off.
Indicates that an error has occurred in the trip circuit. Also, when the trip circuit 1 is turned on while the power is being supplied while the main contact 25 of the circuit breaker is on, there is no abnormality in the trip circuit, and both ends of the trip contact 1 are short-circuited. No current flows through the resistor 2 and the lamp 32, so the lamp 32 is turned off, but when the trip contact 1 is restored and turned off, the lamp 32 is turned on again.
It is possible to detect that the trip circuit is normal.

In the above embodiment, the timer-relay 6
Although a time limit is provided to prevent unnecessary output transiently, it may be a mere delay relay. Further, the resistor 2 for adjusting the current value flowing through the auxiliary relay 3 or the lamp 32 can be omitted. Further, in the above embodiment, the case of the circuit breaker has been described, but the same effect can be obtained even with a disconnecting switch or another switch.

[0027]

As described above, according to the first aspect of the present invention, the circuit breaker auxiliary a contact connected in series to the trip contact via the control cable and the resistor parallel to the circuit breaker auxiliary a contact. A circuit breaker auxiliary b contact connected, a trip coil connected in series with the circuit breaker auxiliary contact, which activates the circuit breaker main contact when a current of a predetermined value or more flows, and also operates the circuit breaker auxiliary contact, and the trip contact Since the timer is activated when the auxiliary relay connected in parallel with is demagnetized, and the alarm output section sends out an alarm output when the operation time is longer than the operation time of the trip contact, it is configured as one unit. Excitation of the auxiliary relay makes it possible to confirm the normality of the trip circuit and eliminates the need for other auxiliary relays and control cables associated with the other auxiliary relays. Therefore,
The number of control cables and the number of auxiliary relays are reduced, and a simplified and highly reliable and inexpensive trip circuit monitoring device can be obtained.

According to the second aspect of the present invention, a circuit breaker auxiliary a contact connected in series to the trip contact via a control cable, and a circuit breaker auxiliary b connected in parallel with the circuit breaker auxiliary a contact together with the resistor. A contact, a trip coil that is connected in series to the circuit breaker auxiliary contact, activates the circuit breaker main contact when a current of a specified value or more flows, and interlocks the circuit breaker auxiliary contact, and a display unit connected in parallel to the trip contact. Since the configuration is provided with and, the normality of the trip circuit can be confirmed by the simple display section, and the auxiliary relay, the control cable and the alarm output section associated with the auxiliary relay are not required. Therefore, the number of auxiliary relays and the alarm output section are reduced, and it is possible to obtain a simplified, highly reliable and inexpensive trip circuit monitoring device.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a trip circuit monitoring device according to an embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the trip circuit.

FIG. 3 is a time chart showing an operation when an abnormality occurs in the trip circuit.

FIG. 4 is a circuit diagram showing a monitoring device for a trip circuit according to an embodiment of the present invention.

FIG. 5 is a circuit diagram showing a conventional trip circuit monitoring device.

[Explanation of symbols]

 1 Trip contact 3 Auxiliary relay 3b b contact (alarm output part) 6 Timer-relay (alarm output part) 6a Timed a contact (alarm output part) 12a Control cable 13 DC control power supply (alarm output part) 21 Circuit breaker auxiliary a-contact 22 Circuit breaker auxiliary b-contact 23 Trip coil 25 Circuit breaker main contact 31 Resistor 32 Lamp (display)

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[Procedure amendment]

[Submission date] December 21, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (2)

[Claims] 1. A circuit breaker auxiliary a-contact connected in series to a trip contact via a control cable, and a circuit breaker auxiliary connected in series to a resistor and connected in parallel to the circuit breaker auxiliary a-contact together with the resistor. The b contact, a trip coil connected in series to the circuit breaker auxiliary contact connected in parallel and actuating the circuit breaker main contact when a current of a predetermined value or more flows, and a trip coil for interlocking the circuit breaker auxiliary contact, and the trip contact Monitoring of trip circuit equipped with auxiliary relay connected in parallel and alarm output section that outputs a warning output when the auxiliary relay is demagnetized and the timer operates and the operation time is longer than the operation time of the trip contact apparatus. 2. A circuit breaker auxiliary “a” contact connected in series to a trip contact via a control cable, and a circuit breaker auxiliary “a” circuit connected in series to a resistor and connected in parallel to the circuit breaker auxiliary “a” contact together with the resistor. The b contact, a trip coil connected in series to the circuit breaker auxiliary contact connected in parallel and actuating the circuit breaker main contact when a current of a predetermined value or more flows, and a trip coil for interlocking the circuit breaker auxiliary contact, and the trip contact A trip circuit monitoring device including a display unit connected in parallel.