JPH0130754Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to prevention of repetitive operation of the closing circuit, in particular, among control circuits for switches and disconnectors that operate using energy such as springs, hydraulic pressure, pneumatic pressure, etc.

Conventionally, there has been a device of this type as shown in FIG. In the figure, 1 is a motor that stores input energy (not shown), such as a spring, and 2b
3 is a control switch normally closed contact that operates when energy storage is completed, and 3 is a closing latch (not shown) that releases the stored energy and closes the main contact (not shown) of the switch. A closing coil, 4 a repetitive operation prevention relay (hereinafter referred to as a relay) for preventing repetitive operation of the closing coil, 4b, this relay 4;
2a is the control switch normally open contact that operates in conjunction with the control switch normally closed contact 2b, 5b is the normally closed contact of the auxiliary switch that operates in conjunction with the main contact of the switch, 5a is also the auxiliary Normally open contacts of switchgears,
6 is a tripping coil that drives a tripping latch for tripping the main contact of the switch; 7 is a closing switch that provides a closing command; and 8 is a tripping switch that provides a tripping command.

Next, the operation will be explained. When a voltage is applied to parts A and B of the control circuit configured as described above, the motor 1 is first operated to store the input energy of a spring or the like. When the energy storage operation is completed, the control switch operates, the normally closed contact 2b of the control switch opens to stop the motor 1, and at the same time the normally open contact 2a of the control switch closes, and when the closing switch 7 is operated, the auxiliary switch normally closes. A current flows through the closing coil 3 through the closing contact 5b, the normally open contact 2a of the control switch, and the normally closed contact 4b of the relay 4, driving the closing latch of the switch and closing the main contact of the switch. Due to the operation of the switch, the normally closed contact 5b of the auxiliary switch opens, cutting off the current in the closing coil 3 and commutating the current to the relay 4, operating the relay 4 and opening the normally closed contact 4b of the relay, While the closing switch 7 is operating, the relay 4 is held via the closing coil 3. Therefore, even if the switch is tripped by the operation of the trip switch 8 and the normally closed contact 5b of the auxiliary switch is closed, the closing coil is energized only by the current via the relay, and the closing operation of the switch is interrupted. is not performed, and repeated closing operations are prevented. However, since conventional control devices are configured as described above, a small current flows through the intermediate closing coil while the closing switch is operating, so there is a fairly large difference in impedance between the relay and the closing coil (for example, several tens of times). must be attached. Further, since there is a limit on the minimum return voltage of the closing coil, it is difficult to select a relay and there are problems such as difficulty in returning the closing latch of the reclosing function retaining switch.

This invention was developed to eliminate the drawbacks of the conventional ones as described above, and provides a control circuit that has a circuit that can cut off the closing coil current by the operation of the repeat operation prevention relay after the switch closing operation. It is something to do.

An embodiment of this invention will be described below with reference to the drawings.

In Figure 2, 1, 2a, 2b, 3, 4, 5
a, 5b, 6, 7, and 8 are the same as the conventional one in FIG. 4a is the normally open contact of the relay, 4b
is the normally closed contact of the relay.

In the circuit configured as described above, the motor 1 to which voltage is applied to A and B stores energy as in the conventional case, and when the energy storage is completed, the normally closed contact 2 of the control switch
b opens to stop the motor 1, and at the same time the normally open contact 2a of the control switch is closed, forming a closing coil circuit.

Under these conditions, when the closing switch 7 is operated, current flows to the closing coil 3 via the normally closed contact 5b of the auxiliary switch, the normally open contact 2a of the control switch, and the normally closed contact 4b of the relay, and the closing switch 7 is activated. The coil 3 operates and the switch closes. When the normally closed contact 5b of the auxiliary switch opens in conjunction with this closing operation, the current in the closing coil 3 is immediately cut off, and the relay 4 operates via the closing coil 3, and the normally closed contact 4 of the relay
b is opened and the normally open contact 4a of the relay is closed,
By short-circuiting the closing coil 3, the small current flowing through the closing coil 3 is cut off, and the operational relay 4 of the closing switch 7 is kept closed. In this state, the tripping coil 6 is operated by the tripping switch 8, and the switch is tripped to close the normally closed contact 5b of the auxiliary switch.
Even if the terminal is closed, the circuit is closed by the normally closed contact 4b of the relay.
Since it is disconnected, the closing coil 3 circuit is not formed, and the closing operation will not be performed unless the closing switch 7 is opened and operated again. In addition, the motor 1 is connected to the normally closed contact 2 of the control switch by the tripping operation of the switch.
By returning b, energy can be stored regardless of the operation of the input switch 7.

In the above embodiment, independent normally open and normally closed contacts are used as relay contacts, but the same effect can be obtained even if switching contacts having a common fulcrum as shown in FIG. 3 are used.

As described above, according to this invention, since the closing coil current is short-circuited and then disconnected by the contacts of the relay for preventing repetitive operation, a small current does not flow through the always closing coil, and therefore the relay 4 When making a selection, there is no need to consider the impedance of the input coil 3, making the selection easy. Also, the normally open contact 4a of the relay 4 used in this invention
Since the current flowing through the relay is interrupted by the circuit of the make switch 7, this relay contact does not require a break or break container, so a small one can be applied, and the switching contacts unique to small relays can be used effectively. There is.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the configuration of a conventional control device.
FIG. 2 is a circuit diagram showing one embodiment of the present invention, and FIG. 3 is a circuit diagram showing a part of the configuration of another embodiment of the present invention. In the figure, 3... Closing coil, 4... Repetitive action prevention relay, 4a... Repetitive action prevention relay normally open contact,
4b... Repetitive action prevention relay normally closed contact, 5b...
Auxiliary switch normally closed contact, 7... Closing switch. still,
The same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A repetitive action prevention relay and a switch closing coil are connected in series, and at least a normally closed contact of an auxiliary switch that operates in conjunction with the switch and a normally closed contact of the repetitive action prevention relay are connected in series. A control circuit comprising a group of connected control contacts connected in parallel with a repetitive action prevention relay, and a normally open contact of the repetitive action prevention relay connected in parallel with a switch closing coil. (2) The control circuit according to claim 1, characterized in that the normally closed and normally open contacts of the repeat operation prevention relay are constituted by a set of switching contacts (c contacts). (3) The control circuit according to claim 1, wherein after the switch closing coil is operated, the closing coil is short-circuited and the closing coil current is cut off by operation of a repeat operation prevention relay.