JPH085659A - Test plug for insertion test terminal - Google Patents

Abstract

PURPOSE:To facilitate the operation test by setting the length of a contactor for phase N shorter than that for other phase thereby preventing the erroneous function of a protective circuit at the time of inserting a test plug. CONSTITUTION:Contactors 36N, 46N are arranged side by side while projecting shorter than contactors 45B-45R and in the way of insertion of a test plug 30A into a test terminal body 5, the contactors 45B-45R touches the contact parts 12, 22 only after touching the subcontact parts 12, 22 of a contact unit 10. The length of the plug 30A is set such that the plug 30A is pressed against the main contact parts 13, 23 when it is inserted perfectly into the body 5 to establish an electrically conducting state and the contacts 14, 24 can be separated from interconnecting contacts 16, 26. Consequently, the contact 17 (27) is connected through a supporting conductor 15 (25), the contact part 12, 13 (22, 23), and the contactor 36N (46N) with the terminal 37 (47). Since the neutral point N connected with the terminal 17 is separated from a ground overcurrent relay connected with the terminal 27, operation test of the protective circuit can be carried out easily through the plug 30A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test plug of an insert type test terminal for performing an operation test of an overcurrent relay, a ground fault overcurrent relay, etc. in a protective relay board or the like.

[0002]

2. Description of the Related Art Conventionally, for example, there is a protection circuit as shown in FIG. 6 as an electrical protection system for electric equipment for power transmission and distribution. This protection circuit consists of bus bars 50B, 50W, 50R.
Current transformers 51B, 51W, 51R are provided for each phase of, and one end side thereof is connected to the neutral point N, and
The other ends are overcurrent relays 53B, 53W, 53R, respectively.
Connected to each overcurrent relay 53B, 53W, 5
A ground fault overcurrent relay 55 is provided between the 3R and the neutral point N. For example, based on a signal from the ground fault overcurrent relay 55, it is provided between the busbars 50B, 50W, 50R and the transformer 57. The circuit breaker 59 is configured to control the circuit break. In the following, the current transformers 51B, 51W, 51
Each phase of R is called B, W, R phase, and the phase connected to the neutral point N is called N phase.

In such a protection circuit, the test terminal body 5 is provided between the overcurrent relay 53B, 53W, 53R, the ground fault overcurrent relay 55 and each of the current transformers 51B, 51W, 51R.
After connecting the test device 60 equipped with an instrument, a current generator, etc. to the test plug 30, this is inserted into the test terminal body 5, and the busbars 50B, 50W, 50R are kept in a live state. The above relays were tested.

An outline of the test terminal body 5 will be described with reference to FIG. FIG. 7 is a vertical cross-sectional view of the test terminal main body 5. In the box body 6 having the plug insertion port 7, four contact devices 10 correspond to each of the B, W, R and N phases. Are installed side by side.

This contact device 10 includes sub-contact parts 12 and 2.
2, main contact portions 13 and 23, a pair of upper and lower movable contact plates 11 and 21 each having contacts 14 and 24, and support conductors 15 and 25, which are connected to terminals 17 and 27, respectively. . Reference numerals 16 and 26 are relay contacts, and 18 is a compression coil spring. The terminal 17 is connected to, for example, the current transformer 51B, and the terminal 27
Is connected to the overcurrent relay 53B and is interposed in the protection circuit.

Further, in the conventional test plug 30, as shown in FIG. 8, a pair of contacts 35B, which correspond to each phase and are vertically insulated from each other, are provided on the insulating plate 32 protruding from the base 31. 45B, 35W, 45W, 35R, 45
R, 35N, and 45N are arranged in parallel, and the base ends thereof are connected to four sets of terminals 37 and 47 arranged coaxially, respectively.

In this test plug 30, for example, four terminals 37 are connected and connected by a plurality of short-circuit pieces 38, and a test device 60 is connected to the other terminals 47 and used for testing a protection circuit. It had been. In the state where the test plug 30 is not inserted in the test terminal body 5, the support conductor 15, the relay contact 16, and the contact 2 are provided between the terminals 17 and 27.
4, movable contact plate 21, support conductor 25, and support conductor 2
5, the relay contact 26, the contact 14, the movable contact plate 11, and the support conductor 15 are in a closed state, and for example, the current transformer 51B
Forms a closed circuit with the overcurrent relay 53B and the ground fault overcurrent relay 55.

When the test plug 30 is inserted into the test terminal body 5 in the test of the overcurrent relays 53B, 53W, 53R and the ground fault overcurrent relay 55, the contacts 14 and 24 and the relay contacts 26 and 16 of each contact device 10 are inserted. And are separated.
Then, for example, the connection between the current transformer 51B and the overcurrent relay 53B is cut off, and both ends of the current transformers 51B, 51W, 51R are short-circuited by the short-circuit piece 38, and the overcurrent relays 53B, 53W, 53R and the ground. Overcurrent relay 55
Are connected to the test apparatus 60.

[0009]

However, in the test plug of the insertion type test terminal having such a conventional structure, the following problems occur when the plug is inserted.

That is, when the test plug 30 is inserted obliquely with respect to the plug insertion axis at the start of plug insertion, for example, the contact 35B comes into contact with the sub contact portion 12 of the contact device 10 later than the contact 35N ( The contact at the intermediate position between the two is already in contact with the corresponding sub-contact portion), and as shown by the dotted arrow in FIG. 9, an imbalance occurs in the B, W, and R phase currents, and the B phase The current passes through the overcurrent relay 53B to activate the ground fault overcurrent relay 55. Therefore, there is a problem that the circuit breaker 59 is driven and the bus bar is cut off.

In order to avoid this, conventionally, the test plug 30 was inserted after the ground fault overcurrent relay 55 was relay-locked and the interruption operation by it was stopped.
Therefore, it takes time to prepare for the test, and moreover, such a protection circuit is generally mounted in parallel on the protective relay panel, and extra caution is required to prevent erroneous operation. There was a problem.

The present invention has been made in view of the above, and it is an object of the present invention to prevent malfunction of the protection circuit at the time of inserting a test plug and to easily perform an operation test of the protection circuit. It is intended to provide a test plug for an insertable test terminal.

[0013]

The present invention has been made in order to achieve the above-mentioned object, and a plurality of current transformers provided at each phase of the busbar and having one end connected to a neutral point, and one end A plurality of overcurrent relays respectively connected to the other end side of the plurality of current transformers, a ground fault overcurrent relay provided between the other end of the plurality of overcurrent relays and the neutral point, A protection circuit having a plurality of sets of contact devices provided between the current transformer and the overcurrent relay and between the neutral point and the ground fault overcurrent relay, respectively, and capable of separating between them. A test terminal body, and a test plug that is formed to be insertable into the test terminal body and that is fixed to the upper and lower surfaces of an insulating plate and that has a plurality of sets of contacts that can contact the plurality of sets of contact devices, respectively. Insertion type test terminal,
In the test plug, the length of the contact inserted into the contact device between the neutral point and the ground fault overcurrent relay is greater than the length of the contact inserted into the contact device between the current transformer and the overcurrent relay. It is a test plug of an insertion type test terminal characterized by being formed in a short shape.

[0014]

The present invention is constructed as described above. When the test plug is inserted into the test terminal body with its current transformer side short-circuited, the current transformer and each overcurrent relay are inserted in the middle of the insertion. All the contacts in between contact the corresponding contact device, and the contact between the neutral point side of each current transformer and the ground fault overcurrent relay is not in contact with the corresponding contact device.

In this state, the other end of each current transformer is short-circuited and the ground fault overcurrent relay is kept inactive.
This state is maintained until all contacts between each current transformer and each overcurrent relay come into contact with the corresponding contact device even when the test plug is inserted diagonally, and the ground fault overcurrent relay is not The operating state is maintained.

When the test plug is completely inserted, the contact between the neutral point and the ground fault overcurrent relay contacts the contact device, and each current transformer is short-circuited, and each overcurrent relay and ground fault overcurrent relay is connected. The relay is separated from each current transformer, and the test circuit of the insertion type test terminal is ready to test the protection circuit.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the test plug of the insertable test terminal of the present invention will be described below with reference to the drawings. It should be noted that, in the following, common parts with the conventional example are denoted by common reference numerals, and redundant description will be omitted.

FIGS. 1 and 2 show an embodiment of the present invention. A test plug 30A in this embodiment has a pair of upper and lower contacts 35B, 45B insulated from each other on an insulating plate 32A protruding from a base 31. 35W, 45W, 35R, 45R are arranged in parallel with their tip portions aligned, and a pair of upper and lower contacts 36N, 46N having a shorter projecting length than those are arranged in parallel while being insulated from each other. ing.

The contacts 36N and 46N are the test plug 30.
When A is inserted into the test terminal body 5 under arbitrary conditions, FIG.
As shown in FIG.
Until B, 35W, 45W, 35R, 45R come into contact with the sub-contact parts 12, 22 of the contact device 10 of each system (including the state in which the test plug 30A is obliquely inserted).
The lengths of the contacts 36N and 46N are set so as not to come into contact with the sub contact portions 12 and 22 of the contact device 10 of the system.

Further, the lengths of the contacts 36N and 46N are
As shown in FIG. 4, the test plug 30A has the test terminal body 5
The main contact portion 1 of the contact device 10 in the completely inserted state
The relay contact 2 is formed by pressing and contacting the contacts 3 and 23 to form an electrical conduction state, and the contacts 14 and 24 facing each other.
The length is set so that it can be separated from Nos. 6 and 16.

In the fully inserted state of the test plug 30A shown in FIG. 4, for example, the contacts 36N and 46N are electrically connected to the sub contact portions 12 and 22 and the main contact portions 13 and 23, respectively.
Contact 14 and relay contact 26 and contact 24 and relay contact 16
And are separated.

Therefore, the terminal 17 includes the support conductor 15 → the sub contact portion 12 and the main contact portion 13 of the movable contact plate 11 → the contact 36N.
→ Connected to the terminal 37. The terminal 27 is the support conductor 2
5 → Sub contact part 22 of movable contact plate 21, main contact part 23 → contact 46N → terminal 47. As a result, the neutral point N connected to the terminal 17 and the ground fault overcurrent relay 55 connected to the terminal 27 are separated, and the test plug 30
The operation test of the protection circuit is performed via A.

The present invention is not limited to the above description and the illustrated examples, and its embodiment can be modified without departing from the technical idea of the present invention. For example, as shown in FIG. 5, the N-phase contactor is a test plug 30B composed of a contactor 36N having only a short contact side on the neutral point N side (terminal 17 side in the example) and an insulating plate 32B. However, even if it is, the same effect is produced.

[0024]

As described above, according to the test plug of the insertion type test terminal of the present invention, the N-phase contact is made shorter than the length of the contact of the other phase, so that the test plug is connected to the test terminal body. Upon insertion, contact of the N-phase contact to the contact device can be made after all other phase contacts have contacted the contact device.

Therefore, the N due to the oblique insertion of the test plug, etc.
The preceding contact of the phase contactor can be prevented, and the malfunction of the ground fault overcurrent relay can be prevented. Therefore, it is possible to save the trouble of preparing a relay lock and the like for the operation test of the protection circuit, and unlike the conventional example, no special precautions are required to prevent incorrect operation of the relay lock.
And, there is an effect that can be easily performed.

[Brief description of drawings]

FIG. 1 is a plan view of a test plug of an insertable test terminal according to an embodiment of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a side cross-sectional view during insertion of a test plug into a test terminal body.

FIG. 4 is a side sectional view of the test terminal body when the test plug is completely inserted.

FIG. 5 is a side view showing another example of the test plug.

FIG. 6 is a circuit diagram showing an example of a protection circuit equipped with an insertable test terminal.

FIG. 7 is a side sectional view showing a test terminal body.

FIG. 8 is a perspective view showing a conventional test plug.

FIG. 9 is an explanatory diagram showing an operation test example of a protection circuit.

[Explanation of symbols]

 5 Test Terminal Body 10 Contact Device 30, 30A, 30B Test Plug 32A, 32B Insulation Plate 35B, 35W, 35R Contact 36N Contact 45B, 45W, 45R Contact 46N Contact 51B, 51W, 51R Current Transformer 53B, 53W , 53R Overcurrent relay 55 Ground fault overcurrent relay N Neutral point

Claims (1)

[Claims] 1. A plurality of current transformers each having one end connected to a neutral point provided in each phase of the busbar, and a plurality of overcurrents each having one end connected to the other end side of the plurality of current transformers. In a protection circuit comprising a relay and a ground fault overcurrent relay provided between the other end of the plurality of overcurrent relays and the neutral point, between the current transformer and the overcurrent relay, and A test terminal body having a plurality of sets of contact devices respectively provided between the neutral point and the ground fault overcurrent relay, and having a plurality of contact devices capable of separating between them, and an insulating plate formed so as to be insertable into the test terminal body. An insertion-type test terminal, comprising: a test plug having a plurality of sets of contacts fixed to the upper and lower surfaces and capable of contacting each of the plurality of sets of contact devices, wherein the test plug comprises the neutral point and a ground fault. The length of the contact inserted in the contact device between the current relays Test plugs insertable test terminal to which the composed formed shorter than the length of the inserted contact in the contact device between current transformer and overcurrent relay, it is characterized.