CN211669312U

CN211669312U - Three-station grounding device for cable voltage withstand test

Info

Publication number: CN211669312U
Application number: CN201922393969.0U
Authority: CN
Inventors: 王广先; 赵瑞影; 黄强; 吴昊
Original assignee: Chint Electric Co Ltd
Current assignee: Chint Electric Co Ltd
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2020-10-13
Anticipated expiration: 2029-12-25

Abstract

The utility model discloses a three station earthing device for cable withstand voltage test, a serial communication port, the structure is the bushing structure, including intermediate conductor and outer insulator, intermediate conductor upper end be equipped with keep apart the ground contact that the sword is connected, the lower extreme is equipped with the screw hole, outer insulator on be equipped with gas tank junction complex bolt hole. The bushing is used as a conventional grounding static contact of a three-station isolating switch in a grounding state, is used as a test socket of a line side cable in an ungrounded state, and can be used for performing direct voltage withstand test verification on the line side cable under the condition of not disassembling a cable head. The grounding sleeve is formed by epoxy casting of a middle conductor and an outer insulator, a grounding contact is arranged at the upper end of a sleeve conductor and can be connected with an isolation knife, and a grounding screw hole is arranged at the other end of the sleeve conductor and is connected with a grounding bar outside the gas tank.

Description

Three-station grounding device for cable voltage withstand test

Technical Field

The utility model relates to a three station earthing device for cable withstand voltage test belongs to switchgear technical field.

Background

When the inflatable cabinet is used for installing the connector parts such as the cable head and the like on site, the requirements on the installation process and the installation quality are very high. The existing supporting cable of the inflating cabinet adopts a cable head plugging structure, namely, a cable head is inserted into an inner cone insulator of the inflating cabinet to be connected, the cable is subjected to conventional maintenance and repair, if the system side is electrified, the cable head can only be detached from the cabinet, and a special cable head test tool is adopted to perform a withstand voltage test on the cable so as to test the performance of the cable. In order to ensure the insulation performance of the cable, the cable head and the inner cone insulator are internally coated with insulating silicone grease and exhaust air in the cavity when being installed, the cable head and the inner cone insulator are very tightly matched after being installed, and the later-stage disassembly is very difficult. If the disassembly mode is improper, the problems of breakage of an inner cone insulator, scratch of a cable head and the like are easily caused, the defects of air leakage of an air box, discharge of a connector component and the like are caused, and even the insulation breakdown fault of the whole cabinet is caused. Therefore, how to reduce or avoid cable head disassembly in the later-period overhaul and maintenance process after the manufacturing and installation of the cables by professionals is an urgent problem to be solved.

Disclosure of Invention

The to-be-solved technical problem of the utility model is how to carry out withstand voltage test to line cable under the condition of not dismantling the cable head.

In order to solve the technical problem, the technical scheme of the utility model a three station earthing device for cable withstand voltage test is provided, its characterized in that, the structure is bushing structure, including intermediate conductor and external insulator, intermediate conductor upper end be equipped with keep apart the ground contact that the sword is connected, the lower extreme is equipped with the screw hole, external insulator on be equipped with gas tank junction complex bolt hole.

Preferably, an annular sealing groove is formed in the joint of the outer insulator and the air box, and an O-shaped sealing ring is arranged in the sealing groove.

The utility model relates to a can carry out three station earthing device of direct withstand voltage test to aerifing the cable on the cabinet, its main characteristic has designed a special three station isolator ground sleeve and has replaced traditional ground connection static contact, and this sleeve pipe uses as three station isolator conventional ground connection static contacts at ground state, then uses as the experimental socket of line side cable at ungrounded state, can carry out direct withstand voltage test to line side cable under the condition of not dismantling the cable head and verify.

Drawings

Fig. 1 is a schematic diagram of the internal structure of a switch cabinet air box using a conventional grounding fixed contact a;

FIG. 2 is a schematic diagram of the internal structure of a switch cabinet air box using the grounding sleeve provided in the present embodiment;

FIG. 3 is a left side schematic view of the structure shown in FIG. 2;

FIG. 4 is a schematic diagram of the operation of the line cable for the withstand voltage test;

fig. 5 is a schematic structural diagram of the grounding sleeve provided in this embodiment.

Detailed Description

In order to make the present invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

Examples

The utility model relates to a can carry out direct withstand voltage test's three station earthing device to aerifing the cable on the cabinet, its main characteristic has designed a special three station isolator earthing sleeve 3, and this sleeve pipe uses as three station isolator conventional ground connection static contacts at ground state. The socket is used as a test socket of the cable at the line side in a non-grounded state, and direct voltage resistance test verification can be carried out on the cable 7 at the line side under the condition that a cable head is not detached.

The common three-station isolating switch body consists of a switch-on static contact 1, an isolating knife 2 and a grounding static contact, and the switch-on and grounding functions of the three-station isolating switch are realized by respectively connecting the isolating knife 2 with the switch-on static contact 1 and the grounding static contact through rotation. The main patent innovation is that a common three-station disconnecting switch grounding static contact is replaced by a grounding sleeve 3 shown in the attached drawing 1, the grounding sleeve is formed by epoxy casting of a middle conductor 301 and an outer insulator 302, a bolt hole and an annular sealing groove are formed in the joint of the middle position of the grounding sleeve 3 and an air box, an O-shaped sealing ring is installed in the sealing groove and is installed on the rear side of the air box, and the O-shaped sealing ring is in airtight connection with the contact surface of the air box. The upper end of the sleeve conductor 301 is a grounding contact which can be connected with the isolation knife, and the lower end is a grounding threaded hole which is connected with the grounding bar 4 and the grounding bar 5 outside the gas tank. The grounding bar 4 is in three-phase short circuit with the grounding sleeve, one end of the grounding bar 5 is connected with the grounding bar 4, and the other end of the grounding bar is connected with the air box shell and grounded.

Line side grounding operation flow: as shown in fig. 2, the

grounding bars

4 and 5 are connected with the grounding threaded hole at the lower end of the grounding sleeve 3 through bolts, and the three-position disconnecting switch is operated to enable the isolating knife 2 of the three-position disconnecting switch to rotate to the position of the grounding sleeve 3 until the isolating knife is completely contacted with the grounding contact at the upper end of the grounding sleeve. At the moment, the three-position isolating switch is in the grounding position, and the grounding of the line side is completed.

The operation flow of the withstand voltage test of the cable at the line side is as follows: after the line side grounding operation is completed, the

grounding bars

4, 5 are removed leaving the grounding sleeve 3 in an ungrounded state, as shown in fig. 3. This patent experimental frock 6 includes middle part metallic conductor and the silicon rubber structure of pouring in the metallic conductor outside, and frock upper portion is equipped with the wiring end and is connected with withstand voltage equipment once, and the lower part is equipped with telescopic fastener, and the inside protruding bolt that is equipped with of fastener, bolt specification and ground sleeve lower extreme ground connection screw hole are supporting. And (3) sleeving a fastener at the lower part of the test tool 6 into the grounding sleeve 3, screwing a bolt in the fastener into a threaded hole of the grounding sleeve and screwing and fastening, and finishing the preparation work of the cable voltage withstand test. The upper part of the test tool is connected with test equipment, so that the withstand voltage test can be directly carried out on the cable 7. After the cable voltage withstand test is completed, the test tool 6 is detached, and the

grounding bars

4 and 5 are reinstalled to be restored to the initial state.

The grounding sleeve 3 is located on the rear side of the upper air box of the switch cabinet and is in a closed state at ordinary times, and the protection level is high and is not easy to touch. The operation flow is simple, safe and fast when the cable head and the cable are tested.

This patent three-station earthing device for cable withstand voltage test has realized the quick nimble conversion of three-station isolator ground connection static contact and cable withstand voltage test socket function, uses as three-station isolator ground connection static contact at the ground state, then uses as the test socket of line side cable at ungrounded state, can carry out direct withstand voltage test verification to line side cable under the condition of not dismantling the cable head. Simple structure, convenient operation have improved cubical switchboard use operation and maintenance's maneuverability and reliability.

Claims

1. The utility model provides a three station earthing device for cable withstand voltage test which characterized in that, the structure is the bushing structure, including intermediate conductor (301) and outer insulator (302), intermediate conductor (301) upper end be equipped with keep apart the ground contact that sword (2) are connected, the lower extreme is equipped with the screw hole, outer insulator (302) on be equipped with gas tank junction complex bolt hole.

2. The three-station grounding device for the cable withstand voltage test is characterized in that an annular sealing groove is formed at the joint of the outer insulator (302) and the air tank, and an O-shaped sealing ring is arranged in the sealing groove.