CN210378921U

CN210378921U - Low-voltage distribution protection device

Info

Publication number: CN210378921U
Application number: CN201921459012.5U
Authority: CN
Inventors: 张海峰; 梁国斌; 杨弘诚; 刘勇; 王留庆; 韩礼艳
Original assignee: Qingdao Marine Equipment Research Institute Co ltd
Current assignee: Qingdao Marine Equipment Research Institute Co ltd
Priority date: 2019-09-03
Filing date: 2019-09-03
Publication date: 2020-04-21
Anticipated expiration: 2029-09-03

Abstract

The utility model relates to a low-voltage distribution protection device, which comprises a plastic shell, a low-voltage switch assembly, a main loop and a control loop, wherein the low-voltage switch assembly comprises a main contact fixed in the plastic shell, a hook movably connected in the plastic shell, a tripping spring fixed in the plastic shell, an overcurrent release, a thermal release, an undervoltage release and a shunt release fixed in the plastic shell; the main contact is arranged on a main loop, the overcurrent release and the thermal release are connected in series on the main loop, and the undervoltage release and the shunt release are connected on a control loop; the main loop comprises a copper bar fixed in the plastic shell and a cable connected with the copper bar, and a temperature sensing wire is arranged in the cable. The low-voltage distribution protection device adds the overtemperature signal in the low-voltage switch protection tripping criterion, not only has the basic function of low-voltage switch protection, but also can prevent the cable burning accident caused by the fact that the cable heating switch does not trip.

Description

Low-voltage distribution protection device

Technical Field

The utility model relates to a low pressure distribution protection device, in particular to 400V low pressure distribution switch subassembly and supporting protection device of cable.

Background

In a low-voltage distribution system, a cable is often heated or burned, and a low-voltage switch matched with the cable cannot be operated to trip. For analysis reasons, the criterion of tripping protection of the low-voltage switch is that the low-voltage switch can trip protection only when two conditions of a current setting value and a current duration are simultaneously met or an undervoltage condition is met. In actual working conditions, poor contact or arcing of the interphase cable cannot meet the protection tripping condition of the low-voltage switch, so that the cable generates heat seriously or burns.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is how to overcome prior art's above-mentioned defect, at alternate cable contact failure or arcing, and unsatisfied low voltage switch protection tripping operation condition under, can carry out the low voltage distribution protection device of tripping operation.

In order to solve the technical problem, the low-voltage distribution protection device comprises a plastic shell, a low-voltage switch assembly arranged in the plastic shell, a main loop and a control loop, wherein the main loop and the control loop are connected with elements of the low-voltage switch assembly; the main contact is arranged on a main loop, the overcurrent release and the thermal release are connected in series on the main loop, and the undervoltage release and the shunt release are connected on a control loop; the main loop comprises a copper bar fixed in the plastic shell and a cable connected with the copper bar, and a temperature sensing wire is arranged in the cable. By the design, each release is used for driving the hook to move upwards and separate, the release spring is released to drive the main contact to open, and then the main loop current is switched on and off. The temperature sensing wire is arranged in the power cable and used for remotely transmitting signals when the cable generates heat so as to enable the main contact of the low-voltage switch to trip.

Preferably, the control circuit comprises a first control line and a second control line, the undervoltage release is connected to the first control line, the shunt release is connected to the second control line, and the second control line is provided with a shunt button connected in parallel with the temperature sensing line. The temperature sensing line comprises two elastic steel wires, and the elastic steel wires are wrapped with a layer of heat-sensitive material layer. According to the design, the thermosensitive material layer is made of an insulating material which is heated to be molten, under the normal condition, the two elastic steel wires are insulated, when the ambient temperature rises to a preset value, the thermosensitive material layer is heated to be molten, the two elastic steel wires are in contact with each other to form a short circuit, and a signal is remotely transmitted, so that the shunt release acts, and the main contact trips.

Preferably, the hook comprises a hook arm and a lifting arm, and one end of the hook arm is hinged in the plastic shell. And lifting armatures are arranged between the overcurrent release and the shunt release and the lifting arms. By the design, when the main loop is short-circuited or seriously overloaded, the overcurrent release attracts and lifts the armature through short time delay, the lifting armature rotates to push the hook to deflect upwards to move and release the release spring, and the main contact acts to trip under the action of the release spring; when the opening button is started or the temperature sensing wire is short-circuited, the shunt release attracts and lifts the armature, the lifting armature pushes the hook to move upwards to release the release spring, and the main contact acts to trip under the action of the release spring.

Preferably, the thermal release comprises a resistance wire and a bimetallic strip. By the design, when the main loop is overloaded for a long time, the resistance wire heats, the bimetallic strip is deformed and bent, namely, the thermal tripping action is performed, the hook moves upwards to release the tripping spring, and the main contact operates to trip under the action of the tripping spring; when the main circuit is under voltage or under voltage, the suction force of the under-voltage release is insufficient, the hook moves upwards to release the release spring, and the main contact acts to trip under the action of the release spring.

When the main loop is overloaded for a long time, the resistance wire heats, so that the bimetallic strip deforms and bends, namely, the thermal tripping action is realized; when the main loop is short-circuited or seriously overloaded, the overcurrent release acts; when the main circuit is under voltage loss or under voltage, the suction force of the under-voltage release is insufficient to release the hook, the hook can move upwards to release the release spring under the three conditions, and the main contact acts to trip under the action of the release spring. When the cable generates heat and the situation does not exist, after the ambient temperature of the cable rises to a preset value, two elastic steel wires arranged in the temperature sensing wire of the cable are in short circuit due to the melting of the heat-sensitive material layer, and signals are transmitted to the low-voltage switch assembly remotely, so that the shunt release acts, the low-voltage switch trips, and the cable heating and burning accidents are avoided.

The utility model relates to a low pressure distribution protection device is through the configuration optimization design to increase the temperature sensing line in the cable, increase overtemperature prote signal in low-voltage switch protection tripping operation criterion, not only possess the basic function of low-voltage switch protection, can also prevent that the cable heating switch does not trip and the emergence of the cable burning accident that leads to.

Drawings

The low-voltage distribution protection device of the present invention is further described with reference to the accompanying drawings:

FIG. 1 is a schematic plan view of the low voltage distribution protection device;

fig. 2 is a schematic cross-sectional view of the temperature sensing line of the low-voltage distribution protection device.

In the figure:

1-plastic shell;

2-a low voltage switching assembly; 21-main contact, 22-hook, 23-trip spring, 24-overcurrent trip, 25-thermal trip, 26-undervoltage trip and 27-shunt trip; 221-hook arm, 222-lifting arm, 223-lifting armature, 251-resistance wire, 252-bimetallic strip;

3-a main loop; 31-temperature sensing line; 311-elastic steel wire, 312-heat sensitive material layer;

4-a control loop; 41-first control line, 42-second control line, 43-opening button.

Detailed Description

As shown in fig. 1 and 2, the low-voltage distribution protection device includes a plastic casing 1, a low-voltage switch assembly 2 installed in the plastic casing 1, a main circuit 3 and a control circuit 4 connected to components of the low-voltage switch assembly 2, wherein the low-voltage switch assembly 2 includes a main contact 21 fixed in the plastic casing 1, a hook 22 movably connected in the plastic casing 1, a trip spring 23 fixed in the plastic casing 1, an overcurrent trip 24, a thermal trip 25, an undervoltage trip 26, and a shunt trip 27 fixed in the plastic casing 1; the main contact 21 is arranged on the main loop 3, the overcurrent release 24 and the thermal release 25 are connected in series on the main loop 3, and the undervoltage release 26 and the shunt release 27 are connected on the control loop 4; the main loop 3 comprises a copper bar fixed in the plastic shell 1 and a cable connected with the copper bar, and a temperature sensing wire 31 is arranged in the cable. Each release is used for driving the hook to move upwards and separate, the release spring is released to drive the main contact to open, and then the main loop current is switched on and off. The temperature sensing wire is arranged in the cable and used for remotely transmitting signals when the cable generates heat so as to enable the main contact of the low-voltage switch to trip.

The control loop 4 comprises a first control line 41 and a second control line 42, the undervoltage release 26 is connected to the first control line 41, the shunt release 27 is connected to the second control line 42, and the second control line 42 is provided with a tripping button 43 connected in parallel with the temperature sensing line 31. The temperature sensing line 31 comprises two elastic steel wires 311, and a layer of heat sensitive material layer 312 is wrapped outside each of the two elastic steel wires 311. The thermosensitive material layer is made of an insulating material which is heated to be molten, under normal conditions, the two elastic steel wires are insulated, when the ambient temperature rises to a preset value, the thermosensitive material layer is heated to be molten, the two elastic steel wires are in contact with each other to be short-circuited, and signals are transmitted remotely, so that the shunt release acts, and the main contact trips.

The hook 22 includes a hook arm 221 and a lifting arm 222, and one end of the hook arm 221 is hinged in the plastic housing 1. A lifting armature 223 is arranged between the overcurrent release 24 and shunt release 27 and the lifting arm 222. When the main loop is in short circuit or is seriously overloaded, the overcurrent release attracts and lifts the armature through short time delay, the lifting armature rotates to push the hook to deflect upwards to move and release the release spring, and the main contact acts to trip under the action of the release spring; when the opening button is started or the temperature sensing wire is short-circuited, the shunt release attracts and lifts the armature, the lifting armature pushes the hook to move upwards to release the release spring, and the main contact acts to trip under the action of the release spring.

The thermal trip 25 includes a resistance wire 251 and a bimetal 252. When the main loop is overloaded for a long time, the resistance wire heats to enable the bimetallic strip to deform and bend, namely, the thermal tripping action is taken, so that the hook moves upwards to release the tripping spring, and the main contact acts to trip under the action of the tripping spring; when the main circuit is under voltage or under voltage, the suction force of the under-voltage release is insufficient, the hook moves upwards to release the release spring, and the main contact acts to trip under the action of the release spring.

This low pressure distribution protection device passes through configuration optimization design to increase the temperature sensing line in the cable, increase overtemperature prote signal in low-voltage switch protection tripping operation criterion, not only possess the basic function of low-voltage switch protection, can also prevent the emergence of cable burning accident that the cable heating switch does not trip and lead to.

The above embodiments are intended to be illustrative of the manner in which the invention may be made and used by persons skilled in the art, and modifications to the above embodiments will be apparent to those skilled in the art, and it is therefore intended that the invention, including but not limited to the above embodiments, be limited to any methods, processes and products consistent with the principles and novel and inventive features disclosed herein, and which are to be interpreted as illustrative and not in a limiting sense.

Claims

1. A low-voltage distribution protection device is characterized in that: comprises a plastic shell (1), a low-voltage switch component (2) arranged in the plastic shell (1), a main loop (3) and a control loop (4) which are connected with the components of the low-voltage switch component (2), wherein,

the low-voltage switch assembly (2) comprises a main contact (21) fixed in the plastic shell (1), a hook (22) movably connected in the plastic shell (1), a tripping spring (23) fixed in the plastic shell (1), an overcurrent tripper (24), a thermal tripper (25), an undervoltage tripper (26) and a shunt tripper (27) fixed in the plastic shell (1);

the main contact (21) is arranged on the main loop (3), the overcurrent release (24) and the thermal release (25) are connected in series on the main loop (3), and the undervoltage release (26) and the shunt release (27) are connected on the control loop (4);

the main loop (3) comprises a copper bar fixed in the plastic shell (1) and a cable connected with the copper bar, and a temperature sensing wire (31) is arranged in the cable.

2. The low voltage power distribution protection device of claim 1, wherein: the control circuit (4) comprises a first control line (41) and a second control line (42), the undervoltage tripper (26) is connected to the first control line (41), the shunt tripper (27) is connected to the second control line (42), and a shunt switch button (43) connected with the temperature sensing line (31) in parallel is arranged on the second control line (42).

3. A low voltage power distribution protection device according to claim 2, wherein: the temperature sensing line (31) comprises two elastic steel wires (311), and a layer of heat-sensitive material layer (312) is wrapped outside each elastic steel wire (311).

4. The low voltage power distribution protection device of claim 1, wherein: the hook (22) comprises a hook arm (221) and a lifting arm (222), and one end of the hook arm (221) is hinged in the plastic shell (1).

5. The low voltage power distribution protection device of claim 4, wherein: and lifting armatures (223) are arranged between the overcurrent release (24) and the shunt release (27) and the lifting arms (222).

6. The low voltage power distribution protection device of claim 5, wherein: the thermal trip (25) comprises a resistance wire (251) and a bimetallic strip (252).