CN214174519U

CN214174519U - Detection switching circuit and device

Info

Publication number: CN214174519U
Application number: CN202023039661.5U
Authority: CN
Inventors: 董子铭; 王刚; 王飞
Original assignee: Shenzhen Invt Electric Co Ltd
Current assignee: Shenzhen Invt Electric Co Ltd
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2021-09-10
Anticipated expiration: 2030-12-16

Abstract

The application discloses detect switching circuit and device belongs to electronic circuit technical field. The detection switching circuit comprises a switch K11, a switch K21, a connecting terminal, a switch K31 and a switch K41. The switch K11 is connected between the three-phase alternating current and the ac input of the device. The switch K21 is connected between the ac output of the device and the motor M of the device. The switch K31 is connected between the AC input end and the connection terminal of the equipment; the switch K41 is connected between the ac output terminal and the connection terminal of the device. When the switch K11 and the switch K21 are closed and the switch K31 and the switch K41 are opened, the detection switching circuit is used for performance detection. When the switch K31 and the switch K41 are closed and the switch K11 and the switch K21 are disconnected, the detection switching circuit is used for insulation resistance detection. Through the detection switching circuit and the detection switching device, equipment can be switched between performance detection and insulation resistance detection at any time, and therefore working efficiency can be improved.

Description

Detection switching circuit and device

Technical Field

The present disclosure relates to electronic circuits, and particularly to a detection switching circuit and a detection switching device.

Background

In the process of carrying out an environmental test on equipment such as a frequency converter, a vehicle-mounted driver, a vehicle-mounted charger and the like, performance detection and insulation resistance detection are required.

In the related art, due to the fact that the performance detection mode and the insulation resistance detection mode are different, the test platform needs to be repeatedly built and the detection needs to be respectively carried out in the detection process, and therefore working efficiency is low.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a detection switching circuit and a detection switching device, when the detection switching circuit and the detection switching device are used for carrying out environment tests on equipment, random switching can be carried out between performance detection and insulation resistance detection, and the working efficiency is high. The technical scheme is as follows:

in a first aspect, a detection switching circuit is provided, including: a switch K11, a switch K21, a connection terminal, a switch K31, and a switch K41;

a first end of the switch K11 is connected with three-phase alternating current, and a second end of the switch K11 is connected with an alternating current input end of equipment; a first end of the switch K21 is connected with an alternating current output end of the equipment, and a second end of the switch K21 is connected with a motor M of the equipment;

a first terminal of the switch K31 is connected to a second terminal of the switch K11, and a second terminal of the switch K31 is connected to the connection terminal; a first terminal of the switch K41 is connected to a first terminal of the switch K21, and a second terminal of the switch K41 is connected to the connection terminal;

wherein, when the switch K11 and the switch K21 are closed and the switch K31 and the switch K41 are opened, the detection switching circuit is used for performance detection; when the switch K31 and the switch K41 are closed and the switch K11 and the switch K21 are disconnected, the detection switching circuit is used for insulation resistance detection.

In the present application, when the switch K11 and the switch K21 are closed and the switch K31 and the switch K41 are open, the device can perform performance detection by detecting the switching circuit. When the switch K11 is disconnected from the switch K21 and the switches K31 and K41 are closed, the device can perform insulation resistance detection by detecting the switching circuit. Through the detection switching circuit, equipment can be switched between performance detection and insulation resistance detection at any time, and therefore working efficiency can be improved.

Optionally, the detection switching circuit further includes: a control circuit;

the control circuit is respectively connected with the switch K11, the switch K21, the switch K31 and the switch K41;

wherein the control circuit controls the switch K11 and the switch K21 to be closed and controls the switch K31 and the switch K41 to be open; alternatively, the control circuit controls the switch K11 and the switch K21 to be opened, and controls the switch K31 and the switch K41 to be closed.

Optionally, the control circuit comprises: switch S11, coil L1, coil L2, switch S21, coil L3, and coil L4;

a first end of the switch S11 is connected with a live line L;

a first end of the coil L1 is connected with a second end of the switch S11, a second end of the coil L1 is connected with a neutral wire N, so that when the switch S11 is closed, the coil L1 is electrified; when the coil L1 is electrified, the switch K11 is closed;

the coil L2 is connected in parallel with the coil L1, such that when the switch S11 is closed, the coil L2 is energized; when the coil L2 is electrified, the switch K21 is closed;

a first terminal of the switch S21 is connected to the live line L;

a first end of the coil L3 is connected with a second end of the switch S21, a second end of the coil L3 is connected with the neutral wire N, so that when the switch S21 is closed, the coil L3 is electrified; when the coil L3 is electrified, the switch K31 is closed;

the coil L4 is connected in parallel with the coil L3, such that when the switch S21 is closed, the coil L4 is energized; when the coil L4 is energized, the switch K41 is closed.

Optionally, the control circuit further comprises: a performance test button SB1, the performance test button SB1 including the switch S11 and a switch S12, the switch S11 being a normally open contact of the performance test button SB1, the switch S12 being a normally closed contact of the performance test button SB 1;

the switch S12 is in series with the switch S21 such that when the switch S21 is closed and the switch S12 is closed, the coil L3 and the coil L4 are energized.

Optionally, the control circuit further comprises: an insulation resistance detection button SB2, the insulation resistance detection button SB2 including the switch S21 and a switch S22, the switch S21 being a normally open contact of the insulation resistance detection button SB2, the switch S22 being a normally closed contact of the insulation resistance detection button SB 2;

the switch S22 is in series with the switch S11 such that when the switch S11 is closed and the switch S22 is closed, the coil L1 and the coil L2 are energized.

Optionally, the detection switching circuit further includes: a first ac contactor KM1 and a second ac contactor KM 2;

the first ac contactor KM1 includes the switch K11, the switch K12, the switch K13, and the coil L1; the switch K11 is a normally open main contact of the first alternating current contactor KM1, the switch K12 is a normally open auxiliary contact of the first alternating current contactor KM1, and the switch K13 is a normally closed auxiliary contact of the first alternating current contactor KM 1;

the second ac contactor KM2 includes the switch K21, the switch K22, the switch K23, and the coil L2; the switch K21 is a normally open main contact of the second ac contactor KM2, the switch K22 is a normally open auxiliary contact of the second ac contactor KM2, and the switch K23 is a normally closed auxiliary contact of the second ac contactor KM 2;

the switch K13 is connected in series with the switch S21;

the switch K23 is in series with the switch K13 such that when the switch S21 is closed and the switch K13 and the switch K23 are closed, the coil L3 and the coil L4 are energized;

a first terminal of the switch K12 is connected with a first terminal of the switch S11;

the first terminal of the switch K22 is connected to the second terminal of the switch K12, and the second terminal of the switch K22 is connected to the second terminal of the switch S11.

Optionally, the detection switching circuit further includes: a third ac contactor KM3 and a fourth ac contactor KM 4;

the third ac contactor KM3 includes the switch K31, the switch K32, the switch K33, and the coil L3; the switch K31 is a normally open main contact of the third ac contactor KM3, the switch K32 is a normally open auxiliary contact of the third ac contactor KM3, and the switch K33 is a normally closed auxiliary contact of the third ac contactor KM 3;

the fourth ac contactor KM4 includes the switch K41, the switch K42, the switch K43, and the coil L4; the switch K41 is a normally open main contact of the fourth ac contactor KM4, the switch K42 is a normally open auxiliary contact of the fourth ac contactor KM4, and the switch K43 is a normally closed auxiliary contact of the fourth ac contactor KM 4;

the switch K33 is connected in series with the switch S11;

the switch K43 is in series with the switch K33 such that when the switch S11 is closed and the switch K33 and the switch K43 are closed, the coil L1 and the coil L2 are energized;

a first terminal of the switch K32 is connected with a first terminal of the switch S21;

the first terminal of the switch K42 is connected to the second terminal of the switch K32, and the second terminal of the switch K42 is connected to the second terminal of the switch S21.

Optionally, the detection switching circuit further includes: a circuit breaker QS;

the circuit breaker QS has a normally open main contact QS11 and a normally closed auxiliary contact QS12, a first end of the normally open main contact QS11 is connected with the three-phase alternating current, and a second end of the normally open main contact QS11 is connected with a first end of the switch K11; the normally closed auxiliary contact QS12 is connected in series with the switch S21.

Optionally, the control circuit further comprises: lamp H1 and lamp H2;

the lamp H1 is connected in series with the switch S11;

the lamp H2 is connected in series with the switch S21.

In a second aspect, there is provided a detection switching apparatus comprising the detection switching circuit as described in the first aspect above.

It is understood that the beneficial effects of the second aspect can be referred to the related description of the first aspect, and are not described herein again.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a first detection switching circuit provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a first control circuit provided in an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a performance testing button according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of an insulation resistance detection button according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a second control circuit provided in an embodiment of the present application;

fig. 6 is a schematic structural diagram of a first ac contactor according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a third control circuit provided in the embodiment of the present application;

fig. 8 is a schematic structural diagram of a circuit breaker according to an embodiment of the present disclosure;

fig. 9 is a schematic structural diagram of a second detection switching circuit provided in an embodiment of the present application;

FIG. 10 is a schematic structural diagram of a fourth control circuit provided in the embodiments of the present application;

fig. 11 is a schematic structural diagram of a switch S3 according to an embodiment of the present disclosure;

fig. 12 is a schematic structural diagram of a third detection switching circuit according to an embodiment of the present application.

Wherein, the meanings represented by the reference numerals of the figures are respectively as follows:

10. detecting a switching circuit;

112. a connection terminal;

120. a control circuit.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

It should be understood that reference to "a plurality" in this application means two or more. In the description of the present application, "/" means "or" unless otherwise stated, for example, a/B may mean a or B; "and/or" herein is only an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, for the convenience of clearly describing the technical solutions of the present application, the terms "first", "second", and the like are used to distinguish the same items or similar items having substantially the same functions and actions. Those skilled in the art will appreciate that the terms "first," "second," etc. do not denote any order or quantity, nor do the terms "first," "second," etc. denote any order or importance.

Before explaining the embodiments of the present application in detail, an application scenario of the embodiments of the present application will be described.

Devices such as an inverter, a vehicle-mounted driver, and a vehicle-mounted charger (hereinafter, collectively referred to as devices) need to be energized by three-phase ac. The apparatus has an ac input, an ac output, and a motor. A circuit configuration may be connected between the ac input and the ac output. The ac output terminal may be connected to the motor to output ac power to the motor. The AC input end and the AC output end of the device are strong current ends.

The apparatus generally requires that environmental tests be conducted in a temperature test chamber. The environmental test comprises performance detection and insulation resistance detection. When the performance of the equipment is detected, the equipment needs to be electrified to work, so that the working performance of the equipment in different temperature environments is detected. When the insulation resistance of the device is detected, all strong current ends of the device need to be short-circuited, and the insulation impedance of the strong current ends to the ground needs to be measured. Therefore, the performance detection and the insulation resistance detection are different in wiring manner. In the related art, the test platform needs to be repeatedly built and the detection needs to be respectively carried out in the detection process, so that the working efficiency is low.

Therefore, the embodiment of the application provides a detection switching circuit and a detection switching device, and when the detection switching circuit and the detection switching device are used for carrying out an environmental test on the equipment, the performance detection and the insulation resistance detection can be switched at will.

The detection switching circuit provided in the embodiments of the present application is explained in detail below. In embodiments of the present application, the connection between two electronic devices includes a wired connection or a wireless connection. Here, the wired connection means that two electronic devices are connected by a wire, thereby performing transmission of an electric signal. Here, the wireless connection means that two electronic devices are not connected by a wire, but can transmit signals. The wireless connection may be, for example, a connection between a primary coil and a secondary coil of a transformer, or a connection between an electromagnet and an armature of an electromagnetic relay.

Fig. 1 is a schematic structural diagram of a detection switching circuit according to an embodiment of the present disclosure. Referring to fig. 1, the detection switching circuit 10 may include a switch K11, a switch K21, a connection terminal 112, a switch K31, and a switch K41.

In the drawings of the embodiments of the present application, R, S and T represent different phases of an ac input terminal of a device requiring performance detection and insulation resistance detection, U, V and W represent different phases of an ac output terminal of the device, and M represents a motor of the device. L1, L2, and L3 represent the first, second, and third phases of the three-phase alternating current, respectively. PE represents a ground line for connection to the ground terminal of the device.

The switch K11 has a first terminal and a second terminal. When the switch K11 is closed, the first terminal and the second terminal of the switch K11 are connected, and otherwise, the switch K11 is disconnected. The switch K11 is connected between the three-phase alternating current and the alternating current input of the device. In other words, a first terminal of the switch K11 is connected to the three-phase ac power, and a second terminal of the switch K11 is connected to the ac input of the device. The switch K11 may include three simultaneously acting secondary switches connected between the L1 of three-phase alternating current and the R phase of the ac input of the device, between the L2 of three-phase alternating current and the S phase of the ac input of the device, and between the L3 of three-phase alternating current and the T phase of the ac input of the device, respectively. The switch K11 can be used to open and close a circuit between the three-phase alternating current and the ac input of the device. When switch K11 is closed, three-phase ac current flows through switch K11 to the ac input of the device. Conversely, when the switch K11 is open, the ac input of the device cannot communicate with three-phase ac power.

The switch K21 has a first terminal and a second terminal. When the switch K21 is closed, the first terminal and the second terminal of the switch K21 are connected, and otherwise, the switch K21 is disconnected. The switch K21 is connected between the ac output of the device and the motor M of the device. In other words, the first terminal of the switch K21 is connected to the ac output terminal of the device, and the second terminal of the switch K21 is connected to the motor M of the device. The switch K21 may also include three simultaneously acting secondary switches connected between the U phase of the ac output of the device and the motor, between the V phase of the ac output of the device and the motor, and between the W phase of the ac output of the device and the motor, respectively. The switch K21 can be used to open and close the circuit between the ac output of the device and the motor. When the switch K21 is closed, ac power at the ac output of the device can flow to the motor through the switch K21. Conversely, when the switch K21 is open, the ac output of the device is not connected to the motor.

The connection terminal 112 is a terminal for connecting different wires together. The connection terminal 112 may be a conductive copper sheet. In the embodiment of the present application, the connection terminal 112 may be a strong electric terminal. The strong electric terminal here is a terminal having a quasi-withstand voltage of more than 250V (volts).

The switch K31 has a first terminal and a second terminal. When the switch K31 is closed, the first terminal and the second terminal of the switch K31 are connected, and otherwise, the switch K31 is disconnected. The switch K31 is connected between the second terminal of the switch K11 and the connection terminal 112, i.e., between the ac input terminal of the device and the connection terminal 112. In other words, the first terminal of the switch K31 is connected to the second terminal of the switch K11, and the second terminal of the switch K31 is connected to the connection terminal 112. The switch K31 may also include three secondary switches that operate simultaneously. The switch K31 may be used to open and close a circuit between the ac input of the device and the connection terminal 112. When the switch K31 is closed, conduction is established between the ac input of the device and the connection terminal 112. When the switch K31 is open, the ac input of the device is disconnected from the connection terminal 112.

The switch K41 has a first terminal and a second terminal. When the switch K41 is closed, the first terminal and the second terminal of the switch K41 are connected, and otherwise, the switch K41 is disconnected. The switch K41 is connected between the first end of the switch K21 and the connection terminal 112, i.e., between the ac output terminal of the apparatus and the connection terminal 112. In other words, the first terminal of the switch K41 is connected to the first terminal of the switch K21, and the second terminal of the switch K41 is connected to the connection terminal. The switch K41 may also include three secondary switches that operate simultaneously. The switch K41 may be used to open and close a circuit between the ac output of the device and the connection terminal 112. When the switch K41 is closed, conduction is established between the ac output of the device and the connection terminal 112. When the switch K41 is open, the ac output of the device is disconnected from the connection terminal 112.

When the detection switching circuit 10 provided in the embodiment of the application operates, if the switch K11 and the switch K21 are closed and the switch K31 and the switch K41 are opened, the three-phase alternating current output by the L1, the L2 and the L3 may sequentially pass through the switch K11, the alternating current input end of the device, the alternating current output end of the device and the switch K21 to reach the motor, so that the motor is powered on to operate. At this time, the performance of the device can be detected. When the switch K11 and the switch K21 are opened and the switch K31 and the switch K41 are closed, three-phase alternating current cannot flow into the device, and the alternating current input terminal and the alternating current output terminal of the device are short-circuited to the connection terminal 112. At this time, the insulation resistance of the device may be detected, and specifically, an external insulation resistance detector may be used to detect the resistance of the connection terminal 112 with respect to the ground line, that is, the insulation resistance between the strong current terminal of the device and the ground line may be measured.

In other words, when the switch K11 and the switch K21 are closed and the switch K31 and the switch K41 are open, the apparatus satisfies the performance detection condition. When the switch K11 is disconnected from the switch K21, and the switches K31 and K41 are closed, the apparatus satisfies the insulation resistance detection condition. Through detecting switching circuit 10, this equipment can detect and switch at will between the insulation resistance detects at performance, need not repeatedly build test platform, has promoted this equipment and has carried out environmental test's work efficiency.

In the embodiment of the present application, the detection switching circuit 10 may further include a control circuit 120. The control circuit 120 is connected to the switch K11, the switch K21, the switch K31, and the switch K41, respectively, to control opening or closing of the switch K11, the switch K21, the switch K31, and the switch K41. Alternatively, the control circuit 120 may control the switch K11 and the switch K21 to be closed and the switch K31 and the switch K41 to be open. Alternatively, the control circuit 120 may control the switch K11 and the switch K21 to be opened, and the switch K31 and the switch K41 to be closed.

In the embodiment of the present application, the circuit structure of the control circuit 120 may be as shown in fig. 2. The control circuit 120 includes a switch S11, a coil L1, a coil L2, a switch S21, a coil L3, and a coil L4.

The switch S11 has a first terminal and a second terminal. When the switch S11 is closed, the first terminal and the second terminal of the switch S11 are turned on, and vice versa. A first terminal of the switch S11 is connected to the live line L. Coil L1 may be an energizable coil wound around a core. Coil L1 has a first end and a second end. A first end of coil L1 is connected to the second end of switch S11, and a second end of coil L1 is connected to neutral wire N. When the switch S11 is closed, the coil L1 is connected between the live line L and the neutral line N, and ac power is supplied to the coil L1. Conversely, when switch S11 is open, coil L1 is disconnected from hot line L, and no current flows through coil L1. Coil L1 may be connected to switch K11 by electromagnetic induction so that when coil L1 is energized, switch K11 is closed.

Coil L2 may be an energizable coil wound around a core. Coil L2 is connected in parallel with coil L1. When the switch S11 is closed, the coil L2 is connected between the live line L and the neutral line N, and ac power is supplied to the coil L2. Conversely, when switch S11 is open, coil L2 is disconnected from hot line L, and no current flows through coil L2. Coil L2 may be connected to switch K21 by electromagnetic induction so that when coil L2 is energized, switch K21 is closed.

The switch S21 has a first terminal and a second terminal. When the switch S21 is closed, the first terminal and the second terminal of the switch S21 are turned on, and vice versa. A first terminal of the switch S21 is connected to the live line L. Coil L3 may be an energizable coil wound around a core. Coil L3 has a first end and a second end. A first end of coil L3 is connected to the second end of switch S21, and a second end of coil L3 is connected to neutral wire N. When the switch S21 is closed, the coil L3 is connected between the live line L and the neutral line N, and ac power is supplied to the coil L3. Conversely, when switch S21 is open, coil L3 is disconnected from hot line L, and no current flows through coil L3. Coil L3 may be connected to switch K31 by electromagnetic induction so that when coil L3 is energized, switch K31 is closed.

Coil L4 may be an energizable coil wound around a core. Coil L4 is connected in parallel with coil L3. When the switch S21 is closed, the coil L4 is connected between the live line L and the neutral line N, and ac power is supplied to the coil L4. Conversely, when switch S21 is open, coil L4 is disconnected from hot line L, and no current flows through coil L4. Coil L4 may be connected to switch K41 by electromagnetic induction so that when coil L4 is energized, switch K41 is closed.

When the switch S11 is controlled to be closed and the switch S21 is opened, the switch K11 and the switch K21 are controlled to be closed, and the switch K31 and the switch K41 are controlled to be opened, so that the device meets the performance detection condition. On the contrary, when the control switch S11 is opened and the switch S21 is closed, the switch K11 and the switch K21 are opened, and the switch K31 and the switch K41 are closed, so that the device meets the insulation resistance detection condition. The switch S11 and the switch S21 can realize the switching of different detection modes of the device.

In the embodiment of the present application, the control circuit 120 may further include a performance detection button SB1 and an insulation resistance detection button SB 2. Referring to fig. 3, the performance detection button SB1 includes the switch S11 and the switch S12 described above. Wherein, the switch S11 is the normally open contact of the performance detection button SB 1. The switch S12 is a normally closed contact of the performance detection button SB 1. Referring to fig. 4, the insulation resistance detection button SB2 includes the switch S21 and the switch S22 described above. The switch S21 is a normally open contact of the insulation resistance detection button SB 2. Switch S22 is a normally closed contact of the insulation resistance detection button SB 2.

Fig. 3 shows the structure of the performance detection button SB 1. The performance testing button SB1 may be composed of a spring, a switch S11, a switch S12, and a button B1. When the performance detecting button SB1 is not operated, the switch S12 is in the closed state and the switch S11 is in the open state due to the spring tension. When the button B1 of the performance detecting button SB1 is pressed, the spring is expanded by the pressing force, the switch S11 is closed, and the switch S12 is opened. The normally open contact of the performance detection button SB1 means the switch S11 that is in the open state when the performance detection button SB1 is not operated. The normally closed contact of the performance testing button SB1 means the switch S12 in the closed state when the performance testing button SB1 is not operated.

Fig. 4 shows the structure of the insulation resistance detection button SB 2. The insulation resistance detection button SB2 may be composed of a spring, a switch S21, a switch S22, and a button B2. When the insulation resistance detection button SB2 is not operated, the switch S22 is in the closed state and the switch S21 is in the open state due to the spring tension. When the button B2 of the insulation resistance detection button SB2 is pressed, the spring is expanded by the pressing force, the switch S21 is closed, and the switch S22 is opened. The normally open contact of the insulation resistance detection button SB2 means the switch S21 that is in the open state when the insulation resistance detection button SB2 is not operated. The normally closed contact of the insulation resistance detection button SB2 means the switch S22 in the closed state when the insulation resistance detection button SB2 is not operated.

Referring to fig. 5, the connection relationship of the switch S12 of the performance check button SB1 and the switch S22 of the insulation resistance check button SB2 in the control circuit 120 is shown. The switch S22 is connected in series with the switch S11, so that the switch S22 and the switch S11 control the on/off of the circuit where the coil L1 and the coil L2 are located. When the switch S11 is closed and the switch S22 is closed, the coil L1 is connected between the live wire L and the zero wire N, alternating current is introduced into the coil L1, and the switch K11 is controlled to be closed. Similarly, when the switch S11 is closed and the switch S22 is closed, the coil L2 is connected between the live line L and the neutral line N, the coil L2 is supplied with alternating current, and the switch K21 is controlled to be closed. Coil L1 and coil L2 are both disconnected from hot line L if at least one of switch S11 and switch S22 is open.

The switch S12 is connected in series with the switch S21, so that the switch S12 and the switch S21 control the on/off of the circuit in which the coil L3 and the coil L4 are located. When the switch S21 is closed and the switch S12 is closed, the coil L3 is connected between the live wire L and the zero wire N, alternating current is introduced into the coil L3, and the switch K31 is controlled to be closed. Similarly, when the switch S21 is closed and the switch S12 is closed, the coil L4 is connected between the live line L and the neutral line N, the coil L4 is supplied with alternating current, and the switch K41 is controlled to be closed. Coil L3 and coil L4 are both disconnected from hot line L if at least one of switch S21 and switch S12 is open.

As described above, the switch S11 is the normally open contact of the performance detecting button SB 1. The switch S12 is a normally closed contact of the performance detection button SB 1. Switch S21 is the normally open contact of insulation resistance sensing button SB 2. Switch S22 is a normally closed contact of the insulation resistance detection button SB 2. Thus, when only the button B1 of the performance detection button SB1 is pressed, the switch S11 can be closed and the switch S12 can be opened. At this time, since the switch S12 is opened, it can be ensured that the coil L3 and the coil L4 are disconnected from the live line L, that is, the switch K31 and the switch K41 cannot be closed. Meanwhile, since the insulation resistance detection button SB2 is not operated, the switch S21 is opened and the switch S22 is closed. When the switch S11 is closed and the switch S22 is closed, the coil L1 and the coil L2 are respectively connected between the live wire L and the neutral wire N, the coil L1 and the coil L2 are electrified, the switch K11 and the switch K21 are closed, and the device meets the performance detection condition.

After the performance test button SB1 is restored, i.e., the switch S11 is restored to the open state, and the switch S12 is restored to the closed state, the insulation resistance test button SB2 may be pressed to make the device satisfy the insulation resistance test condition. When only the button B2 of the insulation resistance detection button SB2 is pressed, the switch S21 may be closed and the switch S22 may be opened. At this time, since the switch S22 is opened, it can be ensured that the coil L1 and the coil L2 are disconnected from the live line L, that is, the switch K11 and the switch K21 cannot be closed. When the switch S12 is closed and the switch S21 is closed, the coil L3 and the coil L4 are respectively connected between the live line L and the neutral line N, the coil L3 and the coil L4 are electrified, the switch K31 and the switch K41 are closed, and the device meets the insulation resistance detection condition. In the embodiment of the application, the performance detection button SB1 and the insulation resistance detection button SB2 are interlocked, so that when the coil L1 and the coil L2 are electrified, the coil L3 and the coil L4 cannot be electrified; when the coil L3 and the coil 4 are electrified, the coil L1 and the coil L2 cannot be electrified, so that the phenomenon that the switch K11, the switch K21, the switch K31 and the switch K41 are simultaneously conducted to cause accidents can be avoided.

In the embodiment of the present application, the detection switching circuit 10 may further include a first ac contactor KM1 and a second ac contactor KM 2. Referring to fig. 6, the first ac contactor KM1 includes a switch K11, a switch K12, a switch K13, and a coil L1. The switch K11 is a normally open main contact of the first alternating current contactor KM 1. The switch K12 is a normally open auxiliary contact of the first ac contactor KM 1. The switch K13 is a normally closed auxiliary contact of the first ac contactor KM 1.

Fig. 6 shows the structure of a first ac contactor KM 1. The first ac contactor KM1 may be composed of a spring, a core connected to the spring, a switch K11, a switch K12, a switch K13, and a coil L1. When the coil L1 is not energized, the iron core is under the action of the spring tension, the switch K11 is in an open state, the switch K12 is in an open state, and the switch K13 is in a closed state. After the coil L1 is electrified, the iron core and the coil L1 attract each other, the spring extends, the switch K11 is in a closed state, the switch K12 is in a closed state, and the switch K13 is in an open state. The switch K12 and the switch K13 may be connected in the control circuit 120. The normally open main contact of the first ac contactor KM1 means that the first ac contactor is in an open state when the coil L1 is not energized, and is connected to the switch K11 of the three-phase ac circuit. The normally open auxiliary contact of the first ac contactor KM1 means that it is in an open state when the coil L1 is not energized, and is connected to the switch K12 of the control circuit 120. The normally closed auxiliary contact of the first ac contactor KM1 means that it is in a closed state when the coil L1 is not energized, and is connected to the switch K13 of the control circuit 120.

The second ac contactor KM2 includes a switch K21, a switch K22, a switch K23, and a coil L2. The switch K21 is a normally open main contact of the second ac contactor KM2, the switch K22 is a normally open auxiliary contact of the second ac contactor KM2, and the switch K23 is a normally closed auxiliary contact of the second ac contactor KM 2. The second ac contactor KM2 has the same structure as the first ac contactor KM1, and thus, description thereof is omitted.

In the embodiment of the present application, the detection switching circuit 10 may further include a third ac contactor KM3 and a fourth ac contactor KM 4. The third ac contactor KM3 includes a switch K31, a switch K32, a switch K33, and a coil L3. The switch K31 is a normally open main contact of the third ac contactor KM 3. The switch K32 is a normally open auxiliary contact of the third ac contactor KM 3. The switch K33 is a normally closed auxiliary contact of the third ac contactor KM 3. The fourth ac contactor KM4 includes a switch K41, a switch K42, a switch K43, and a coil L4. The switch K41 is a normally open main contact of the fourth ac contactor KM 4. The switch K42 is a normally open auxiliary contact of the fourth ac contactor KM 4. The switch K43 is a normally closed auxiliary contact of the fourth ac contactor KM 4. The third ac contactor KM3, the fourth ac contactor KM4 and the first ac contactor KM1 have the same structure, and thus, description thereof is omitted.

Referring to fig. 7, the connection relationship of a first ac contactor KM1, a second ac contactor KM2, a third ac contactor KM3 and a fourth ac contactor KM4 in the control circuit 120 is shown. The switch K13 is connected in series with the switch S21, and the switch K23 is connected in series with the switch K13, so that the switch K13, the switch S21 and the switch K23 jointly control the on-off of a circuit where the coil L3 and the coil L4 are located. In the embodiment shown in fig. 7, a switch S12 is also connected in series on the line on which the switch K13, the switch K23 and the switch S21 are located. When the switch K13, the switch K23, the switch S21 and the switch S12 are simultaneously closed, the coil L3 and the coil L4 are respectively connected between the live line L and the zero line N, alternating current is introduced into the coil L3 and the coil L4, and the switch K31 and the switch K41 are controlled to be closed. Coil L3 and coil L4 are both disconnected from the live line L if at least one of switch K13, switch K23, switch S21 and switch S12 is open.

The switch K12 has a first terminal and a second terminal, and when the switch K12 is closed, the first terminal and the second terminal of the switch K12 are conducted. When the switch K12 is open, the switch K12 is open between the first terminal and the second terminal. A first terminal of the switch K12 is connected to a first terminal of the switch S11. Switch K22 also has a first terminal and a second terminal. When the switch K22 is closed, conduction is formed between the first terminal and the second terminal of the switch K22. When the switch K22 is open, the switch K22 is open between the first terminal and the second terminal. The first terminal of the switch K22 is connected to the second terminal of the switch K12, and the second terminal of the switch K22 is connected to the second terminal of the switch S11. In other words, the switch K12 and the switch K22 are connected in series, and the switch K12 and the switch K22 after the series connection are connected in parallel across the switch S11.

Switch K33 is connected in series with switch S11, and switch K43 is connected in series with switch K33, so that switch K33, switch S11 and switch K43 jointly control the on/off of the circuit of coil L1 and coil L2. In the embodiment shown in fig. 7, a switch S22 is also connected in series on the line on which the switch K33, the switch S11 and the switch K43 are located. When the switch K33, the switch S11, the switch K43 and the switch S22 are simultaneously closed, the coil L1 and the coil L2 are respectively connected between the live line L and the neutral line N, alternating current is introduced into the coil L1 and the coil L2, and the switch K11 and the switch K21 are controlled to be closed. Coil L1 and coil L2 are both disconnected from the live line L if at least one of switch K33, switch S11, switch K43 and switch S22 is open.

The switch K32 has a first terminal and a second terminal, and when the switch K32 is closed, the first terminal and the second terminal of the switch K32 are conducted. When the switch K32 is open, the switch K32 is open between the first terminal and the second terminal. A first terminal of the switch K32 is connected to a first terminal of the switch S21. Switch K42 also has a first terminal and a second terminal. When the switch K42 is closed, conduction is formed between the first terminal and the second terminal of the switch K42. When the switch K42 is open, the switch K42 is open between the first terminal and the second terminal. The first terminal of the switch K42 is connected to the second terminal of the switch K32, and the second terminal of the switch K42 is connected to the second terminal of the switch S21. In other words, the switch K32 and the switch K42 are connected in series, and the switch K32 and the switch K42 after the series connection are connected in parallel across the switch S21.

As described above, the switch K33 is the normally closed auxiliary contact of the third ac contactor KM 3. The switch K43 is a normally closed auxiliary contact of the fourth ac contactor KM 4. Switch S22 is a normally closed contact of the insulation resistance detection button SB 2. Switch S11 is the normally open contact of performance test button SB 1. Thus, when the button B1 of the performance detection button SB1 is pressed, the switch S11 can be closed. At this time, the coil L1 and the coil L2 are communicated with the live wire L through the switch S22, the switch S11, the switch K43 and the switch K33, the coil L1 and the coil L2 are electrified, the switch K11 and the switch K21 are closed, and the device meets performance detection conditions. Meanwhile, when the coil L1 and the coil L2 are electrified, the switch K22 is also controlled to be closed, and the switch K12 is controlled to be closed. When coil L1 and coil L2 are energized, switch K13 is also controlled to be open, and switch K23 is also controlled to be open.

The recovery performance detecting button SB1, i.e., the switch S11 recovers the open state, and the switch S12 recovers the closed state. At this time, the switch K13 returns to the closed state, and the switch K23 returns to the closed state. Thus, when the button B2 of the insulation resistance detection button SB2 is pressed, the switch S21 can be closed. At this time, the coil L3 and the coil L4 are both communicated with the live wire L through the switch S12, the switch S21, the switch K23 and the switch K13, and the coil L3 and the coil L4 are energized to close the switch K31 and the switch K41, so that the device meets the insulation resistance detection condition. Meanwhile, when the coil L3 and the coil L4 are electrified, the switch K32 is also controlled to be closed, and the switch K42 is controlled to be closed. When coil L3 and coil L4 are energized, switch K33 is also controlled to be open, and switch K43 is also controlled to be open.

In the present embodiment, the first ac contactor KM1 and the second ac contactor KM2 are interlocked with the third ac contactor KM3 and the fourth ac contactor KM 4. That is, when coil L1 and coil L2 are energized, switch K13 and switch K23 are opened, and coil L3 and coil L4 cannot be energized. Conversely, when coil L3 and coil L4 are energized, switch K33 and switch K43 are open, and coil L1 and coil L2 cannot be energized. This application embodiment can further avoid switch K11, switch K21, switch K31 and switch K41 to switch on simultaneously, causes the accident.

In the embodiment of fig. 7, the control circuit 120 further includes a switch QF, which is a master switch of the control circuit 120, and the control circuit 120 can be powered on to operate when the switch QF is closed. The switch QF includes two auxiliary switches acting simultaneously, connected to the live line L and the zero line N, respectively, and will not be described again.

In the embodiment of the present application, the detection switching circuit 10 may further include a circuit breaker QS. Referring to fig. 8, circuit breaker QS has a normally open main contact QS11 and a normally closed auxiliary contact QS 12. Fig. 8 shows the structure of the circuit breaker QS. The circuit breaker QS may be comprised of a spring, a normally open main contact QS11, a normally closed auxiliary contact QS12, and a button B3. The normally open main contact QS11 may include three secondary switches for connection in a three-phase ac circuit, respectively. A normally closed auxiliary contact QS12 may be connected in the control circuit 120. When the circuit breaker QS is not operated, the normally open main contact QS11 is in an open state and the normally closed auxiliary contact QS12 is in a closed state under the action of spring tension. When the button B3 of the circuit breaker QS is pressed, the spring is stretched by the pressing force, the normally open main contact QS11 is in a closed state, and the normally closed auxiliary contact QS12 is in an open state.

Fig. 9 shows the connection relationship of the normally open main contact QS11 of the circuit breaker QS in the detection switching circuit 10. Normally open main contact QS11 is connected between the three-phase alternating current and switch K11, i.e., normally open main contact QS11 is connected in series with switch K11. In other words, a first terminal of the normally open main contact QS11 is connected to the three-phase ac power, and a second terminal of the normally open main contact QS11 is connected to a first terminal of the switch K11. When the normally open main contact QS11 is closed simultaneously with switch K11, three-phase ac current flows through the normally open main contact QS11 and switch K11 to the ac input of the device. When the normally open main contact QS11 is disconnected from at least one of the switches K11, the ac input of the device cannot communicate with three-phase ac power. Fig. 10 shows the connection relationship of the normally closed auxiliary contact QS12 of the circuit breaker QS in the control circuit 120. A normally closed auxiliary contact QS12 is connected in series with switch S21. When switch S21 is closed and the normally closed auxiliary contact QS12 is closed, coil L3 and coil L4 are energized. In the embodiment shown in fig. 10, normally closed auxiliary contact QS12, switch S21, switch S12, switch K23 and switch K13 are connected in series. Coil L3 and coil L4 are energized when normally closed auxiliary contact QS12, switch S21, switch S12, switch K23 and switch K13 are all closed. When at least one of the normally closed auxiliary contact QS12, switch S21, switch S12, switch K23, and switch K13 is opened, coil L3 and coil L4 are not energized.

In the embodiment of the present application, when the performance of the device is detected by the detection switching circuit 10, the normally open main contact QS11 of the circuit breaker QS is necessarily in a closed state, and the normally closed auxiliary contact QS12 of the circuit breaker QS is necessarily in an open state. At this time, the coil L3 and the coil L4 cannot be energized. On the contrary, when the coil L3 and the coil L4 are energized, the normally closed auxiliary contact QS12 of the circuit breaker QS is always in a closed state, and the normally open main contact QS11 of the circuit breaker QS is always in an open state, and at this time, the three-phase alternating current cannot be input into the device. According to the embodiment of the application, the accident caused by the short circuit of the strong current end when the equipment is connected with the three-phase alternating current can be avoided.

Referring to fig. 10, in the embodiment of the present application, the control circuit 120 may further include a lamp H1 and a lamp H2. Lamp H1 is connected in series with switch S11 so that when coil L1 and coil L2 are connected to hot line L, current flows in lamp H1 and lamp H1 illuminates. In the embodiment shown in fig. 10, a switch S22, a switch S11, a switch K43, and a switch K33 are also included in series with the lamp H1. When switch S22, switch S11, switch K43 and switch K33 are all closed, coil L1 and coil L2 are in communication with live line L, coil L1 and coil L2 are energized, and lamp H1 is illuminated. In other words, the lamp H1 is a performance detection indicator lamp. When the lamp H1 emits light, it indicates that the device is being performance tested by the test switching circuit 10.

Lamp H2 is connected in series with switch S21 so that when coil L3 and coil L4 are connected to hot line L, current flows in lamp H2 and lamp H2 illuminates. In the embodiment shown in fig. 10. Also included in series with lamp H2 are a normally closed auxiliary contact QS12, switch S21, switch S12, switch K23 and switch K13. When the normally closed auxiliary contact QS12, switch S21, switch S12, switch K23 and switch K13 are all closed, coil L3 and coil L4 are energized and lamp H2 is illuminated. In other words, the lamp H2 is an insulation resistance detection indicator lamp. When the lamp H2 emits light, it indicates that the device is performing insulation resistance detection by the detection switching circuit 10.

Referring to fig. 10, in the embodiment of the present application, the control circuit 120 may further include a fuse FU and a switch S3 connected to the trunk, so that the current in the power line L must pass through the fuse FU and the switch S3 to reach the switch K33 and the switch K13. Fuse FU can be the current fuse, and when the main road electric current of live wire L was too big, fuse FU disconnection played the effect of protection circuit. Switch S3 is a normally closed switch that may be configured as shown in fig. 11. When the switch S3 is not operated, the switch S3 is closed by the spring tension. When the switch S3 is pressed, the spring is extended by the pressure, and the switch S3 is in an off state.

In the above description, the main circuit in the detection switching circuit 10 of the embodiment of the present application is described separately from the control circuit 120. The main circuit here refers to the circuit between the three-phase alternating current and the device, the connection terminal 112. The operation of the detection switch circuit 10 according to the embodiment of the present application will be fully described with reference to fig. 12. The detection switching circuit 10 shown in fig. 12 is a main circuit including the detection switching circuit 10 shown in fig. 9, the control circuit 120 shown in fig. 10, and a specific configuration of each electronic device.

Referring to fig. 12, when the device needs to perform performance detection, the circuit breaker QS may be operated first, so that the normally open main contact QS11 of the circuit breaker QS is closed, and the normally closed auxiliary contact QS12 is opened. When the normally closed auxiliary contact QS12 is opened, the branch circuit of the coil L3 and the branch circuit of the coil L4 cannot be communicated. The button B1 of the performance detection button SB1 is pressed. At this time, the current in the live line L may enter the coil L1 and the coil L2 through the fuse FU, the switch S3, the switch K33, the switch K43, the switch S11, the switch S22, and the lamp H1, and flow into the neutral line N. After the coil L1 and the coil L2 are electrified, the iron core is attracted, and the lamp H1 is lightened. At this time, the normally open main contact switch K11, the normally open auxiliary contact switch K12, and the normally closed auxiliary contact switch K13 in the first ac contactor KM1 are closed. The normally open main contact switch K21, the normally open auxiliary contact switch K22, and the normally closed auxiliary contact switch K23 in the second ac contactor KM2 are closed. The opening of the switch K13 and the switch K23 can further ensure that the coil L3 and the coil L4 are not electrified, and the switch K31 and the switch K41 are opened. The three-phase alternating current output from L1, L2, and L3 may be input to alternating current input terminals R, S and T of the apparatus and output from alternating current output terminals U, V and W of the apparatus to the motor. The motor is operated and the device is operated.

When insulation resistance detection is needed, the circuit breaker QS can be operated firstly, so that a normally open main contact QS11 of the circuit breaker QS is opened, and a normally closed auxiliary contact QS12 is closed. When the normally open main contact QS11 of the circuit breaker QS is opened, three-phase alternating current cannot be introduced into the equipment. The restorability check button SB1 presses the button B2 of the insulation resistance check button SB 2. At this time, the switch S11 and the switch S22 are opened, the coil L1 and the coil L2 cannot be supplied with alternating current, the normally open main contact switch K11, the normally open auxiliary contact switch K12 and the normally closed auxiliary contact switch K13 in the first alternating current contactor KM1 are opened. The normally open main contact switch K21, the normally open auxiliary contact switch K22, and the normally closed auxiliary contact switch K23 in the second ac contactor KM2 are open. Current in the live line L can enter the coil L3 and the coil L4 and flow into the neutral line N through the fuse FU, the switch S3, the switch K13, the switch K23, the switch S21, the switch S12, the normally closed auxiliary contact QS12 and the lamp H2. After the coil L3 and the coil L4 are electrified, the iron core is attracted, and the lamp H2 is lightened. At this time, the normally open main contact switch K31, the normally open auxiliary contact switch K32, and the normally closed auxiliary contact switch K33 in the third ac contactor KM3 are closed. The normally open main contact switch K41, the normally open auxiliary contact switch K42, and the normally closed auxiliary contact switch K43 in the fourth ac contactor KM4 are closed. The disconnection of the switch K33 and the switch K43 can further ensure that the coil L1 and the coil L2 are not electrified, and the switch K11 and the switch K21 are disconnected. At this time, the ac input terminals R, S and T of the device are connected to the connection terminal 112 via the switch K31, and the ac output terminals U, V and W of the device are connected to the connection terminal 112 via the switch K41, i.e., the ac input terminals and the ac output terminals of the device are short-circuited at the connection terminal 112. The external insulation resistance detector is used for detecting the resistance of the connecting terminal 112 relative to the ground wire, and the insulation resistance value between the strong current end and the ground wire of the equipment can be measured.

When the performance detection needs to be switched to the insulation resistance detection, the circuit breaker QS can be operated firstly, so that a normally-open main contact QS11 of the circuit breaker QS is closed, and a normally-closed auxiliary contact QS12 is opened. Then, the insulation resistance detection button SB2 is pressed. At this time, since the pressed performance detection button SB1 has not been restored, the switch S12 is turned off. Meanwhile, as the insulation resistance detection button SB2 is pressed, the switch S22 is also switched off, and the branch circuits of the coil L1 and the coil L2, and the branch circuits of the coil L3 and the branch circuits of the coil L4 are not electrified, so that short circuit caused by misoperation can be ensured. The insulation resistance detection can be performed by the restitution performance detection button SB 1.

When the insulation resistance of the device is detected, if the circuit breaker QS is operated by mistake, the normally open main contact QS11 of the circuit breaker QS is closed, and at this time, the normally closed auxiliary contact QS12 of the circuit breaker QS opens, and the circuit where the coil L3 and the coil L4 are located is opened. The detection switching circuit 10 of the embodiment of the application can ensure that the equipment does not have strong electricity access when carrying out insulation resistance detection, thereby not only eliminating the danger caused by misoperation when the insulation resistance is detected, but also eliminating the main contact adhesion possibly caused by long-term work of the alternating current contactor KM1 and the alternating current contactor KM2 and the risk of normal work of the auxiliary contacts.

The embodiment of the present application further provides a detection switching device, and the detection switching device may include the detection switching circuit in any one of the above embodiments.

In an embodiment of the present application, the detection switching device includes a detection switching circuit, and the detection switching circuit includes: switch K11, switch K21, connection terminal, switch K31, and switch K41. A first terminal of the switch K11 is connected to the three-phase AC power, and a second terminal of the switch K11 is connected to the AC input of the device. The first end of the switch K21 is connected with the AC output end of the equipment, and the second end of the switch K21 is connected with the motor M of the equipment. The first terminal of the switch K31 is connected to the second terminal of the switch K11, and the second terminal of the switch K31 is connected to the connection terminal. The first terminal of the switch K41 is connected to the first terminal of the switch K21, and the second terminal of the switch K41 is connected to the connection terminal.

When the switch K11 and the switch K21 are closed and the switch K31 and the switch K41 are opened, the detection switching circuit is used for performance detection. When the switch K31 and the switch K41 are closed and the switch K11 and the switch K21 are disconnected, the detection switching circuit is used for insulation resistance detection.

In an embodiment of the present application, the detection switching circuit further includes: a control circuit. The control circuit is respectively connected with the switch K11, the switch K21, the switch K31 and the switch K41. The control circuit controls the switch K11 and the switch K21 to be closed, and controls the switch K31 and the switch K41 to be opened; alternatively, the control circuit controls the switch K11 and the switch K21 to be open, and controls the switch K31 and the switch K41 to be closed.

In an embodiment of the present application, the control circuit includes: switch S11, coil L1, coil L2, switch S21, coil L3, and coil L4. The first end of the switch S11 is connected with the live wire L; a first end of coil L1 is connected to a second end of switch S11 and a second end of coil L1 is connected to neutral N so that coil L1 is energized when switch S11 is closed; when coil L1 is energized, switch K11 is closed. Coil L2 is connected in parallel with coil L1 so that when switch S11 is closed, coil L2 is energized; when coil L2 is energized, switch K21 is closed.

A first terminal of the switch S21 is connected to the live line L. A first end of coil L3 is connected to a second end of switch S21 and a second end of coil L3 is connected to neutral N so that coil L3 is energized when switch S21 is closed; when coil L3 is energized, switch K31 is closed. Coil L4 is connected in parallel with coil L3 so that when switch S21 is closed, coil L4 is energized; when coil L4 is energized, switch K41 is closed.

In an embodiment of the present application, the control circuit further includes: the performance test button SB1, the performance test button SB1 includes a switch S11 and a switch S12, the switch S11 is the normally open contact of the performance test button SB1, and the switch S12 is the normally closed contact of the performance test button SB 1. Switch S12 is connected in series with switch S21 such that when switch S21 is closed and switch S12 is closed, coil L3 and coil L4 are energized.

In an embodiment of the present application, the control circuit further includes: the insulation resistance detection button SB2 and the insulation resistance detection button SB2 include a switch S21 and a switch S22, the switch S21 is a normally open contact of the insulation resistance detection button SB2, and the switch S22 is a normally closed contact of the insulation resistance detection button SB 2. Switch S22 is connected in series with switch S11 such that when switch S11 is closed and switch S22 is closed, coil L1 and coil L2 are energized.

In an embodiment of the present application, the detection switching circuit further includes: a first ac contactor KM1 and a second ac contactor KM 2.

The first ac contactor KM1 includes a switch K11, a switch K12, a switch K13, and a coil L1. The switch K11 is a normally open main contact of the first ac contactor KM1, the switch K12 is a normally open auxiliary contact of the first ac contactor KM1, and the switch K13 is a normally closed auxiliary contact of the first ac contactor KM 1.

The second ac contactor KM2 includes a switch K21, a switch K22, a switch K23, and a coil L2. The switch K21 is a normally open main contact of the second ac contactor KM2, the switch K22 is a normally open auxiliary contact of the second ac contactor KM2, and the switch K23 is a normally closed auxiliary contact of the second ac contactor KM 2.

Switch K13 is connected in series with switch S21. Switch K23 is connected in series with switch K13 such that when switch S21 is closed and switch K13 and switch K23 are closed, coil L3 and coil L4 are energized.

A first terminal of the switch K12 is connected to a first terminal of the switch S11. The first terminal of the switch K22 is connected to the second terminal of the switch K12, and the second terminal of the switch K22 is connected to the second terminal of the switch S11.

In an embodiment of the present application, the detection switching circuit further includes: a third ac contactor KM3 and a fourth ac contactor KM 4.

The third ac contactor KM3 includes a switch K31, a switch K32, a switch K33, and a coil L3. The switch K31 is a normally open main contact of a third alternating current contactor KM3, the switch K32 is a normally open auxiliary contact of the third alternating current contactor KM3, and the switch K33 is a normally closed auxiliary contact of the third alternating current contactor KM 3.

The fourth ac contactor KM4 includes a switch K41, a switch K42, a switch K43, and a coil L4. The switch K41 is a normally open main contact of the fourth ac contactor KM4, the switch K42 is a normally open auxiliary contact of the fourth ac contactor KM4, and the switch K43 is a normally closed auxiliary contact of the fourth ac contactor KM 4.

The switch K33 is connected in series with the switch S11; switch K43 is connected in series with switch K33 such that when switch S11 is closed and switch K33 and switch K43 are closed, coil L1 and coil L2 are energized. A first terminal of the switch K32 is connected to a first terminal of the switch S21; the first terminal of the switch K42 is connected to the second terminal of the switch K32, and the second terminal of the switch K42 is connected to the second terminal of the switch S21.

In an embodiment of the present application, the detection switching circuit further includes: the circuit breaker QS. The circuit breaker QS has a normally open main contact QS11 and a normally closed auxiliary contact QS 12. A first end of a normally open main contact QS11 is connected to three-phase alternating current, and a second end of the normally open main contact QS11 is connected to a first end of a switch K11. A normally closed auxiliary contact QS12 is connected in series with switch S21.

In an embodiment of the present application, the control circuit further includes: lamp H1 and lamp H2. Lamp H1 is connected in series with switch S11; the lamp H2 is connected in series with switch S21.

The embodiments of the present application can be combined with each other, and the obtained technical solutions should also be understood to be within the scope of the present application.

The above description is not intended to limit the present application to the particular embodiments disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present application.

Claims

1. A detection switching circuit, comprising: a switch K11, a switch K21, a connection terminal, a switch K31, and a switch K41;

2. The detection switching circuit of claim 1, further comprising: a control circuit;

3. The detection switching circuit of claim 2, wherein the control circuit comprises: switch S11, coil L1, coil L2, switch S21, coil L3, and coil L4;

a first end of the switch S11 is connected with a live line L;

a first terminal of the switch S21 is connected to the live line L;

4. The detection switching circuit of claim 3, wherein the control circuit further comprises: a performance test button SB1, the performance test button SB1 including the switch S11 and a switch S12, the switch S11 being a normally open contact of the performance test button SB1, the switch S12 being a normally closed contact of the performance test button SB 1;

5. The detection switching circuit of claim 3, wherein the control circuit further comprises: an insulation resistance detection button SB2, the insulation resistance detection button SB2 including the switch S21 and a switch S22, the switch S21 being a normally open contact of the insulation resistance detection button SB2, the switch S22 being a normally closed contact of the insulation resistance detection button SB 2;

6. The detection switching circuit of claim 3, wherein the detection switching circuit comprises: a first ac contactor KM1 and a second ac contactor KM 2;

the switch K13 is connected in series with the switch S21;

7. The detection switching circuit of claim 3, wherein the detection switching circuit comprises: a third ac contactor KM3 and a fourth ac contactor KM 4;

the switch K33 is connected in series with the switch S11;

8. The detection switching circuit of claim 3, further comprising: a circuit breaker QS;

9. The detection switching circuit of claim 3, wherein the control circuit further comprises: lamp H1 and lamp H2;

the lamp H1 is connected in series with the switch S11;

the lamp H2 is connected in series with the switch S21.

10. A detection switch device comprising the detection switch circuit according to any one of claims 1 to 9.