Three-phase power indicator light device

Abstract

The invention discloses a three-phase power supply indicating lamp device, which is characterized in that a first indicating lamp can be connected between a first-phase live wire and a null line of a three-phase power supply, a second indicating lamp can be connected between a second-phase live wire and the null line of the three-phase power supply, and a third indicating lamp can be connected between a third-phase live wire and the null line of the three-phase power supply. And then the fixed support is fixed through a plurality of screw joint holes on the fixed support, so that the shell can be firmly installed at a position which can be seen obviously, when one phase of the three-phase power supply is short of power, the corresponding indicator light is turned off, and an operator on duty can find the fault in time and inform a maintainer, so that the maintainer can conveniently maintain the three-phase power supply. Therefore, the situation that the three-phase motor is started after the three-phase power supply loop has the open-phase fault can be avoided, meanwhile, a maintainer can judge which phase is lack of power according to the extinguishing conditions of the first indicator lamp, the second indicator lamp and the third indicator lamp, and the complexity and time cost of maintenance work are reduced.

Description

Technical Field

[0001] This application relates to the technical field of power equipment, and particularly to a three-phase power indicator device. Background Art

[0002] Currently, as an important production equipment in the aluminum electrolysis workshop, the multifunctional overhead crane undertakes multiple tasks such as material transportation and equipment operation. However, during the actual operation process, the multifunctional overhead crane occasionally has a fault of single-phase loss in the three-phase power supply circuit. Once this fault occurs, if the three-phase motors such as the trolley traveling motor, the crab traveling motor, the air compressor motor, and the hydraulic station motor are started continuously, it is very likely to cause the motors to burn out, and the trolley braking module may also be punctured, thus bringing huge economic losses.

[0003] In the related art, maintenance personnel usually need to check each component that may have a fault one by one, such as power lines, contactors, fuses, motors, etc. However, due to the intricate electrical system of the multifunctional overhead crane and the close interconnection between components, it is particularly difficult to locate the fault point, resulting in maintenance personnel often spending a lot of time in judging the single-phase loss fault, which undoubtedly increases the complexity and time cost of the maintenance work. Summary of the Invention

[0004] An embodiment of this application provides a three-phase power indicator device, which can solve the problem that maintenance personnel often spend a lot of time in judging the single-phase loss fault.

[0005] On the one hand, an embodiment of this application provides a three-phase power indicator device, which includes a housing, a fixing bracket, a first indicator light, a second indicator light, and a third indicator light. The housing includes an upper housing and a lower housing that are buckled with each other. The upper housing and the lower housing form a cavity structure for accommodating wires. Through holes for the wires to pass through are respectively provided at opposite ends of the lower housing. The fixing bracket is arranged on a side surface of the lower housing facing away from the upper housing. A plurality of screw holes are provided on the fixing bracket. The first indicator light, the second indicator light, and the third indicator light are arranged at intervals on the upper housing, and the first indicator light is connected between the first-phase live wire and the neutral wire of the three-phase power supply, the second indicator light is connected between the second-phase live wire and the neutral wire of the three-phase power supply, and the third indicator light is connected between the third-phase live wire and the neutral wire of the three-phase power supply.

[0006] Optionally, in some embodiments, at least three marking areas are provided on the outer surface of the upper housing, and the three marking areas respectively correspond to the first indicator light, the second indicator light, and the third indicator light.

[0007] Optionally, in some embodiments, the three-phase power indicator device further includes an emergency stop switch, which is disposed on the upper housing, and the emergency stop switch is connected in series in the power supply loop between the three-phase power supply and the electrical equipment. When at least one of the first indicator light, the second indicator light, and the third indicator light is extinguished, the emergency stop switch is pressed to disconnect the power supply loop.

[0008] Optionally, in some embodiments, the three-phase power indicator device further includes a first intermediate relay, a second intermediate relay, and a third intermediate relay. The coil of the first intermediate relay is connected between the first-phase live wire and the neutral wire. The coil of the second intermediate relay is connected between the second-phase live wire and the neutral wire. The coil of the third intermediate relay is connected between the third-phase live wire and the neutral wire. And the first normally open contact of the first intermediate relay is connected in series with the first indicator light. The first normally open contact of the second intermediate relay is connected in series with the second indicator light. The first normally open contact of the third intermediate relay is connected in series with the third indicator light.

[0009] Optionally, in some embodiments, the series circuit of the first normally open contact of the first intermediate relay and the first indicator light, the series circuit of the first normally open contact of the second intermediate relay and the second indicator light, and the series circuit of the first normally open contact of the third intermediate relay and the third indicator light are connected in parallel in sequence.

[0010] Optionally, in some embodiments, the three-phase power indicator device further includes an alarm and a switch. One end of the series connection of the alarm and the switch is connected to the neutral wire, and the other end is sequentially connected to the live wires of each phase of the three-phase power supply.

[0011] Optionally, in some embodiments, the second normally open contact of the first intermediate relay and the normally closed contact of the third intermediate relay are connected in series in the circuit between the alarm and the first-phase live wire. The second normally open contact of the second intermediate relay and the normally closed contact of the first intermediate relay are connected in series in the circuit between the alarm and the second-phase live wire. The second normally open contact of the third intermediate relay and the normally closed contact of the second intermediate relay are connected in series in the circuit between the alarm and the third-phase live wire.

[0012] Optionally, in some embodiments, the first indicator light, the second indicator light, and the third indicator light are all LED indicator lights.

[0013] Optionally, in some embodiments, the three-phase power indicator device further includes a first resistor, a second resistor, and a third resistor. The first resistor is connected in series with the first indicator light, the second resistor is connected in series with the second indicator light, and the third resistor is connected in series with the third indicator light.

[0014] Optionally, in some embodiments, the first indicator light, the second indicator light, and the third indicator light emit lights of different colors respectively.

[0015] The technical effect of a three-phase power indicator device provided by an embodiment of the present application is as follows: The first indicator light, the second indicator light, and the third indicator light are all installed on the upper shell. By buckling the upper shell and the lower shell to form a shell with a cavity structure inside, the cavity structure can accommodate the wires connected to the first indicator light, the second indicator light, and the third indicator light, and the wires can extend out from two wire passing holes on the lower shell, so that the first indicator light can be connected between the first-phase live wire and the neutral wire of the three-phase power supply, the second indicator light can be connected between the second-phase live wire and the neutral wire of the three-phase power supply, and the third indicator light can be connected between the third-phase live wire and the neutral wire of the three-phase power supply. Then, the fixing bracket is fixed through a plurality of screw holes on the fixing bracket, so that the shell can be firmly installed at a position where it can be clearly seen. When one phase of the three-phase power supply is de-energized, the corresponding indicator light will go out, and the duty personnel can timely discover this fault and notify the maintenance personnel, thereby avoiding the situation of starting a three-phase motor after a phase loss fault occurs in the three-phase power supply circuit. At the same time, the maintenance personnel can also judge which phase is de-energized according to the extinguishing conditions of the first indicator light, the second indicator light, and the third indicator light, reducing the complexity and time cost of the maintenance work. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0017] Figure 1 It is a three-dimensional structure diagram of a three-phase power indicator device in a front view angle in an embodiment of the present application;

[0018] Figure 2 It is a three-dimensional structure diagram of a three-phase power indicator device in a back view angle in an embodiment of the present application;

[0019] Figure 3 It is a circuit diagram of a three-phase power indicator device in an embodiment of the present application.

[0020] The description of the reference numerals is as follows:

[0021] 1. Housing; 11. Upper housing; 111. Marking area; 12. Lower housing; 121. Threading hole; 2. Fixed bracket; 21. Threaded hole; HL1. First indicator light; HL2. Second indicator light; HL3. Third indicator light; 3. Emergency stop switch; N. Neutral wire; L1. First-phase live wire; L2. Second-phase live wire; L3. Third-phase live wire; KA1. Coil of the first intermediate relay; KA1-1. First normally open contact of the first intermediate relay; KA1-2. Second normally open contact of the first intermediate relay; KA1-3. Normally closed contact of the first intermediate relay; KA2. Coil of the second intermediate relay; KA2-1. First normally open contact of the second intermediate relay; KA2-2. Second normally open contact of the second intermediate relay; KA2-3. Normally closed contact of the second intermediate relay; KA3. Coil of the third intermediate relay; KA3-1. First normally open contact of the third intermediate relay; KA3-2. Second normally open contact of the third intermediate relay; KA3-3. Normally closed contact of the third intermediate relay; H. Alarm; S. Switch; R1. First resistor; R2. Second resistor; R3. Third resistor. Detailed implementation

[0022] In order to make the objectives, technical solutions and advantages of this application clearer, the following further elaborates on this application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0023] It should be noted that the same or similar reference numerals in the drawings of this embodiment correspond to the same or similar components; in the description of this application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be construed as a limitation of this patent.

[0024] At the same time, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the technical features indicated. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0025] In addition, in the present invention, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Moreover, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0027] Please refer to Figure 1 and Figure 2 , which is a three-phase power indicator device provided by an embodiment of the present application. It includes a housing 1, a fixing bracket 2, a first indicator light HL1, a second indicator light HL2, and a third indicator light HL3.

[0028] It should be noted that a three-phase power supply usually includes live wires of three phases, which are respectively marked as the first phase, the second phase, and the third phase. Each live wire is responsible for providing power to the circuit. When any one of the phases has a problem, such as power loss or unstable voltage, it will affect the normal operation of the entire circuit.

[0029] Specifically, the housing 1 includes an upper housing 11 and a lower housing 12, and the upper housing 11 and the lower housing 12 can be snapped together to form a cavity structure for accommodating wires. Preferably, the upper housing 11 and the lower housing 12 are connected together by bolts. A plurality of through holes can be provided on the upper housing 11 for installing indicator lights and buttons, etc. Through holes 121 can be respectively provided at opposite ends of the lower housing 12, and the through holes 121 can allow the wires in the cavity structure to extend out.

[0030] In this embodiment, the outer contour shapes of the upper housing 11 and the lower housing 12 are both rectangular, and the formed housing 1 is a cuboid. In other embodiments, the upper housing 11 and the lower housing 12 can be of other shapes. The sizes of the upper housing 11 and the lower housing 12 can be designed according to the size of the wires and electrical equipment to be accommodated.

[0031] The fixed bracket 2 can be arranged on one side of the lower housing 12 facing away from the upper housing 11. In particular, the fixed bracket 2 is adhesively bonded to the lower housing 12. Specifically, the fixed bracket 2 can include two square plates connected at an angle to each other. In particular, the two square plates are perpendicular to each other. One of the square plates is adhesively bonded to the side surface of the lower housing 12, and the other square plate is provided with a plurality of screw holes 21 at intervals. Screws can be inserted into the screw holes 21, so that the fixed bracket 2 can be easily installed in a visible position, such as on the guardrail of the tool cart platform of a multi-functional overhead crane. Thus, the housing 1 can be easily fixed at a place visible on the ground, facilitating the duty personnel and operators to observe the three-phase power indicator device.

[0032] The first indicator light HL1, the second indicator light HL2, and the third indicator light HL3 can be arranged at intervals on the upper housing 11, and the illuminated parts of the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3 are all exposed outside the housing 1. Figure 3 , the first indicator light HL1 can be connected between the first-phase live wire L1 and the neutral wire N of the three-phase power supply, the second indicator light HL2 can be connected between the second-phase live wire L2 and the neutral wire N of the three-phase power supply, and the third indicator light HL3 can be connected between the third-phase live wire L3 and the neutral wire N of the three-phase power supply.

[0033] When a power failure occurs in one of the three phases of the three-phase power supply, the corresponding indicator light will go out. The extinguishing of the corresponding indicator light indicates that a phase loss fault has occurred in the three-phase power supply. The duty personnel or operators will promptly discover this fault and notify the maintenance personnel, thus avoiding the situation of starting a three-phase motor after a phase loss fault occurs in the three-phase power supply circuit. At the same time, the maintenance personnel can also judge which phase is lacking power through the extinguishing conditions of the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3, reducing the complexity and time cost of the maintenance work.

[0034] Please refer to Figure 1 , in some embodiments, at least three marking areas 111 can be provided on the outer surface of the upper housing 11, and the shapes of the marking areas 111 are all rectangles.

[0035] Specifically, in this embodiment, three marking areas 111 are provided on the outer surface of the upper housing 11. The three marking areas 111 respectively correspond to the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3. A label identifying the first-phase live wire L1 is provided on the marking area 111 corresponding to the first indicator light HL1, a label identifying the second-phase live wire L2 is provided on the marking area 111 corresponding to the second indicator light HL2, and a label identifying the third-phase live wire L3 is provided on the marking area 111 corresponding to the third indicator light HL3, which can facilitate the maintenance personnel to more intuitively judge which phase of the live wire is lacking phase.

[0036] Please refer to Figure 1 , in some embodiments, the three-phase power indicator device may further include an emergency stop switch 3. The emergency stop switch 3 may be disposed on the upper housing 11, and the emergency stop switch 3 can be connected in series in the power supply loop between the three-phase power supply and the electrical equipment, so that the emergency stop switch 3 can control the disconnection or closure of the power supply loop.

[0037] Specifically, when at least one of the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3 is extinguished, the emergency stop switch 3 can be pressed to disconnect the power supply loop, disconnecting the electrical equipment from the three-phase power supply with a phase loss, and avoiding damage to the electrical equipment caused by the three-phase power supply with a phase loss, thereby preventing huge economic losses.

[0038] For example, when the multi-functional overhead crane is running, if at least one of the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3 is extinguished, the emergency stop switch 3 can be pressed to shut down three-phase motors such as the trolley traveling motor, the crab traveling motor, the air compressor motor, and the hydraulic station motor, thereby avoiding the burning out of the three-phase motors.

[0039] Please refer to Figure 3 , in some embodiments, the three-phase power indicator device may further include a first intermediate relay, a second intermediate relay, and a third intermediate relay.

[0040] Specifically, the coil KA1 of the first intermediate relay can be connected between the first-phase live wire L1 and the neutral wire N, the coil KA2 of the second intermediate relay can be connected between the second-phase live wire L2 and the neutral wire N, the coil KA3 of the third intermediate relay can be connected between the third-phase live wire L3 and the neutral wire N, and the first normally open contact KA1-1 of the first intermediate relay is connected in series with the first indicator light HL1, the first normally open contact KA2-1 of the second intermediate relay is connected in series with the second indicator light HL2, and the first normally open contact KA3-1 of the third intermediate relay is connected in series with the third indicator light HL3.

[0041] Thus, when a certain phase of the live wire loses power or the voltage is unstable, the coil of the corresponding intermediate relay will lose power. At this time, the first normally open contact of this intermediate relay will change from the closed state to the open state, causing the corresponding indicator light to go out. When the staff sees the indicator light go out, they can immediately know which phase of the live wire has a phase-loss fault.

[0042] For example, if the first-phase live wire L1 loses power or has unstable voltage, the coil KA1 of the first intermediate relay loses power, the first normally open contact KA1-1 of the first intermediate relay will disconnect, and the first indicator light HL1 will go out, indicating that a single-phase loss fault has occurred in the first-phase live wire L1. Similarly, if the second-phase live wire L2 or the third-phase live wire L3 loses power, the corresponding intermediate relay coil will also lose power, its first normally open contact will disconnect, and the corresponding indicator light will also go out, respectively indicating that a single-phase loss fault has occurred in the second-phase live wire L2 or the third-phase live wire L3.

[0043] In this way, the staff can quickly and accurately identify the single-phase loss fault in the three-phase power supply, so as to take repair measures in time and avoid possible equipment damage or production interruption. Therefore, this circuit design can better display the single-phase loss fault of the three-phase power supply.

[0044] Please refer to Figure 3 , in some embodiments, the first normally open contact KA1-1 of the first intermediate relay and the first indicator light HL1 are connected in series to form a first series circuit, the first normally open contact KA2-1 of the second intermediate relay and the second indicator light HL2 are connected in series to form a second series circuit, the first normally open contact KA3-1 of the third intermediate relay and the third indicator light HL3 are connected in series to form a third series circuit, and the first series circuit, the second series circuit, and the third series circuit are connected in parallel in sequence.

[0045] Specifically, it can also be said that the left ends of the first normally open contact KA1-1 of the first intermediate relay, the first normally open contact KA2-1 of the second intermediate relay, and the first normally open contact KA3-1 of the third intermediate relay are connected in series, so that each phase live wire of the three-phase power supply is connected in parallel with the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3, which means that the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3 share the same power supply, that is, the three-phase power supply, and each phase live wire is connected in parallel with these three indicator lights. Therefore, no matter which phase live wire has a problem, it will not affect the operation of the indicator lights of other phase live wires, and it can better provide power for the three-phase power supply indicator device.

[0046] Please refer to Figure 3 , in some embodiments, the three-phase power supply indicator device may further include an alarm H and a switch S. The alarm H and the switch S can be connected in series, and one end after the alarm H and the switch S are connected in series can be connected to the neutral wire N, and the other end can be connected to each phase live wire of the three-phase power supply in sequence. This means that only when the switch S is in the closed state, the alarm H will be activated, which can avoid false alarms of the alarm H or warnings being issued without need. No matter which phase live wire has a problem, as long as the operator presses the switch S, the alarm H will issue a warning, ensuring that the response of the alarm H is comprehensive and timely.

[0047] When the operator finds that one of the three indicator lights is off, it indicates that there is a single-phase loss fault in one of the three-phase power supplies. At this time, the operator can press the switch S to make the alarm H issue a warning. This warning sound can quickly alert the personnel in the workshop and prompt them to take corresponding measures in a timely manner to handle the single-phase loss fault and prevent the fault from further expanding or causing more serious consequences.

[0048] Please refer to Figure 3 , in some embodiments, the second normally open contact KA1-2 of the first intermediate relay and the normally closed contact KA3-3 of the third intermediate relay are connected in series in the circuit between the alarm H and the first phase live wire L1. The second normally open contact KA2-2 of the second intermediate relay and the normally closed contact KA1-3 of the first intermediate relay are connected in series in the circuit between the alarm H and the second phase live wire L2. The second normally open contact KA3-2 of the third intermediate relay and the normally closed contact KA2-3 of the second intermediate relay are connected in series in the circuit between the alarm H and the third phase live wire L3.

[0049] Specifically, when the first phase live wire L1 loses power while the second phase live wire L2 is normally powered, the coil KA1 of the first intermediate relay is de-energized, the normally closed contact KA1-3 of the first intermediate relay remains closed, and the coil KA2 of the second intermediate relay is energized, and the second normally open contact KA2-2 of the second intermediate relay remains closed. At this time, the current can reach the alarm H through the normally closed contact KA1-3 of the first intermediate relay and the second normally open contact KA2-2 of the second intermediate relay, causing the alarm H to issue a warning. That is, in this case, regardless of whether the third phase live wire L3 is normally powered, the alarm H can issue a warning.

[0050] When the first phase live wire L1 and the second phase live wire L2 lose power simultaneously, the coils KA1 and KA2 of the first and second intermediate relays are both de-energized. Then, the normally closed contact KA1-3 of the first intermediate relay remains closed, and the normally closed contact KA2-3 of the second intermediate relay also remains closed. If the third phase live wire L3 is normally powered, the coil KA3 of the third intermediate relay is energized, and the second normally open contact KA3-2 of the third intermediate relay remains closed. At this time, the current can reach the alarm H through the normally closed contact KA2-3 of the second intermediate relay and the second normally open contact KA3-2 of the third intermediate relay, causing the alarm H to issue a warning.

[0051] Similarly, when the second-phase live wire L2 and the third-phase live wire L3 lose power simultaneously and the first-phase live wire L1 is normally powered, the second normally open contact KA1-2 of the first intermediate relay and the normally closed contact KA3-3 of the third intermediate relay both remain closed. At this time, current can reach the alarm H through the second normally open contact KA1-2 of the first intermediate relay and the normally closed contact KA3-3 of the third intermediate relay, causing the alarm H to issue a warning.

[0052] Therefore, it can be ensured that in the case of any two-phase live wires losing power, as long as at least one phase of the live wire is normally powered, the alarm H can be triggered, enhancing the reliability and fault detection ability of the three-phase power indicator device.

[0053] Please refer to Figure 1 , in some embodiments, the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3 are all LED indicator lights. LED indicator lights have the advantages of low power consumption, long lifespan, and fast response speed, and are very suitable for use in such alarm and indication circuits.

[0054] Please refer to Figure 3 , in some embodiments, the three-phase power indicator device may further include a first resistor R1, a second resistor R2, and a third resistor R3.

[0055] Specifically, the first resistor R1 can be connected in series with the first indicator light HL1, the second resistor R2 can be connected in series with the second indicator light HL2, and the third resistor R3 can be connected in series with the third indicator light HL3. And each resistor should be respectively connected in series between the corresponding LED indicator light and the corresponding live wire, which can limit the current passing through the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3 to ensure that the LEDs work normally and will not be damaged due to overcurrent, playing a role in protecting the circuit.

[0056] Please refer to Figure 1 , in some embodiments, the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3 emit lights of different colors respectively. The lights of different colors can help the operator quickly and accurately identify the power supply status or the working condition of the system.

[0057] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A three-phase power indicator light device, characterized in that: The invention comprises a housing (1), a fixing bracket (2), a first indicator light (HL1), a second indicator light (HL2) and a third indicator light (HL3), wherein the housing (1) comprises an upper housing (11) and a lower housing (12) which are interlocked, the upper housing (11) and the lower housing (12) forming a cavity structure for accommodating electric wires, the opposite ends of the lower housing (12) are respectively provided with threading holes (121) for the electric wires to pass through, the fixing bracket (2) is arranged on a side surface of the lower housing (12) which is away from the upper housing (11), and the fixing bracket (2) is arranged on a side surface of the lower housing (12) which is away from the upper housing (11). The bracket (2) is provided with a plurality of screw holes (21); the first indicator light (HL1), the second indicator light (HL2) and the third indicator light (HL3) are arranged at intervals on the upper housing (11); the first indicator light (HL1) is connected between a first-phase live wire (L1) and a neutral wire (N) of a three-phase power supply; the second indicator light (HL2) is connected between a second-phase live wire (L2) and a neutral wire (N) of the three-phase power supply; and the third indicator light (HL3) is connected between a third-phase live wire (L3) and a neutral wire (N) of the three-phase power supply.

2. The three-phase power indicator light device according to claim 1, characterized in that: The outer surface of the upper shell (11) is provided with at least three marking areas (111), and the three marking areas (111) respectively correspond to the first indicator light (HL1), the second indicator light (HL2) and the third indicator light (HL3).

3. The three-phase power indicator light device according to claim 1, characterized in that: The device also comprises an emergency stop switch (3), the emergency stop switch (3) being arranged on the upper housing (11), and the emergency stop switch (3) being connected in series to the power supply circuit of the three-phase power supply and the electrical equipment, and when at least one of the first indicator light (HL1), the second indicator light (HL2) and the third indicator light (HL3) is off, pressing the emergency stop switch (3) disconnects the power supply circuit.

4. The three-phase power indicator light device according to claim 1, characterized in that: It also includes a first intermediate relay, a second intermediate relay and a third intermediate relay, wherein the coil (KA1) of the first intermediate relay is connected between the first phase live wire (L1) and the neutral wire (N), the coil (KA2) of the second intermediate relay is connected between the second phase live wire (L2) and the neutral wire (N), the coil (KA3) of the third intermediate relay is connected between the third phase live wire (L3) and the neutral wire (N), and the first normally open contact (KA1-1) of the first intermediate relay is connected in series with the first indicator light (HL1), the first normally open contact (KA2-1) of the second intermediate relay is connected in series with the second indicator light (HL2), and the first normally open contact (KA3-1) of the third intermediate relay is connected in series with the third indicator light (HL3).

5. The three-phase power indicator light device according to claim 4, characterized in that: A series circuit of a first normally open contact (KA1-1) of the first intermediate relay and the first indicator light (HL1), a series circuit of a first normally open contact (KA2-1) of the second intermediate relay and the second indicator light (HL2), and a series circuit of a first normally open contact (KA3-1) of the third intermediate relay and the third indicator light (HL3) are sequentially connected in parallel.

6. The three-phase power indicator light device according to claim 4, characterized in that: It also includes an alarm (H) and a switch (S), wherein one end of the alarm (H) and the switch (S) connected in series is connected to the neutral line (N), and the other end is connected to the live wires of each phase of the three-phase power supply in sequence.

7. The three-phase power indicator light device according to claim 6, characterized in that: The second normally open contact (KA1-2) of the first intermediate relay and the normally closed contact (KA3-3) of the third intermediate relay are connected in series in the circuit between the alarm (H) and the first phase live wire (L1), the second normally open contact (KA2-2) of the second intermediate relay and the normally closed contact (KA1-3) of the first intermediate relay are connected in series in the circuit between the alarm (H) and the second phase live wire (L2), and the second normally open contact (KA3-2) of the third intermediate relay and the normally closed contact (KA2-3) of the second intermediate relay are connected in series in the circuit between the alarm (H) and the third phase live wire (L3).

8. The three-phase power indicator light device according to claim 1, characterized in that: The first indicator light (HL1), the second indicator light (HL2) and the third indicator light (HL3) are all LED indicator lights.

9. The three-phase power indicator light device according to claim 8, characterized in that: It also includes a first resistor (R1), a second resistor (R2) and a third resistor (R3), wherein the first resistor (R1) is connected in series with the first indicator light (HL1), the second resistor (R2) is connected in series with the second indicator light (HL2), and the third resistor (R3) is connected in series with the third indicator light (HL3).

10. The three-phase power indicator light device according to claim 1, characterized in that: The first indicator light (HL1), the second indicator light (HL2) and the third indicator light (HL3) respectively emit lights of different colors.

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