Automatic control method for motor space heater

Abstract

The application relates to an automatic control method of a motor space heater, and belongs to the technical field of motor power distribution. The application comprises the following steps: S1, connecting a motor switching-off circuit on a main power supply circuit; S2, connecting the main power supply circuit from a power source to the motor space heater through a circuit breaker, a contactor and a cable; S3, disconnecting a motor switching-on and switching-off auxiliary contact, releasing an intermediate relay by losing power, closing the contact of the intermediate relay, absorbing the normally open contact of the contactor, and electrifying the motor space heater to be in a normal heating state. The application has the advantages of simple principle, low cost, low energy consumption, convenient operation, and great safety hidden danger of avoiding the motor insulation being lower than the standard value, and the motor being easily damaged by a serious electrical accident when being started again.

Description

Technical Field

[0001] This invention relates to an automatic control method for a space heater powered by an electric motor, belonging to the field of electric motor power distribution technology. Background Technology

[0002] The motor space heater heats the internal space of the motor chassis when the motor is in standby mode to prevent moisture from reducing the insulation of the stator windings, which could lead to serious electrical accidents and severe damage to the motor. In areas with high humidity, cold temperatures, and coastal regions, it also helps prevent motor corrosion. Furthermore, heating maintains a slight positive pressure inside the motor, preventing external salt gases from entering. Therefore, the normal operation of the motor space heater is crucial when the motor is in standby mode. Normally, the motor space heater is manually activated. If personnel forget to activate it, the stator windings can become damp, reducing insulation and easily leading to serious electrical accidents and severe damage to the motor. Summary of the Invention

[0003] To address the aforementioned shortcomings of existing technologies, this invention proposes an automatic control method for a motor-driven space heater, specifically an automatic control method for operation. This method avoids the issue of the space heater being deactivated when the high-voltage motor control circuit breaker is switched to maintenance mode even when the high-voltage motor is stopped. The space heater remains in normal heating mode as long as the motor is stopped, providing strong support for reliable motor standby.

[0004] The automatic control method for a space heater powered by an electric motor according to the present invention includes the following steps:

[0005] S1: Connect the motor tripping circuit to the main power supply circuit, where:

[0006] The main power supply circuit includes a circuit breaker, a contactor, and a motor space heater connected in sequence;

[0007] The motor tripping circuit includes a test main fuse, a test node, auxiliary contacts for tripping and closing, and an intermediate relay;

[0008] S2: The main power supply circuit connects from the power source through a circuit breaker, a contactor, and then a cable to the motor space heater, where:

[0009] S21: The lower side of the live wire fuse is connected to the opening and closing auxiliary contacts of the high-voltage motor control circuit breaker via a cable, and then connected to the intermediate relay coil. The other side of the coil returns to zero.

[0010] S22: The live wire fuse is connected to the contactor coil via the normally closed contact of the intermediate relay, and the other side of the coil returns to zero;

[0011] S23: The normally closed contact of the contactor on the lower side of the live wire fuse is connected to indicator light HG1, and the other side of indicator light HG1 returns to zero; this circuit serves as the tripping indicator for the motor space heater circuit.

[0012] S24: Connect a wire from the normally open contact of the contactor on the lower side of the live wire fuse to the HR1 trip indicator light. The other side of the HR1 trip indicator light returns to zero. This circuit serves as the closing indicator for the motor space heater circuit.

[0013] S3: The motor's opening and closing auxiliary contacts open, the intermediate relay is de-energized and released, the intermediate relay contacts close, causing the normally open contacts of the contactor to be energized, and the motor's space heater is energized and put into normal heating state.

[0014] Preferably, in step S1, the motor tripping circuit is set on an independent power supply, which is connected to the main power supply circuit. The motor tripping circuit is connected in parallel with the HG1 closing indicator and HR1 tripping indicator circuits.

[0015] Preferably, in step S1, the circuit breaker is a miniature circuit breaker.

[0016] Preferably, in step S1, the test node of the motor tripping circuit can switch the line to the main power supply circuit or the motor tripping circuit to form a closed circuit.

[0017] The principle of this invention is as follows:

[0018] When running, pressing the motor trip button will disconnect the motor trip and closing auxiliary contact QF, de-energize the intermediate relay KA, and close the KA auxiliary contacts KA:13-KA:14, causing the contactor KM to be energized. The contactor 1 coil will be energized, and the motor space heater will be energized and put into normal heating mode. At the same time, the normally open contact of the contactor will close, and the HG1 closing indicator light will illuminate.

[0019] When stopping: Press the motor closing button, the motor opening and closing auxiliary contacts close, the intermediate relay 8 is energized and energized, the KA auxiliary contacts KA:13-KA:14 open, causing the contactor 2 to de-energize and release, the motor space heater 3 de-energizes and enters the stopped heating state, at the same time, the normally open contact 9 of the contactor closes, and the HR1 opening indicator light illuminates.

[0020] It should be noted that:

[0021] When the motor trips, even if the motor control circuit breaker is switched to maintenance (requiring the removal of the secondary plug-in of the circuit breaker), the motor tripping auxiliary contact QF remains open. The intermediate relay KA is de-energized and released, and the KA auxiliary contacts KA:13-KA:14 close, causing the contactor KM to engage. The motor space heater is then energized and enters normal heating mode.

[0022] The beneficial effects of the present invention are as follows: The automatic control method for the electric motor space heater described in this invention is simple in principle and can be achieved by modifying the most commonly used control circuit. It is low in cost, low in energy consumption, and easy to operate. It can greatly avoid the safety hazard that the insulation of the electric motor may drop below the standard value, which could easily lead to a serious electrical accident and cause serious damage to the electric motor when it is restarted. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention.

[0024] Figure 2 This is a flowchart illustrating the principle of the present invention.

[0025] In the diagram: 1. Circuit breaker; 2. Contactor; 3. Motor space heater; 4. Test main fuse; 5. Test node; 6. Live wire fuse; 7. Auxiliary contact for opening and closing; 8. Intermediate relay; 9. Normally open contact of contactor; 10. Normally closed contact of contactor. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1:

[0028] like Figure 1 and Figure 2 As shown, the automatic control method for the electric motor space heater described in this invention is an automatic control method for putting the motor into operation. This method avoids the situation where the electric motor space heater 3 is deactivated even when the high-voltage motor is stopped, but the high-voltage motor control circuit breaker 1 is under maintenance. As long as the motor is stopped, the electric motor space heater 3 is in normal heating mode, providing strong support for the motor's reliable standby.

[0029] Specifically, the present invention includes the following steps:

[0030] S1: Connect the motor tripping circuit to the main power supply circuit, such as... Figure 1 As shown, where:

[0031] The main power supply circuit includes a circuit breaker 1, a contactor 2, and a motor space heater 3 connected in sequence;

[0032] The motor tripping circuit includes a test fuse 4, a test node 5, a tripping and closing auxiliary contact 7, and an intermediate relay 8;

[0033] S2: The main power supply circuit connects from the power source through circuit breaker 1, contactor 2, and then through a cable to the motor space heater 3. Figure 2 As shown, where:

[0034] S21: The lower side of the live wire fuse 6 is connected to the opening and closing auxiliary contact 7 of the high-voltage motor control circuit breaker 1 via a cable, and then connected to the coil of the intermediate relay 8. The other side of the coil returns to zero.

[0035] S22: The live wire fuse 6 is connected to the coil of contactor 2 via the normally closed contact of intermediate relay 8, and the other side of the coil returns to zero;

[0036] S23: The normally closed contact of the contactor 2 on the lower side of the live wire fuse 6 is connected to the indicator light HG1, and the other side of the indicator light HG1 returns to zero; this circuit serves as the trip indication for the motor space heater 3 circuit.

[0037] S24: Connect a wire to the normally open contact of the contactor 2 below the live wire fuse 6 to the HR1 trip indicator light. The other side of the HR1 trip indicator light returns to zero. This circuit serves as the closing indicator for the motor space heater 3 circuit.

[0038] S3: The motor opening and closing auxiliary contact 7 is opened, the intermediate relay 8 is de-energized and released, the contacts of the intermediate relay 8 are closed, so that the normally open contact 9 of the contactor is attracted, and the motor space heater 3 is energized and put into normal heating state.

[0039] Preferably, in step S1, the motor tripping circuit is set on an independent power supply, which is connected to the main power supply circuit. The motor tripping circuit is connected in parallel with the HG1 closing indicator and HR1 tripping indicator circuits.

[0040] Preferably, in step S1, the circuit breaker 1 is a miniature circuit breaker.

[0041] Preferably, in step S1, the test node 5 of the motor tripping circuit can switch the line to the main power supply circuit or the motor tripping circuit to form a closed circuit.

[0042] The principle of this invention is as follows:

[0043] During operation, pressing the motor trip button opens the motor trip and closing auxiliary contacts, de-energizes the intermediate relay 8, and closes the KA auxiliary contacts KA:13-KA:14, energizing the contactor 2 and putting the motor space heater 3 into normal heating mode. At the same time, the normally closed contact 10 of the contactor closes, and the HG1 closing indicator light illuminates.

[0044] When stopping: Press the motor closing button, the motor opening and closing auxiliary contacts close, the intermediate relay 8 is energized and energized, the KA auxiliary contacts KA:13-KA:14 open, causing the contactor 2 to de-energize and release, the motor space heater 3 de-energizes and enters the stopped heating state, at the same time, the normally open contact 9 of the contactor closes, and the HR1 opening indicator light illuminates.

[0045] It should be noted that:

[0046] When the motor trips, even if the motor control circuit breaker 1 is switched to maintenance (requiring the removal of the secondary plug of circuit breaker 1), the motor tripping auxiliary contacts remain open. The intermediate relay 8 is de-energized and released, and the KA auxiliary contacts KA:13-KA:14 close, causing the contactor 2 to engage. The motor space heater 3 is then energized and enters normal heating mode.

[0047] The beneficial effects of the present invention are as follows: The automatic control method for the electric motor space heater described in this invention is simple in principle and can be achieved by modifying the most commonly used control circuit. It is low in cost, low in energy consumption, and easy to operate. It can greatly avoid the safety hazard that the insulation of the electric motor may drop below the standard value, which could easily lead to a serious electrical accident and cause serious damage to the electric motor when it is restarted.

[0048] This invention can be widely used in electric motor power distribution applications.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automatic control method for an electric motor space heater, characterized in that, Includes the following steps: S1: Connect the motor tripping circuit to the main power supply circuit, where: The main power supply circuit includes a circuit breaker (1), a contactor (2), and a motor space heater (3) connected in sequence; The motor tripping circuit includes a test fuse (4), a test node (5), tripping and closing auxiliary contacts (7), and an intermediate relay (8); S2: The main power supply circuit is connected from the power source through the circuit breaker (1), contactor (2), and then through the cable to the motor space heater (3), wherein: S21: The lower side of the live wire fuse (6) is connected to the opening and closing auxiliary contact (7) of the high-voltage motor control circuit breaker (1) via a cable, and then connected to the coil of the intermediate relay (8). The other side of the coil returns to zero. S22: The live wire fuse (6) is connected to the coil of the contactor (2) via the normally closed contact of the intermediate relay (8), and the other side of the coil returns to zero; S23: The normally closed contact of the contactor (2) below the live wire fuse (6) is connected to the indicator light HG1, and the other side of the indicator light HG1 returns to zero; this circuit serves as the circuit trip indication for the space heater (3) of the motor. S24: The normally open contact of the contactor (2) below the live wire fuse (6) is connected to the HR1 trip indicator light, and the other side of the HR1 trip indicator light returns to zero; this circuit serves as the closing indicator for the motor space heater (3) circuit; S3: The motor opening and closing auxiliary contact (7) is opened, the intermediate relay (8) is de-energized and released, the contact of the intermediate relay (8) is closed, so that the normally open contact (9) of the contactor is attracted, and the motor space heater (3) is energized and in normal heating state. The motor tripping circuit is set on an independent power supply, which is connected to the main power supply circuit. The motor tripping circuit is connected in parallel with the HG1 closing indicator and HR1 tripping indicator circuits. In step S1, the test node (5) of the motor tripping circuit can switch the line to the main power supply circuit or the motor tripping circuit to form a closed circuit. In step S1, a current transformer is connected in series between the input terminal of the motor space heater (3) and the main contact of the contactor (2).

2. The automatic control method for a space heater powered by an electric motor according to claim 1, characterized in that, In step S1, the circuit breaker (1) is a miniature circuit breaker.

3. The automatic control method for a space heater powered by an electric motor according to claim 1, characterized in that, In step S1, a fuse is installed at the main contact end of the contactor (2).

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