CN-116155048-B - Automatic control method for motor space heater

CN116155048BCN 116155048 BCN116155048 BCN 116155048BCN-116155048-B

Abstract

The invention relates to an automatic control method for a motor space heater, and belongs to the technical field of motor power distribution. The method comprises the following steps of S1, connecting a motor switching-off loop on a main power supply loop, S2, connecting the main power supply loop from a power supply to a motor space heater through a circuit breaker and a contactor and a cable, S3, disconnecting an auxiliary motor switching-off contact, releasing the intermediate relay after losing power, closing the contact of the intermediate relay, enabling a normally open contact of the contactor to be attracted, and enabling the motor space heater to be in a normal heating state. The invention has simple principle, can be realized by utilizing the most commonly used control loop for transformation, has low cost, low energy consumption and convenient operation, and can greatly avoid the potential safety hazard that the insulation of the motor is lower than the standard value, and the motor is extremely easy to generate malignant electrical accidents and cause serious damage to the motor when the starter is restarted.

Inventors

CHEN XIAOCHUN
Sui Peiyong
BI ZUOBIN

Assignees

青岛思远化工有限公司

Dates

Publication Date: 20260508
Application Date: 20211119

Claims (3)

1. An automatic control method for a space heater of an electric motor is characterized by comprising the following steps: S1, connecting a motor brake-separating loop on a main power supply loop, wherein: the main power supply loop comprises a circuit breaker (1), a contactor (2) and a motor space heater (3) which are connected in sequence; The motor brake-separating loop comprises a test total insurance (4), a test node (5), a brake-separating auxiliary contact (7) and an intermediate relay (8); S2, connecting a main power supply loop from a power supply to a motor space heater (3) through a breaker (1) and a contactor (2) by a cable, wherein: S21, connecting the lower side of the live wire insurance (6) to an opening and closing auxiliary contact (7) of the high-voltage motor control circuit breaker (1) through a cable, then connecting to a coil of the intermediate relay (8), and returning to zero at the other side of the coil; s22, a live wire safety (6) is connected to a coil of the contactor (2) through a normally closed contact of the intermediate relay (8), and the other side of the coil returns to zero; S23, a normally closed contact of a contact device (2) at the lower side of the live wire safety device (6) is connected to an indicator light HG1, and the other side of the indicator light HG1 returns to zero; S24, connecting a normally open contact of a contact device (2) at the lower side of the live wire safety device (6) to an HR1 switching-off indicator lamp, and returning to zero at the other side of the HR1 switching-off indicator lamp, wherein the loop is used as a loop switching-on indication of a motor space heater (3); S3, the motor opening and closing auxiliary contact (7) is opened, the intermediate relay (8) is released after power failure, and 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 powered on in a normal heating state; The motor brake-separating loop is arranged on an independent power supply, the independent power supply is connected into a main power supply loop, and the motor brake-separating loop is connected with the HG1 brake-closing indicator lamp and the HR1 brake-separating indicator lamp in parallel; In the step S1, a test node (5) of the motor brake-separating loop can turn a circuit to a main power supply loop or the motor brake-separating loop so as to form a closed loop; in the step S1, a current transformer is connected in series between the input end of the motor space heater (3) and the main contact of the contactor (2).
2. The automatic motor space heater control method according to claim 1, wherein in the step S1, the circuit breaker (1) is a miniature circuit breaker.
3. The automatic motor space heater control method according to claim 1, wherein in the step S1, a fuse is mounted at a main contact end of the contactor (2).

Description

Automatic control method for motor space heater Technical Field The invention relates to an automatic control method for a motor space heater, and belongs to the technical field of motor power distribution. Background The motor space heater heats the inner space of the case when the motor is in a standby state, and prevents the stator winding from being wet and insulating to be reduced, thereby generating malignant electrical accidents and causing serious damage to the motor. In cold areas with high air humidity, coastal areas, corrosion of the motor can also be prevented. And heating can keep the internal micro-positive pressure of the motor, so as to prevent external salt gas from entering the motor. Therefore, when the motor is in a standby state, the normal operation of the motor space heater plays a vital role, and in normal control, the motor space heater is put into operation by manual operation, for example, a person forgets to put the motor space heater into operation, the moisture insulation of a motor stator winding is reduced, and malignant electrical accidents are easy to occur and the motor is seriously damaged. Disclosure of Invention Aiming at the defects in the prior art, the invention provides an automatic control method of a motor space heater, namely an automatic control method for putting into operation, and a method for stopping the motor space heater from being put into operation in a state that a high-voltage motor is stopped and a circuit breaker is controlled to rotate for maintenance by the high-voltage motor can be avoided. The motor space heater is in a normal heating state whenever the motor is stopped, providing a powerful support for good motor standby. The automatic control method of the motor space heater comprises the following steps: S1, connecting a motor brake-separating loop on a main power supply loop, wherein: The main power supply loop comprises a circuit breaker, a contactor and a motor space heater which are connected in sequence; the motor brake-separating loop comprises a test total insurance, a test node, a brake-separating auxiliary contact and an intermediate relay; s2, connecting a main power supply loop from a power supply to a motor space heater through a breaker and a contactor and a cable, wherein: S21, connecting the lower side of the live wire insurance to an opening and closing auxiliary contact of a high-voltage motor control circuit breaker through a cable, and then connecting to an intermediate relay coil, and returning to zero at the other side of the coil; S22, a fire wire insurance is connected to a contactor coil after passing through a normally closed contact of the intermediate relay, and the other side of the coil returns to zero; S23, a normally closed contact of a fire wire safety lower side contact connector is connected to an indicator light HG1, and the other side of the indicator light HG1 returns to zero; S24, connecting a normally open contact of a contact breaker of the lower side of the live wire safety with an HR1 switching-off indicator lamp, and returning the other side of the HR1 switching-off indicator lamp to zero, wherein the loop is used as a switching-on indication of a motor space heater loop; and S3, the motor opening and closing auxiliary contact is opened, the intermediate relay is released after power failure, and the contact of the intermediate relay is closed, so that the normally open contact of the contactor is attracted, and the motor space heater is electrified and is in a normal heating state. Preferably, in the step S1, the motor brake-off loop is arranged on an independent power supply, the independent power supply is connected to the main power supply loop, and the motor brake-off loop is connected in parallel with the HG1 brake-on indicator lamp and the HR1 brake-off indicator lamp loop. Preferably, in the step S1, the circuit breaker is a miniature circuit breaker. Preferably, in the step S1, the test node of the motor brake-off loop is capable of turning the line to the main power supply loop or the motor brake-off loop to form a closed loop. The principle of the invention is as follows: When the motor brake separating button is pressed down during operation, the motor brake separating auxiliary contact QF is opened, the intermediate relay KA is released after power failure, the KA auxiliary contacts KA 13-KA 14 are closed, the contactor KM is attracted, the coil of the contactor 1 is electrified, the motor space heater is electrified to be in a normal heating state, meanwhile, the normally open contact opening point of the contactor is closed, and the HG1 brake indicating lamp is lighted. When the motor is stopped, a motor closing button is pressed, a motor opening and closing auxiliary contact is closed, the intermediate relay 8 is electrified and closed, the KA auxiliary contacts KA 13-KA 14 are opened, so that the contactor 2 is released when power is lost, the motor space heater 3 is in a heating sto