Shandong Three phase Asynchronous Motor Factory teaches you how to quickly solve motor failure problems
1、 Three phase AC asynchronous motor cannot start normally
1. The manifestation of the fault of three-phase AC asynchronous motor unable to start normally
For the operation of three-phase asynchronous motors, their faults are mainly mechanical and electrical. The main cause of electrical faults is the fault between the electronic winding and the stator. Mechanical failures include the occurrence of various mechanical component failures.
The specific fault phenomena that prevent three-phase AC motors from starting normally include the following aspects:
(1) At the beginning of startup, the power cord was not connected and the motor was in a dead state;
(2) The power cord breaks or the fuse burns out;
(3) The equipment is in an overloaded state;
(4) Due to startup errors or improper operation, electric motors with coil rotors may experience issues with power supply current regulation, resulting in power supply current and voltage values that do not meet the requirements for normal motor operation.
2. Fault repair methods
(1) In the maintenance work, check in advance whether the hardware facilities such as power switches, power lines, power voltage and current, fuses, etc. are normal, and promptly deal with and repair the problems that exist in these aspects.
(2) Check whether the fuse and voltage are suitable for the operation requirements of the motor. If it cannot be guaranteed, the method of replacing the fuse can be directly used for inspection. For voltage and current, a multimeter, voltmeter, and ammeter can be used for inspection. Conduct detailed and in-depth calculations of the operating load of the equipment where the motor is located, and make reasonable choices based on the operating efficiency of the motor and equipment.
(3) Check whether there is a mechanical transmission failure inside the motor, mainly analyzing equipment such as fans, stator coils, and rotor coils.
2、 Abnormal noise after starting asynchronous motor
1. Fault inspection
If the electric motor makes a buzzing sound after being powered on normally
(1) The link that needs to be checked is the power supply voltage and current value of the motor. Due to the low voltage and current of the motor power supply, some internal components of the motor cannot operate effectively, resulting in buzzing sounds.
(2) Check if the coil connections inside the motor are reasonable and if the winding connections are connected to the correct direction.
(3) Check if the operation between the stator, rotor, and winding is normal.
2. Exclusion method
(1) To check the current status of the power supply voltage and current, identify the short circuit situation of the power supply current and voltage, and scientifically handle related issues.
(2) Using other means to reduce the specific operating load of mechanical equipment, and even in special circumstances, replacing the electric motor can be used for maintenance.
(3) Reassemble the equipment to promptly solve various internal faults, adjust the distance between the winding, stator, and rotor reasonably, and recalculate and allocate the parameters of the winding to ensure the stability of the system operation.
3、 The temperature rises sharply during the operation of the electric motor
1. Cause of malfunction
During the operation of a three-phase asynchronous motor, if there are phenomena such as high power supply voltage and current, it will inevitably cause the temperature of the internal chip to rise, leading to certain faults.
At the same time, if the motor starts and stops too frequently during operation, the rapid increase in current during the starting process can also cause motor operation faults.
In the normal operation of an electric motor, faults such as short circuits and grounding between the winding and stator will inevitably cause the current to quickly pass through the copper coil during operation. At this time, on the one hand, it will increase the current loss in the copper coil during operation, and on the other hand, it will also cause faults in the motor fan, ultimately leading to the inability of the motor's heat dissipation function and causing mechanical burnout and other faults.
2. Fault handling methods
(1) Check in advance whether the equipment is in an overloaded operating state, control the power supply current and voltage reasonably, and choose as many thick power supply wires as possible to increase the power supply current and voltage.
(2) During the inspection, it is necessary to promptly check the assembly of the stator, rotor, and winding coils, clean the dust and debris inside the motor in a timely manner, and ensure the normal operation of the air supply system and cooling system.
4、 Severe vibration during the operation of the electric motor
During normal operation, electric motors are inevitably affected by various external factors, including insulation damage, changes in power supply voltage and current, and grounding issues. Once these problems occur, they will inevitably have an impact on the operation of the motor, ultimately leading to vibration and other phenomena.
1. Cause of malfunction
If the bearings of the equipment are damaged, it will cause vibration exceeding the standard;
Defects in various components and dimensions of the electric motor itself are the main causes of vibration problems;
Uneven air gap of stator or rotor, rotor imbalance, etc; Unbalanced installation of end caps or fans; The coupling assembly is incorrect, resulting in looseness issues; Insufficient strength of the casing or its foundation; The screws of the motor foundation are loose, and instability occurs during operation.
2. Solution measures
To address this issue, it is necessary to check whether the bearing balls are damaged and replace the faulty bearings in a timely manner; Disassemble and inspect the electric motor, and take timely measures to deal with it; Check the air gap condition and maintain uniformity; Adjust the balance of the rotor; Strengthen or remake the foundation to ensure consistency with the specified values for motor operation; Strengthen the foundation screws; Reinstall the motor and repair the rotor winding.
In short, in order to better ensure the normal operation of the motor, correct, scientific, and reasonable maintenance methods should be adopted to promptly deal with various faults that occur during the operation of the motor. But in order to do these aspects of work well, it is necessary to have a deep understanding of the causes and characteristics of various common faults in electric motors. Only in this way can the causes and locations of motor faults be determined in a timely and accurate manner, and maintenance measures can be taken quickly to restore the motor to normal state.
