As a widely used equipment in modern industry and daily life, the normal operation of motors is crucial for the smooth progress of production and life. However, various faults may occur during the operation of the motor, and timely and accurate troubleshooting is the key to ensuring the normal operation of the motor. So, how to troubleshoot is the focus of this article. The article may be cumbersome and requires careful repetition of reading. If there is anything you don't understand, please click on the link to contact us, and Fuxing Motor will answer your questions.
A.What should we do when a malfunction occurs?
a.Observation and inquiry:Firstly, observe the appearance of the electric motor to see if there is any smoke, odor, abnormal noise, etc. Inquire with the operator about the operation status of the motor before and after the fault, including load changes, operation steps, etc.
b.Measurement and testing:Use tools for measurement and inspection. For example, using a multimeter to measure power supply voltage and winding resistance; Measure the insulation resistance of the winding with a megohmmeter; Check the wear of the bearings (please refer to section B, section c for details); Check if the fan is running properly, etc.
c.Analysis and judgment:Based on the results of observation, measurement, and inspection, comprehensively analyze and determine the cause of the malfunction. For complex faults, a step-by-step troubleshooting method can be used to narrow down the scope of the fault.
d.Fault handling:Take corresponding measures to address the identified cause of the malfunction.
B.What are the common motor faults?
a.Motor cannot start: One of the common faults is that the motor cannot start. The possible reasons and elimination methods are as follows:
Power supply issue: Check if the power supply is properly connected, including whether the power cord is damaged, whether the plug is loose, etc. Measure whether the power supply voltage meets the rated voltage of the motor. Low or high voltage may cause the motor to fail to start.
Motor winding fault: Measure the resistance of the motor winding with a multimeter to determine if there is an open circuit or short circuit. If the winding is open or short circuited, it needs to be rewound or replaced.
Mechanical malfunction: Check if the motor shaft is stuck and if it rotates smoothly. Check whether the transmission device is normal, such as whether the belt is too tight, whether the coupling is loose, etc.
Startup circuit fault: Check if the startup capacitor is damaged. If it is damaged, replace it with a new capacitor. Check if the starting relay is working properly, and repair or replace it if there is a malfunction.
b.Motor overheating: Motor overheating may affect the performance and lifespan of the motor, and even lead to motor burnout. Here are some possible reasons and solutions (to learn more about motor overheating, please click here):
Overload operation: Check if the load carried by the motor exceeds its rated load, and if overloaded, reduce the load.
Abnormal power supply voltage: High or low power supply voltage can cause the motor to heat up, and the power supply voltage should be adjusted to the normal range.
Local short circuit of motor winding: Determine the existence of a short circuit point by measuring the winding resistance or conducting insulation testing, and repair it.
Poor ventilation: Clean the motor ventilation duct to ensure good heat dissipation of the motor. Check if the fan is running properly and replace it promptly if it is damaged.
c.Abnormal noise during motor operation: Abnormal noise during motor operation may be caused by the following reasons
Bearing malfunction: Listen to the sound to determine if the bearing is worn or damaged, and replace it with a new one if necessary. When the motor bearing fails, the following typical sounds may be emitted:
Sharp whistling sound: This usually indicates poor lubrication of the bearing or wear on the surface of the bearing ball or raceway.
Low rumbling sound: It may be due to significant wear or peeling of the bearing ball or raceway, or excessive load on the bearing.
Uneven impact sound: often caused by reasons such as bearing ball breakage or damage to the cage.
Continuous friction sound: It means that there is severe friction inside the bearing, which may be due to improper installation, tight fit between the shaft and the bearing, and other issues.
Friction between motor stator and rotor: Check whether the gap between the stator and rotor is uniform, and adjust it if there is any unevenness.When there is a friction fault between the motor rotor and stator, the following sounds may be produced:
Sharp scraping sound: Similar to metal objects scraping against each other, the sound is quite harsh, which usually indicates mild friction between the rotor and stator.
Dull collision sound: It seems like heavy objects are colliding with each other, with a low and powerful sound, which may indicate severe friction.
Continuous "rustling" sound: a sound similar to the friction of sand, indicating the existence of continuous slight contact and friction between the rotor and stator.
The motor installation is not secure: Tighten the installation bolts of the motor to ensure a stable installation. When the motor is not securely installed, the following sounds may be emitted:
Intermittent "clanging" sound: This sound is relatively crisp, as if a component is loosening and colliding. It is usually caused by intermittent shaking and collision of the motor body due to unstable installation during operation.
Low pitched "buzzing" resonance sound: The sound is relatively dull, which is due to the motor not being installed firmly, and the vibration frequency generated during operation is close to the natural frequency of the motor itself, causing resonance.
Disorderly "creaking" sound: similar to the sound of old wooden boards under pressure, indicating that the unstable installation position of the motor during operation causes uneven stress on various components, resulting in irregular compression and friction.
d.Abnormal motor speed: Abnormal motor speed may affect the working efficiency of the equipment. The reasons and solutions are as follows
Unstable power frequency: Use a stable frequency power supply or check if the grid frequency is normal.
Winding fault: Short circuit or open circuit of the winding can cause abnormal motor speed. Repair or replace the winding.
Speed control device malfunction: For speed control motors, check if the speed control device is working properly and perform corresponding repairs or replacements.
C.Measures to prevent motor failures
a.Regular maintenance: including cleaning the motor, checking the wiring terminals, adding lubricating oil, measuring insulation resistance, etc.
b.Reasonable use: Avoid motor overload, frequent starting, and forward/reverse switching, and operate according to the rated parameters of the motor.
c.Improving the operating environment: Ensure that the motor operates in a well ventilated environment with appropriate temperature and humidity, and avoid the influence of dust, water vapor, etc. on the motor.
In short, troubleshooting electric motors requires a certain level of professional knowledge and skills, while following scientific methods and steps. By promptly and accurately troubleshooting and taking effective preventive measures, the service life of the motor can be extended, and the reliability and stability of the equipment can be improved.