As the core power equipment in industrial production and civil electrical systems, the stable operation of motors directly determines production efficiency and equipment reliability. Scientific operation and maintenance practices are key to extending motor life and reducing failure rates. According to statistics, over 90% of motor damage stems from insufficiently detailed routine inspections and inadequate maintenance. Most failures can be prevented and avoided through standardized operations. This article combines front-line operation and maintenance practical cases with standardized processes, summarizing five key practices that can be directly implemented to help you effectively safeguard the health of motors and effectively extend their service life.
Key operation 1: Precise control of load to prevent overload operation.
Overload is the primary cause of motor burnout. Long-term high-load operation can lead to overheating of the windings, accelerated insulation aging, as well as bearing wear, abnormal current increase, and other cascading failures. In severe cases, it can directly burn out the motor windings, causing economic losses. Many operation and maintenance personnel tend to overlook the impact of load fluctuations and only focus on the operating status of the motor itself, resulting in the motor being in a "overload operation" state for a long time, which shortens its service life.
The key points of practical operation require consideration of both "monitoring" and "control": First, monitor the operating current in real time, using a clamp ammeter to regularly detect the three-phase current, ensuring that the current is within the rated range and that the error between each phase current and the average value does not exceed 10%. If one or more phase currents are found to be abnormally high, the machine should be stopped immediately to investigate the cause. Second, optimize load control to avoid long-term full-load or overload operation of the motor. For motors driving equipment such as conveyor belts and water pumps, it is necessary to install material detection and blockage detection devices to prevent sudden surges in load. At the same time, reasonably match the motor power parameters according to the load demand to avoid situations where "a big horse pulls a small cart" or "a small horse pulls a big cart". Third, standardize the setting of protective devices, install overload protection equipment such as thermal relays and electronic protectors, and set reasonable warning thresholds based on the rated current of the motor. When the current exceeds the set value, the protective device can automatically cut off the power supply to avoid long-term overload operation of the motor.
Practical reminder: Due to long-term high-load operation, the Siemens 1LE0001 water pump motor in a certain factory suddenly triggered an overload alarm, with the motor body temperature rising to 90°C and accompanied by abnormal noise. Upon investigation, it was found that the bearing was stuck and the lubricating oil was dried up. At the same time, the current far exceeded the rated range. After replacing the bearing and adjusting the load parameters, the motor returned to normal operation. Subsequently, after standardizing load control, similar failures did not occur again.
Key Operation 2: Scientific Lubrication and Maintenance, Protecting the "Lifeline" of Bearings.
Bearings are the core rotating components of motors, and good lubrication is the foundation for their normal operation. Over 80% of bearing burnout failures are related to installation deviations, insufficient lubrication, or improper lubrication. If bearing damage is not addressed in a timely manner, it can further lead to serious failures such as rotor subsidence and rotor-stator contact, directly affecting the lifespan of the motor. Many operation and maintenance personnel fall into the misconception of "adding lubricating grease based on experience," which results in poor lubrication effects and accelerated bearing wear.
Scientific lubrication requires adherence to three major principles: selection, periodicity, and filling volume. Firstly, precise selection is crucial. Choose the appropriate lubricating grease based on the operating conditions of the motor (temperature, load, speed). For high-temperature and heavy-load conditions, it is recommended to use complex lithium-based grease or polyurea grease, with a dropping point of no less than 150℃. Avoid mixing different types of lubricating grease to prevent a decline in lubrication performance. Secondly, standardize the periodicity. Adjust the lubrication periodicity based on the operating duration and conditions of the motor. For small and medium-sized motors, replenish the lubricating grease every 2000-3000 hours of operation, and replace all the lubricating grease every 10000-15000 hours. For continuous operation and heavy-load equipment, the periodicity should be shortened to 3-4 months, and further shortened in humid and high-temperature environments. Thirdly, control the filling volume. It is advisable to fill the bearing with 1/2-2/3 of the internal space. Avoid overfilling, which can lead to poor heat dissipation and lubricating grease overflow, or underfilling, which can cause dry grinding of the bearing. Regularly check the wear condition of the bearing. If the bearing clearance is too large, the rotation is not flexible, or signs such as pitting and cracks are observed, it is necessary to replace the bearing with the same model in a timely manner to prevent the failure from escalating.
Practical Supplement: When installing bearings, it is necessary to ensure the alignment accuracy. Violent knocking is prohibited. It is recommended to use the hot assembly method (with the heating temperature controlled at 80-100℃). After assembly, radial and angular alignment deviations should be checked to ensure compliance with standards, avoiding inherent uneven stress on the bearings and potential damage hazards.
Key Operation 3: Strictly Control the Operating Environment and Ensure Cleanliness, Moisture Prevention, and Protection.
The operating environment of the motor directly affects its insulation performance and component wear. Issues such as dust accumulation, moisture corrosion, and poor ventilation can indirectly shorten the motor's lifespan. Dust clogging the ventilation holes can lead to poor heat dissipation, causing the motor to overheat. A humid environment can degrade the insulation performance of the windings, leading to winding breakdown and burnout. A corrosive environment can damage the motor housing and internal components, accelerating equipment aging.
The core of environmental control involves three key points: First, regular cleaning. Use dry compressed air (with a pressure not too high to prevent damage to components) to blow off dust, oil, and debris from the motor housing, vents, and winding surface. Avoid dust accumulation that could affect heat dissipation. Especially in workshops and machine rooms with high dust levels, increase cleaning frequency to ensure the cooling fins are unobstructed. Second, moisture and corrosion prevention. For motors used in humid environments, install moisture-proof heaters or apply insulating paint to the windings for enhanced protection against moisture. For motors exposed to corrosive gases or liquids, select an appropriate level of protection, promptly clean surface corrosion, and prevent component damage. Third, ensure proper ventilation. Ensure there are no obstructions around the motor and the vents are unobstructed. Check the cooling fan for integrity and replace it promptly if damaged to avoid overheating due to poor ventilation. In high-temperature environments, install auxiliary cooling equipment to reduce operating temperature.
Key Operation 4: Regular Inspection and Troubleshooting to Avoid Potential Failures in Advance.
Most motor failures are not sudden, but rather result from the long-term accumulation of minor hidden dangers. Regular inspection is crucial for timely detection of hidden dangers and early avoidance of failures, and it is also an important means to extend the lifespan of motors. In many operation and maintenance tasks, the misconception of "emphasizing emergency repairs and neglecting inspections" is widespread, leading to small hidden dangers developing into major failures. This not only increases maintenance costs but also shortens the lifespan of motors.
The inspection should follow the principles of "comprehensiveness, meticulousness, and closed-loop management", with a focus on four core areas: First, the temperature of the machine body. Use an infrared thermometer to detect the temperature of the motor housing and bearing end cap. During normal operation, the housing temperature should not exceed 75°C, and the bearing temperature should not exceed 80°C. If the temperature rises abnormally, issues such as overload, poor lubrication, or poor ventilation should be investigated. Second, the operating sound. Judge the operating status of the motor by listening to its sound. During normal operation, the motor emits a uniform and stable buzzing sound. If there is abnormal noise, noise, or vibration, it may indicate bearing wear, rotor imbalance, or winding failure, and the motor should be stopped immediately for investigation. Third, the electrical connection. Check whether the terminal blocks and cable connectors are loose, hot, oxidized, or have signs of ablation. Regularly tighten the wiring to avoid local overheating caused by poor contact, which can damage the winding. Fourth, the insulation performance. Regularly use a megohmmeter to test the insulation resistance of the winding. The insulation resistance of low-voltage motors should not be lower than 0.5MΩ, and high-voltage motors should meet corresponding standards. If the insulation resistance decreases, it is necessary to conduct drying treatment or replace the winding in a timely manner to prevent insulation breakdown.
Practical advice: Establish a patrol inspection ledger to meticulously record inspection times, motor operating parameters, identified issues, and their resolutions, forming a closed-loop management process of "inspection-investigation-treatment-re-inspection". For aged motors and heavy-load motors, it is necessary to appropriately increase the frequency of patrol inspections, with a focus on monitoring the status of critical components, ensuring early detection, early treatment, and early prevention.
Key Operation 5: Standardize start-stop operations to reduce mechanical and electrical shocks.
The start-stop process of motors can generate mechanical and electrical shocks. Frequent start-stops or non-standard start-stops can lead to increased bearing wear, accelerated aging of winding insulation, and potential damage to transmission components. Over time, this can significantly shorten the lifespan of the motor. Many operation and maintenance personnel engage in non-standard behaviors such as "frequent start-stops" and "start-stops with load," which pose hidden equipment risks.
Standardizing start-stop operations requires adhering to two core requirements: First, control the frequency of start-stop operations to avoid frequent motor start-stops within a short period of time. Generally, the interval between two motor starts should not be less than 3 minutes, and for high-power motors, the interval should be extended to 5-10 minutes to prevent excessive starting current from causing winding overheating. Second, standardize start-stop operations. Before starting, check the motor status to confirm that the load is at no load or light load. Turn off unnecessary loads to avoid starting with load. Observe the changes in current and temperature during startup. If there are difficulties in starting or abnormal current, immediately stop the machine for troubleshooting. When stopping the machine, first cut off the load power supply, and then turn off the motor power supply to avoid mechanical shock caused by sudden stopping. For high-power motors, devices such as soft starters and frequency converters can be used to reduce electrical shock and mechanical wear during start-stop operations.
Practical reminder: Due to frequent on-load start-stop operations, three asynchronous motors in a certain workshop experienced bearing damage and winding overheating issues in succession within a short period of time. After standardizing the start-stop operations and installing soft starters, the motor failure rate decreased significantly, and the service life was extended by more than 30%. This fully demonstrates the important impact of standardized start-stop operations on motor life.
Summary: An operation and maintenance closed loop effectively extends the lifespan of motors.
The key lies not in "post-event repair", but in "prevention beforehand, control during operation". The above five key operations, covering load control, lubrication and maintenance, environmental protection, regular inspection, and standardized start-stop procedures, span the entire process of motor operation and maintenance. These operations are simple and feasible, requiring no complex equipment, and can effectively reduce the motor failure rate.
It should be noted that motor operation and maintenance need to be flexibly adjusted according to their own working conditions. The focus of operation and maintenance varies slightly for different types and power levels of motors. It is recommended to develop a personalized operation and maintenance plan based on the motor manual and actual operating conditions, while establishing a comprehensive operation and maintenance ledger to form a closed-loop management. Only by adhering to scientific and standardized operation and maintenance practices over the long term can we effectively extend the lifespan of the motor, reduce operation and maintenance costs, ensure stable equipment operation, and provide reliable power support for production and daily life.
Hengda Motor has always been dedicated to the research, development, production, and service of various motors. With advanced technology and equipment, lean manufacturing processes, reliable product quality, and satisfactory after-sales service, the company provides customers with professional motor solutions that are more suitable, creating greater social value.
