In the agricultural production and processing, the use of electric motors is the most. Among them, the burning of the motor is most common. This is a big problem for farmers. The key to solving this problem, in addition to using the necessary technical protection, the most effective method of prevention is to correctly maintain and use the technology. Practice has proved that the following methods are effective. First, start the equipment technology state should remain intact Motor starter equipment state of technology is directly related to the ability to start smoothly, practice shows that the vast majority of burned motors are not started and burned. If the start-up equipment has a poor state of technology, the lack of phase starts; the contacts of the contactor pull the arc, causing the voltage and current to change dramatically. The best way to keep the equipment in a good technical condition is to do inspections, cleaning and fastening work. If the contacts of the contactor are not clean and the oxidative ablation is serious, the contact resistance will increase, causing heat and ablation of the contacts, thus forming a phase-missing operation and burning the motor windings; the contactor suction coil core has rust and dust , It will make a strong noise absorption and increase the coil current until the coil is burned. Therefore, the electrical control cabinet should be set in a dry, ventilated and easy to operate position; also regular dust removal, cleaning contacts; coil core to increase rust prevention measures; often tighten the connection parts; check contactor contacts, ensure Good contact, institutional actions should be flexible and accurate, these are the inevitable conditions to ensure smooth start-up. Second, keep the motor clean and a good cooling environment In the motor inlet, must always be kept clean. There must be no dust, oil, water stains or other debris in the surrounding of the air inlet to prevent such things from inhaling into the motor to form a short circuit medium or damage the motor winding insulation layer; or to block the ventilation cooling of the motor and increase the temperature, resulting in burn. Third, to maintain the motor under rated current work agricultural motor overload operation, the main reason is that the drag load is too large; voltage is too low; or dragged by the mechanical locking caused. When the motor is running in an overload state, the motor speed drops, the current increases, the temperature rises, and the winding coils overheat. If the overload time is slightly longer, the overload motor absorbs a large amount of active power from the power grid, and the current increases rapidly, and the temperature rises accordingly. Motor insulation materials that operate at high temperatures tend to age and fail to burn the winding coils. This is the main reason for burning a motor. Therefore, we must always pay attention to checking whether the transmission of the unit is flexible and reliable; checking and adjusting the tightness of the transmission belt at any time to prevent jamming is one of them. The second is to pay attention to the operating machinery do not overload for a long time. The third is to keep the voltage of the power grid stable, and in particular it is not allowed to operate at low voltage, so as to ensure that the motor operates normally at the rated current. Fourth, to maintain the current balance between three agricultural stepping motor, the difference between the current value of any of the two and the other two-phase current shall not exceed 10%, which is a necessary condition to ensure the safe operation of the motor. If this difference exceeds 10%, it means that the motor has failed and must be shut down immediately. After the cause is determined and eliminated, it can continue to work. Otherwise, the fault will rapidly expand until the motor is burned. Fifth, keep the motor temperature and temperature rise In the normal range of the motor operation, we must always check the temperature of the bearing, stator, housing and other parts for any abnormalities, especially for the motor without overload protection, monitoring the temperature is more important. If the bearing lacks oil or is damaged, it will inevitably cause the temperature to rise. If the temperature of the body increases near the bearing, it is necessary to immediately stop the bearing inspection. The bearing can be refueled first. If it is still invalid, the bearing identification should be removed. If the rolling elements, raceway surface cracks, scratches or damage, or the gap becomes larger, the inner ring in the bearing rotation, any one, should replace the bearing. Otherwise, continued use will cause further damage to the bearings, resulting in major accidents such as the collapse of the frame and the burning of motor brooms. Monitoring the temperature or temperature rise of the motor can be monitored by the following simple method: insert a thermometer in the hole of the motor and plug it with a cotton mass to monitor the change of motor temperature at any time. The temperature difference is usually 1°C. Sixth, timely detection and processing of motor abnormality in the operation of the motor should be no vibration, noise and odor. If vibration occurs, the axis of the load connected to the motor will increase, and the load will increase. As a result, the load current will increase, causing the temperature to increase and the motor to be burned. Therefore, always check the vibration of the anchor bolts, motor end caps, bearing glands, etc. must not be loose, the connection device must be reliable, especially for high-power motors, must be promptly found to eliminate. Noise and odor are important signs of abnormal operation of the motor and are also precursors of major accidents. They must be discovered in time, and the causes must be eliminated immediately. Otherwise, the timing will be delayed, the scope of faults will be expanded, and a serious accident that burns the motor will occur. VII. Before starting, it is necessary to carefully check and correct operation. 1. Before starting, check whether the line voltage is normal. If it is too high or too low, it should not be started. Normally, it should not exceed 10% of the rated voltage to start. 2. Before starting, check the work machine for blocking, especially the drive belt should not be too tight or too loose, and the nut and key of the coupling should not be loosened. 3, remove debris. Remove dirt from the motor, nearby debris, and stacking flammables and explosives. 4, limit the number of starts. The number of consecutive motor starts shall not exceed 3-5 times (idle state); it shall not be started more than twice after the machine is shut down for a short period of time. Otherwise, it is easy to burn the motor. 5, multiple motors start operation. When it starts, it should be started one by one in a sequence, and several stations should not be started at the same time. 6, reverse processing. When the startup is reversed, it should be stopped immediately, and then any two-phase power cords will be turned on before starting.
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