Analysis of common faults of three – phase asynchronous

With the power in the production and life of large-scale use of three-phase asynchronous motor, the main form of the motor for its convenience, maintainability and high cost performance in industrial and agricultural production has been widely used. To protect the normal use of three-phase asynchronous motor need to sum up the long-term use of three-phase asynchronous motor fault characteristics on the basis of good for three-phase asynchronous sawing machine motor maintenance. So that the three-phase asynchronous motor can be used normally to ensure the normal operation of production work.
1. Three-phase asynchronous motor common mechanical failure analysis
Three-phase asynchronous motor fault according to its common characteristics can be divided into two major aspects of mechanical, electrical failure. The three-phase asynchronous motor’s mechanical failure mainly has the following several kinds: The bearing damage, the stator iron core surface damage, the motor temperature rise is too high, the winding burns and so on the question. The bearing wear and tear which is the highest frequency of three-phase asynchronous motor failure.
Three-phase asynchronous motor due to the need for a long time of rotation, and changes in load force on the three-phase asynchronous motor bearings exert a greater impact. Three-phase asynchronous motor bearings in a long time after the use of a variety of problems, it is necessary in the use of three-phase asynchronous motor to strengthen the three-phase asynchronous motor bearing part of the inspection to protect the normal use of three-phase asynchronous motor. In the use of three-phase asynchronous motor to strengthen the observation of the bearing, through the operation of three-phase asynchronous motor in the use of smell, listen to check the way for the three-phase asynchronous motor fault detection and detection. In the course of three-phase asynchronous motor operation found abnormal sound when the motor can be analyzed from the following points, when the three-phase asynchronous motor during cnc table the operation of the bearing part of the Gulu Gulu voice can be identified when the three-phase asynchronous motor bearing oil . And if the three-phase asynchronous motor running when the bearing part of the sound appears discontinuous stems can be identified as three-phase asynchronous motor shaft ring rupture, the need for three-phase asynchronous motor bearing part of the timely replacement to ensure that three-phase The normal use of asynchronous motor. When the bearing part of the three-phase asynchronous motor contains sand or mild wear and tear, the three-phase asynchronous motor in operation will appear as a slight noise.
When it is determined that there is a problem in the bearing part of the three-phase asynchronous motor, it is necessary to check the bearing of the three-phase asynchronous motor and dismantle the bearing gland of the three-phase asynchronous motor. First check the inner and outer rings of the rolling element of the three-phase asynchronous motor Whether the bearing is damaged, corrosion and dent, etc., in the completion of the bearing appearance of the test to determine no significant damage to the situation, the use of cleaning gasoline to clean the bearings to remove the bearings contained in lubricants and other impurities, And then use the hand toggle bearing outer ring, check the bearing operation, such as bearing a good bearing outer ring should be smooth, feel the bearing through the hand during the operation of whether there is vibration and stuck phenomenon, and stop the outer ring When the bearing Plate Notching Machines is not obvious the phenomenon of retrogression, if there is an obvious problem bearing has been not suitable for continued use should be replaced. If one hand stuck the bearing outer ring, one hand pinch the inner ring, forced to promote, if the bearing to promote more easily but bearing wear more serious, then the bearing can not continue to use need to be replaced.
In the three-phase asynchronous motor bearing replacement needs to be removed according to the type of bearing to buy and replace. In the three-phase asynchronous motor bearing assembly, you can use the bearing heater or transformer oil boiling way to heat the bearing, when the bearing heated to 80-100 ℃, the use of similar inner diameter and bearing steel pipe to Bear the inner ring to the bearing ring, until the bearing inner ring of the percussion sound in real time, you can think that the bearing hit in place before the assembly of the motor shaft to be carefully cleaned, and pay attention to bearings and bearings The installation of the oil tank, grease assembly attention to the amount, avoid too much or too little to avoid three-phase asynchronous motor movement bearing overheating.
2. Three-phase asynchronous motor common electrical fault analysis
Three-phase asynchronous motor common electrical faults are: three-phase current imbalance, stator windings phase operation, three-phase asynchronous motor electrical control and other issues, such as three-phase asynchronous motor fuse, contactor In place or other electrical damage will cause three-phase asynchronous motor can not start or suddenly stop running seriously affect the normal use of three-phase asynchronous motor.
2.1 Three-phase asynchronous motor three-phase current imbalance fault analysis and treatment
Three-phase asynchronous motor three-phase current imbalance of the main reasons are: 1) three-phase asynchronous motor rewinding stator three-phase winding turns are not equal. 2) three-phase asynchronous motor stator windings first terminal is wrong. 3) three-phase asynchronous motor power supply voltage three unbalanced. To solve the three-phase asynchronous motor three-phase current imbalance problem, you can rewound the stator windings, check and correct, measure the power supply voltage and other methods to be eliminated.
2.2 Three-phase asynchronous motor phase failure analysis and treatment
Three-phase asynchronous motor caused by the lack of phase running the main reasons are: 1) a fuse fuse. 2) The problem such as breakdown blows. Three-phase asynchronous motor failure in the main reason is due to the motor’s main circuit single-phase grounding or phase short circuit caused by the three-phase induction motor to ensure the normal use of the need to select the appropriate ambient conditions, the motor and the correct low-voltage electrical and Line, to ensure the normal use of three-phase asynchronous motor. In the three-phase asynchronous motor main circuit caused by the lack of phase operation of the main reasons are: 1) to control the three-phase asynchronous motor contactor static and dynamic contact wear serious, resulting in bad contactor. 2) three-phase asynchronous motor operating conditions are more harsh, contact the contact oxidation. 3) control of three-phase asynchronous motor contactor selection is unreasonable, making the three-phase asynchronous motor bimetal burned. 4) the contactor or the motor into the line side of the connector is not tight or loose connectors caused by wire blowing. To deal with this failure can be from the following aspects: 1) do a good job for the three-phase asynchronous motor inspection and maintenance on a regular basis, especially for some of the more harsh conditions of the three-phase asynchronous motor needs of vulnerable components on a regular basis . 2) Select the appropriate thermal relay. 3) In the three-phase asynchronous motor wire and cable construction process to the main line safety, to avoid wires, cables breakage, scratches and other issues.
2.3 Three-phase asynchronous motor in the fuse melt non-fault
In the three-phase asynchronous motor in the installation of fuse-links, fuse-mounted installation of poor contact or fuse installation of excessive force caused by the fuse-body damage, fuse-link selection will result in three-phase asynchronous motor fuses non-fault Of the fuse so that three-phase asynchronous motor can not be used normally. To solve this problem, the need to analyze the capacity of three-phase asynchronous motor based on the size of the rated current of the motor, under normal circumstances, the size of the current capacity of the fuse-link selection of three-phase asynchronous motor rated current 2 times , At the same time in the three-phase asynchronous motor fuses installed to ensure good contact between fuse-links and fuse blocks to avoid short-circuit and other problems. After the installation is complete, use the multimeter to test the electrical installation of the three-phase asynchronous motor to ensure the installation quality of the three-phase asynchronous motor.
3. Do a good job of three-phase asynchronous motor energy-saving transformation
Three-phase asynchronous motor is the most important use of rotating magnetic field to drive the rotor to rotate. In the three-phase asynchronous motor can be connected through the capacitor, the same period compensator and SCR voltage regulator devices such as energy-saving three-phase asynchronous motor through the control end of the three-phase asynchronous motor and the capacitor can save reactive power, So as to improve the three-phase asynchronous motor power factor, and the implementation is relatively simple, but the use of this method may occur oscillation. While the use of synchronous compensator is the most important way to adjust the reactive and active phase angle to achieve the purpose of improving the power factor. The most important thing is the use of thyristor voltage on the motor side with the load to automatically adjust.

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