There are many reasons for the failure of high voltage motors. Therefore, it is necessary to classify and analyze the common faults of high-voltage power. At the same time, it explores targeted and clear fault handling methods for various faults, and puts forward effective preventive measures to eliminate the faults of high-voltage motors in time, so that the failure rate of high-voltage motors is reduced year by year.
Motor cooling system failure
1. Failure analysis
Due to production requirements, high-voltage motors are frequently started, with large vibrations and large mechanical impulses, which can easily lead to faults in the motor circulating cooling system, mainly including the following types:
First, the damage to the external cooling pipes of the motor leads to the loss of cooling medium, which reduces the cooling capacity of the high-voltage motor cooling system, hinders the cooling capacity, and causes the motor temperature to rise.
Secondly, after the cooling water deteriorates, the cooling pipes are corroded and blocked by impurities, causing the motor to overheat.
Third, some cooling heat pipes have higher requirements on heat dissipation function and thermal conductivity. There are voids between objects between different materials due to different degrees of shrinkage. Oxidation and rust appear at the combined position of the two, and the cooling water penetrates into it, which will cause the motor to "fire", and the motor unit will automatically shut down, resulting in the motor unit not working normally.
Motor rotor failure
1. Failure analysis
In the process of starting and overloading the motor, under the influence of various forces, the short-circuit ring of the rotor inside the motor is welded to the copper strip, which causes the copper strip of the motor rotor to loosen slowly. Generally, the end ring is not forged from a single piece of copper material. The welding seam is poorly welded, and it is easy to crack due to thermal stress during operation. The loose fit between the copper bar and the iron core causes the copper bar to vibrate in the groove, which may cause the copper bar or the end ring to break. In addition, if the installation process is not carried out in place, the surface of the wire rod will be slightly roughened. If the heat cannot be dissipated in time, it will seriously lead to expansion and deformation, resulting in increased rotor vibration.
2. Repair method
The premise is to detect the high-voltage rotor electric welding points, carefully clean the impurities in the iron core groove, and specifically detect whether the strips, cracks, etc. can be broken down. Use the copper material to weld all the nuts at the fracture of the electric welding, and then use them routinely. Perform minor inspections of rotors and windings with a focus on prevention. Once it is found that it needs to be replaced in time, it will avoid serious burns to the iron core. Regularly inspect the core close to the bolts, re-install the rotor, and determine damage to the core if necessary.
Repair and maintenance methods
According to the conditions of the construction site, first wrap the motor with insulating tape to bypass the high-voltage lead section. Depending on the condition of the repair electrician, the electrician will first wrap it with insulating tape.
The frequently used "hanging handle" process directly lifts the edge of the upper slot of the faulty inductor coil 30 to 40 mm away from the inner side wall of the stator core of the motor, and finds a way to stabilize it. Use a simple baking and pressing fixture to initially clamp the newly bound insulation resistance components, use powder mica tapes to half-fold the upper vertical line segment to ground insulation resistance for ten to twelve layers, and then bind the two ends of the adjacent slot inductance coil for insulation resistance to ground. Resistor and inductance coil beam ends are coated with high-resistance semiconductor material paint, and the length of Xu brush is 12 mm. Try to complete the electric heating and water cooling twice each. Tighten the membrane screw again before the second electric heating.
备案号：