The motor is the starting core of various industrial machines. It is as important as the human brain. Once a problem occurs, it will cause damage to the machine, which will affect the production process. Therefore, it is necessary to regularly check whether the motors of important industrial machines are normal. The failure of most motors is mainly due to the problems of the motor stator insulation. How to troubleshoot and solve the motor stator insulation problems can be solved by the following methods.
First we understand the insulation of the synchronous motor windings. Synchronous motor winding insulation includes inter-strand, brake, row, and layer. Insulation members for supporting or fixing at various ends, and insulation of connection wires and lead wires. Different insulation materials or process methods constitute different insulation structures. The insulation structure mainly plays a role of isolating electricity. In long-term operation, due to the effects of electricity, heat, machinery and different environments, the insulation gradually ages, making the motor unable to operate safely. Therefore, the absolute insulation is important to determine the operation of the motor. factor.
The stator insulation problem of synchronous motors is manifested in two aspects: on the one hand, the stator insulation is damaged, and it is manifested as local and coil insulation damage. Damage to the ground insulation in the coil, damage to the slot exit of the coil, damage to the coils on the end ferrules, and phase-to-phase insulation damage; on the other hand, the performance of the insulation has deteriorated to the extent that it cannot meet the basic requirements for certain operations. The degradation of insulation performance is mainly manifested in the reduction of stator insulation resistance and absorption ratio. It also shows that the leakage current value is too high during DC withstand voltage, three-phase imbalance, DC withstand voltage breakdown, AC withstand voltage breakdown, etc. .
The conventional test method is to measure the stator insulation resistance and absorption ratio with a megohmmeter. This is the most direct inspection method commonly used, and the DC withstand voltage leakage test can further check and find insulation defects. In most cases, the insulation can be broken down. Find or find defects before.
If the above two methods have not found a problem, you can use the AC withstand voltage test. Its test voltage is consistent with the frequency of the working voltage waveform. It is a reliable method to check and test the insulation of the motor. The decrease in insulation performance is generally divided into a general decrease in the insulation performance of the motor coil and a partial, individual coil performance decrease.
The problem of finding the insulation point of the motor is obvious in the accident state. In order to ensure the normal operation of the motor, please find the fault point according to the above methods. The insulation problem seriously affects the operation of the unit. If it is not handled properly, it is often the condition that caused the accident.
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