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Induction coil burnout cause analysis and maintenance method

The reason why the inductor is burnt out can be said to be very much. We can consider prevention from the following factors:
1. The design margin of the inductor coil is not enough; the manufacturer does not leave a certain room for cost saving. The design margin is originally a part of the design that takes into account various factors in the design process and deliberately designs.
2, the quality of the enameled wire; manufacturers in order to reduce the cost of production, the use of temperature-resistant enameled wire below 130 ° C ~ 150 ° C.
3, the temperature rise of the inductor coil; generally speaking, the design requirements of the inductor coil are below 60K, the heat resistance of the polyester enameled wire should be 155 °C, and some manufacturers reduce the number of inductor turns in order to reduce the cost. Increase the temperature of the inductor coil to 75K~90K, so that the inductor coiled wire is working at high temperature for a long time. Once it is overloaded for a long time, it may cause poor contact of the conductive part and increase the contact resistance, which will greatly reduce the inductance. Coil insulation strength.
4. The reaction force between the suction force of the induction coil; when the voltage is low, the suction will become difficult, the operation time of the induction coil is long, and the time for the induction coil to withstand the strong current becomes longer, and the inductance coil is heated more, and at the same time The suction is more obvious and the suction is more difficult until it can not be sucked. When the inductor coil operates at a high temperature, the resistance increases and the current will become very large.
5. The working voltage range of the product design is not wide enough. Once the voltage is between 80% and 85%, the hot state may not be absorbed. When the voltage is higher than 120%, the inductor coil will easily overheat.
6. The control process is not strict or out of control; during production, the inner layer of the winding of the inductor coil is not sufficiently immersed in the paint, and the drying is not thorough. It is easy to cause poor soldering of the lead wire joint and incomplete insulation, resulting in inter-turn and inter-layer Short circuit and loss of insulation.
7. There is a shortage of the winding process of the inductor coil; when the winding machine is in production, the winding tension should not be too loose or too tight, otherwise the enameled wire will be elongated, resulting in partial insulation withstand voltage drop.
8. Before the input of the inductor coil, because the weather is humid, rainy, and the humidity is 80%, it is easy to cause moisture to intrude into the inside of the inductor coil, resulting in moisture in the insulation part.
9. In the process of storage and transportation of the induction coil, if the error is improper, the impurities such as moisture and grease will be mixed, and the insulation strength will be greatly reduced.
10. In the process of use, the insulation part of the inductor coil is damaged or mechanically damaged, causing the inductor coil to short-circuit or hit the ground. Then the inductor coil generates a large short-circuit current, causing the temperature to rise sharply and transfer the heat to Near the line, it will eventually burn the entire coil.
11, the human cause part; when the user is unfamiliar with the use of non-inductive coil, often the voltage regulation is not correct; the installation process is poor, the inspection of the inductor coil is not careful, resulting in the inductor coil mixed with other impurities, operation and maintenance is not in place The relevant use technology has not been strictly implemented. During the period from installation to burnout, most of the inductor coils have not undergone routine routine maintenance and dirt treatment, resulting in poor heat dissipation conditions of the inductor coil and burning.
12, lightning strike; the general and other electronic components of the inductor coil were previously installed in the equipment, the organic rate line was struck by lightning, and the surge voltage on the inductor winding will be more than several dozen times higher than the rated voltage, then the inductor coil is struck by lightning. Damage will be difficult to avoid.
The above causes the inductor to burn out, and can be used continuously by simple repair. The method is to rewind the coil, as long as the number of turns is not particularly large, the short circuit is at the end of the coil, and the rest of the inductor is intact, then the damaged part can be removed, leaving the rest Continue to use, which has little effect on the performance of some of the inductors.
In fact, some accidents of inductive coil burnout can be avoided. Some of them can be effectively eliminated in the bud as long as they are operated according to the production requirements and strict quality requirements.

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