Measures to improve the insulation quality of explosion-proof motors include the following aspects
1. Improve the quality of the iron core: At present, the insulation specifications of the explosion-proof motor industry are basically unified. The selection of materials and the design of the insulating structure are not very different from one manufacturer to another. But compared with the international, there is still a gap. The main reason for the difference is the quality of the iron core, which limits the thickness of the insulation.
2. Reasonable use of insulating materials: polyester film and polyimide film have high compressive strength, but they are not scratch-resistant, and they cannot be next to the iron core. When two layers of slot insulation are used, they should be placed on the inside. However, in order to improve the insulation strength at the notch, the effect is not obvious if they “roll up the sleeves” at the notch and then lean against the iron core at the notch. It is appropriate to roll up the outer NMN or DMD sleeves.
3. Withstand voltage test: For the 6kv explosion-proof motor, the test voltage of molding and VPI is 1.3kv during the finished product test. However, in the process from white embryo to finished product, the test voltage of each stage is gradually reduced from high to 1.3kv; while VPI should be the opposite, from low to 1.3kv. Because for the VPI process, the completion of the dipping and drying is regarded as the completion of the insulation treatment.
4. At present, the main insulation of domestic high-voltage motor coils adopts three kinds of mica tapes and two kinds of processes-molding and VPI.
5. When the high-voltage explosion-proof motor adopts the VPI process, because the white embryo coil is embedded, there is no need to insert the wire gap. However, it is more appropriate to use a layer of 0.1mm thick NMN as the slot insulation to avoid the main insulation of the coil being scratched by the iron core when the wire is embedded.
Post time: 2022-02-21