What is motor insulation made of?

In electrical equipment such as stepper motors, closed-loop motors, and servo motors, equipment using different insulation materials has different abilities to withstand high temperatures. Therefore, general motors have a maximum allowable temperature for their operation. Now let’s take a look at insulation materials and the temperatures they withstand.

Class A insulation materials: including impregnated cotton yarn, silk, paper and other organic fiber materials, as well as enamel on ordinary enameled wires, etc., and are currently only used on transformers. The maximum allowable operating temperature is 105°C. The temperature rise of the wire group is 60℃, and the performance reference temperature is 80℃.

Class B insulation materials: including mica, asbestos, glass fiber and other organic matter; materials and compositions made of organic paint or resin with improved heat resistance as a binder; enamel on polyester high-strength enameled wire; maximum allowable work The temperature is 130℃. The temperature rise of the wire group is 80℃, and the performance reference temperature is 100℃. It has good heat resistance, solvent resistance, adhesion performance, high mechanical strength, etc., and is suitable for small ordinary motors, electrical appliances, instruments, and telecommunications materials.

Class C insulation materials: including mica, quartz, glass, etc.; asbestos, glass fiber fabrics or their products treated with silicone resin, polyimide impregnating paint, etc. with particularly excellent thermal stability; polyimide based Enameled wire enamel, polyimide film, etc., Class C insulation grade is an insulating material with higher requirements and is being promoted and used in production. Its maximum allowable working temperature has not yet been determined, but it is probably above 180°C.

Class F insulation materials: including mica, asbestos, glass fiber and other inorganic materials, made of synthetic resin paint modified with silicone organic compounds, or alkyd, epoxy and other synthetic resins whose heat resistance meets this requirement as a binder. Material or its composition, the maximum allowable operating temperature is 155°C. The temperature rise of the wire group is 100℃, and the performance reference temperature is 120℃. Its characteristics are that it has good heat shock resistance, mechanical and electrical properties and high softening temperature. It is suitable for high temperature resistant electronics, instruments, meters and telecommunications equipment.

Class H insulation materials: Materials including silicone organic matter and inorganic materials such as mica, asbestos, glass fiber, etc., with silicone organic paint as a binder. The maximum allowable working temperature is 180°C. The temperature rise of the wire group is 125℃, and the performance reference temperature is 145℃. It is characterized by excellent friction, heat and solvent resistance. Its scope of application is general motors, transformers, four-way valves, igniters, automotive relays, etc.

Class E insulation materials: including films made of polyester resin, epoxy resin, triacetate fiber, etc., polyvinyl acetal, enamel on high-strength enameled wire, etc. The maximum allowable operating temperature is 120°C. The temperature rise of the wire group is 75℃, and the performance reference temperature is 95℃.

In addition, it should be noted that the insulation level and insulation temperature resistance are closely related, because the higher the temperature, the worse the insulation performance of the material will be. Therefore, different grades of insulation materials have a maximum allowable operating temperature, and within this temperature range, they can be used safely. If the working temperature of the insulating material exceeds its own insulation heat-resistant temperature, the insulating material will age rapidly and become unusable, which may also cause safety hazards.

Article source: https://article-realm.com/article/Product-Reviews/55617-What-is-motor-insulation-made-of.html