The fundamental difference between high and low voltage motors lies in the difference in rated voltage of the motors. It is precisely because of the difference in rated voltage that the motor components and materials are quite different.
The difference in electromagnetic wires. Due to the large difference in voltage between high and low voltage motors, the electromagnetic wire types and insulation structures used are quite different; low voltage motors use more enameled wires, with round wires as the main type, and larger motors also use enameled flat wires and bare copper flat wires; the rotor part of high voltage motors is not much different from low voltage motors, but the stator winding wires must use mica wires or silk-covered wires with higher insulation performance, and the specific insulation level is directly related to the rated voltage of the motor; the electromagnetic wire type of high voltage motors is flat wire, mainly to facilitate coil forming and later coil insulation wrapping.
The winding insulation structure is different. Low-voltage motors use either loose-embedded windings or formed windings. No insulation material is wrapped around the electromagnetic wires. Only necessary slot insulation and interphase insulation materials are added during the embedding process. High-voltage motors need to wrap several layers of mica insulation and anti-corona materials around the outside of each coil. Finally, the finished coils are placed directly into the core slots. In principle, no other insulation materials are added, but necessary gap filling is required.
The difference in lead wires. The lead wires used by high-voltage and low-voltage motors have different voltage levels. In comparison, the lead wires of high-voltage motors have thicker insulation sheaths and thinner wire cores; while the insulation sheaths of low-voltage motors are thinner, but because the current of low-voltage motors is larger, the wire core area is larger.
Different wiring systems. Due to the difference in electrical clearance and creepage distance between high and low voltage motors, the terminal posts of high voltage motors must have an insulating sheath, the distance between the posts is farther, and the terminal box is also significantly larger. Therefore, the rated voltage of the motor can be basically distinguished from the wiring system.
In view of the above main factors, the power of high-voltage motors is relatively large, and motors with too small power are neither necessary nor convenient to be made into high-voltage motors; similarly, low-voltage motors are mostly small-power motors. When the power is too large, the electromagnetic wires, lead wires and distribution facilities are difficult to implement. Therefore, when the power reaches a certain value, they will be designed as high-voltage motors.
Post time: Mar-05-2025