Core influences on three-phase motor speed

Relationship between the number of magnetic pole pairs and rotational speed

       2-pole motor: synchronous speed 3000r/min, actual about 2850r/min, suitable for high speed equipment (e.g. centrifugal fan, small water pump) 17.

       4-pole motor: synchronous speed 1500r/min, actual about 1450r/min, general-purpose options (such as conveyor belts, general machine tools) 19.

       6/8-pole motor: synchronous speed 1000r/min/750r/min, large torque, suitable for high load equipment (e.g. cranes, sewage pumps, elevators) 16.

   Power frequency and speed regulation demand

       The frequency of our power grid is fixed at 50Hz, and if speed regulation is required, it needs to be realized by frequency converter (variable frequency speed regulation) or variable pole speed regulation. Frequency converter can adjust speed steplessly, which is suitable for precision control scenarios (e.g. CNC machine tools, centrifugal pumps)37.

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