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How To Choose The Motor Reasonably By The Motor Power And Torque Calculation Formula Nov 18, 2019

We know that no matter whether the motor is too large or too small, an abnormality will occur. If the motor power is too small, the phenomenon of “small horse-drawn cart” will occur, causing the motor to be overloaded for a long time, causing its insulation to be damaged by heat, or even the motor being burned. If the motor power is too large, there will be a phenomenon of “large horse-drawn car”. The output mechanical power cannot be fully utilized, and the power factor and efficiency are not high, which is not only unfavorable to the user and the power grid, but also causes waste of electric energy.

Therefore, the choice of motor power should be selected according to the power required by the production machinery, and the motor should be operated under the rated load as much as possible. To properly select the power of the motor, the following calculations or comparisons must be made.

For, calculate the power required by the motor according to the following formula:


P=calculated power KW, F=required tensile force N, working machine linear speed M/S

For constant load continuous operation, the power of the required motor can be calculated as follows:


Where n1 is the efficiency of the production machine; n2 is the efficiency of the motor, ie the transmission efficiency.

When selecting a motor, the rated power of the selected motor should be equal to or slightly greater than the calculated power.