One, the main basis for the selection of motor pump
(1) According to the mechanical load nature and production process of motor starting, braking, operation, speed regulation and other requirements, select the motor type.
(2) According to the requirements of load torque, speed variation range and starting frequency, consider the temperature rise limit, overload capacity and starting torque of the motor, reasonably select the motor capacity, and determine the cooling and ventilation mode.
(3) According to the environmental conditions of the use place, such as temperature, humidity, dust, rain, gas, rot and turbidity, flammable and explosive gases, etc., consider the necessary protection mode and the structure of the motor, determine the explosion-proof grade and protection grade of the motor.
(4) Determine the voltage level of the motor according to the enterprise's power grid voltage standard and requirements for power factor.
(5) According to the highest speed of the production machinery and the performance requirements of the transition process of the electric transmission speed control system, as well as the complexity of mechanical deceleration, select the rated speed of the motor,
In addition, the selection of motor must meet the requirements of energy saving, considering the reliability of operation, supply, the versatility of spare parts, the difficulty of installation and maintenance, product price, construction cost, operation and maintenance costs, etc.
Second, the choice of motor type
The choice of motor type should be considered from the two perspectives of load characteristics and energy saving.
The load characteristics of the standby pump are as follows: positive displacement pump including diesel pump. Its "rotational speed - torque" characteristic belongs to constant torque characteristic; Centrifugal pump and other vane pump is a square torque characteristic, that is, the torque increases with the increase of speed in a square relationship
