Small irrigation pump is widely favored by many farmers, due to its low price and easy operation. In recent years, the social retention volume of small irrigation water pumps in the world has increased substantially. We found that the issue of inappropriate power match for pump is common in rural areas, it’s lead to either waste of power or lack of power. So, how to match power for small irrigation pump?
There are two types of power for small irrigation water pumps: electricity power and heat power. The former is a three-phase or single-phase motor, the latter is a diesel engine. After selecting the small water pump model, you should choose the power according to the following requirements.
1. Small Irrigation Pump Motor Type Selection
According to the local power supply situation, areas with reliable power supply should choose electric motor, generally choose squirrel-cage model. Only when the capacity of the power grid is small, which is not enough to ensure start the cage motor, then consider the choice of winding type.
Adopt a protective type in places where is dry or there is not much dust. Adopt close type motor in dusty or water splashing places : use sealed type motor for immersion work. When the pumping load of the pump is continued evenly. Suggest use a continuous working motor type, and its speed should be as close as possible to consistent with the pump, easy to start directly. Otherwise choose a speed closer motor to indirect transmission.
2. Power selection
Strictly speaking, the selection of the power machine for the water pump requires scientific calculation. But, you can choose electric motor for small irrigation water pump base on past experience. Generally, the power of the electric motor should be equal to 1.0~1.3 times of the power required by the water pump. and the internal combustion engine should be equal to 1.3 ~1.5 times of the power required by the water pump. If it is too large, it will waste energy, and if it is too small, it will easily be unable to move or overload the power machine.
If you have bought some power equipment beforehand, you should give full play to the role of the existing power machine. When purchasing a new irrigation water pump, we should try our best to be able to match the original power machine, except for special needs. Generally, it is not necessary to equip each machine with a separate power machine, which will cost too much and management is inconvenient. In a fixed unit, the Small Irrigation pump electric motor can be used in the range of 75% to 100% of the rated power: A diesel engine with a full-standard speed governor can use under the reducing speed and power within its speed adjust range.
3.Rated speed selection
The rated speed of the small water irrigation pump motor is determined according to the requirements of the water pump. However, the synchronous speed of the asynchronous motor is usually not less than 500 revolutions per minute. Therefore, the pump that requires low speed must be equipped with a deceleration device. Because the asynchronous motor under the same power condition, the more lower its synchronous speed is, its electromagnetic torque is more larger, its volume is more larger, the weight is more heavier, and the price is more expensive. Thus, choose high-speed motor is more economical. So, in general, try to use high-speed asynchronous motors, such as the number of magnetic pole pairs P=I or 2.
4.The rated voltage of the selected motor
The rated voltage of the selected Small Irrigation Pump motor should be consistent with the voltage of the power supply grid. The voltage applied to the three-phase asynchronous motor will work normally within the range of +10% to 5% of its rated voltage. In the rural low-voltage power grid, the voltage is 220/380V. Therefore, small and medium asynchronous motors used in rural areas are all low-voltage, and usually single-phase motors have a rated voltage of 220V. Three-phase motor rated voltage 380V, △ connection method. This three-phase motor has two advantages. One is that it can be started by y/A step-down. Because when the rated power of the motor reaches 1/3 of the transformer capacity. This motor must be started with reduced voltage. The second is a dual-purpose machine. The method is to connect the windings of the j-phase asynchronous motor into a star shape connected to 380V power supply. At this time, the power of the motor is about 34% of the rated power. Finally, it needs to be emphasized that, you should choose three-phase motors as long as there is a three-phase power supply in rural areas This is because three-phase asynchronous motors have smaller size and weight compared with single-phase asynchronous motors under the same power conditions, its with more lightweight, low vibration, low price and low power consumption.