Some multi-stage centrifugal pumps users think that the […]
Some multi-stage centrifugal pumps users think that the lower the pumping lift, the smaller the motor load. Under the misunderstanding of this misunderstanding, when the pump is purchased, the lift of the pump is often selected very high. In fact, regarding the centrifugal pump, when the pump type is determined, the power consumption is proportional to the actual flow of the pump. The flow rate of the pump will decrease with the addition of the lift, so the higher the lift, the smaller the flow and the smaller the power consumption. Conversely, the lower the lift, the greater the flow and the greater the power consumed.
Therefore, in order to avoid motor overload, it is usually required that the pumping practice of the pump should not be less than 60% of the nominal head. Therefore, when the high lift is used for pumping with low lift, the motor is simply overloaded and heated, and the motor can be burned when it is severe. If it is used in an emergency, it is necessary to install a gate valve for regulating the amount of water on the outlet pipe (or plug the small outlet with a wood number) to reduce the flow and avoid overloading the motor. Pay attention to the temperature rise of the motor. If the motor is overheated, turn off the flow of the small outlet or shut down. This is also a simple misunderstanding. Some operators think that blocking the water outlet and forcing the flow to be reduced will add motor load. In fact, on the contrary, the standard high-power centrifugal pump drainage and irrigation unit is equipped with a gate valve on the outlet pipe. In order to reduce the motor load when the unit is started, the gate valve should be closed first. This is the reason after the motor is started and then gradually open the gate valve.