What may cause an increase in pump motor power consumption?

An over-tightened pump packing gland can create excessive friction and resistance within the pump. When the packing gland is tightened beyond what is necessary, it can lead to increased wear on the pump components, ultimately causing the motor to work harder to maintain the required flow rate. This extra load translates to higher power consumption by the motor.

In contrast, a decrease in the viscosity or specific gravity of the fluid generally makes it easier for the pump to move the fluid, thereby reducing the power required. A suction head typically helps the pump by providing favorable conditions for fluid entry, which also reduces energy consumption. Similarly, reducing discharge head would lower the pumping requirement, allowing for less energy use. By understanding these principles, it becomes clear how an over-tightened packing gland leads to increased energy demand on the motor.