Which of the following is not a possible cause of a centrifugal pump overloading the driver?

In a centrifugal pump, the driver (such as an electric motor) can become overloaded due to several factors related to the pump's operation and the characteristics of the fluid being pumped.

When the speed of the pump is too low, it typically does not contribute to overloading the driver; rather, it often results in reduced flow and pressure output. This reduction can lead to less power consumption because the driver operates according to the pump's performance curve, which illustrates how power changes with varying flow rates and heads. Thus, a lower speed generally means the pump is working within a more manageable range, preventing the driver from becoming overloaded.

On the other hand, using the wrong liquid with a viscosity that is too high increases the resistance against the pump's impeller, leading to higher power draw than what the driver can handle. Similarly, packing that is too tight creates excessive friction, which also contributes to an overload scenario by requiring more power to overcome the added resistance. Finally, if the discharge head is too low, it may result in the pump operating beyond its designed capacity, thereby demanding more energy from the driver, which can lead to overload as well.

Understanding these dynamics is key in ensuring that a centrifugal pump operates efficiently without overloading the driver.