Massachusetts Wastewater Practice Exam

Which would be the cause for a pump to draw unnecessarily high amperage?

1. Plant worn.

2. Packing too tight.

3. Packing worn.

4. Impeller worn.

The correct answer is: Packing too tight.

A pump drawing unnecessarily high amperage can often be attributed to the condition of its packing. When packing is too tight, it can increase friction within the pump. This resistance causes the motor to work harder to move the fluid, leading to higher electrical current draw or amperage. Proper packing is essential for creating a seal without causing excessive wear or friction. If the packing is too tight, it negates the efficiency of the pump and increases the energy consumption, resulting in the motor drawing more current than necessary. While plant wear, packing wear, and impeller wear can also lead to inefficiencies in a pump system, they do not typically manifest in the same immediate way that tight packing does with respect to increased amperage. For example, worn packing may allow fluid to leak, potentially reducing the workload on the pump and lowering the amperage, while a worn impeller may reduce the pump's ability to move fluid effectively but won't necessarily lead to an increase in required current draw.