Florida Wastewater Practice Test

If bearings on a pump are excessively hot, what might be the likely cause?

1. Under lubrication

2. Incorrect pump size

3. Over lubrication

4. Insufficient voltage

The correct answer is: Over lubrication

When bearings on a pump are excessively hot, one primary cause can be over lubrication. This situation occurs because excessive lubricant can lead to increased friction and heat generation. The lubricant may not be able to properly circulate within the bearing, which can create a buildup of heat. Additionally, too much lubricant can cause foaming and introduce air into the lubrication system, reducing its effectiveness and leading to further overheating. In contrast, under lubrication would typically result in increased wear and heat due to inadequate friction reduction. Incorrect pump size might lead to operational inefficiencies, but it generally wouldn't directly cause bearings to become excessively hot unless the system is severely overworked. Insufficient voltage could cause other electrical issues, but it does not directly relate to the thermal behavior of the bearings in this context. Understanding these scenarios helps in diagnosing and addressing pump issues effectively.