What problem is likely to cause bearing failure in a standby condensate return pump after a long period of inactivity?

The correct answer is false brinelling. This phenomenon occurs when bearings are subjected to static loads for an extended period, which can happen when equipment has been inactive, such as a standby condensate return pump. In such situations, small vibrations or movements can cause localized deformation on the surface of the bearings due to the weight they are supporting. This deformation can lead to indentations and wear on the raceways, ultimately resulting in premature failure.

False brinelling is especially relevant in applications where the pump may remain idle, as it can go unnoticed until the equipment is started again. Ensuring that the bearings are adequately protected, either by using specialized lubricants or periodic operation, can help mitigate this issue when a pump is not in regular use.