When testing the tension of the compressor's drive belts, what indicates a need for belt adjustment?

When assessing the tension of the compressor's drive belts, a movement of 1 inch indicates a need for belt adjustment because it suggests that the belt is too loose. A belt that moves excessively can slip during operation, leading to inefficiency in power transfer and potential damage to both the belt and the drive components. Proper tension is crucial for maintaining the performance and longevity of the compressor system.

In the context of the other choices, while visible damage or signs of fraying are certainly causes for concern and warrant attention, they are not direct indicators of tension issues. The movement of half an inch could also be within acceptable limits and typically does not necessitate immediate adjustment. The key point is that the 1 inch of movement is a clear signal that attention is needed to ensure the belt is functioning properly and the compressor operates efficiently.