Final answer:
When reservoir air pressure reaches its maximum, the compressor turns off to prevent over-pressurization and turns back on when pressure drops, maintaining efficient operation.
Step-by-step explanation:
When the air pressure in the reservoir is at its maximum, the compressor is typically off or in a non-active state. Compressors are equipped with pressure switches that monitor the pressure level within the air tank. Once the pressure reaches a certain high point, known as the cut-out pressure, the compressor automatically shuts off to prevent over-pressurization. Conversely, when the air pressure drops to a predefined low point, or cut-in pressure, the compressor turns back on to refill the tank. This pressure regulation is crucial for safe and efficient operation.