A prime chiller refers to the initial operation or startup process of a chiller system where it is prepared to function efficiently. During priming, the system ensures that all components such as pumps, pipelines, and the chiller unit are properly filled with water or refrigerant, and any trapped air is removed. This step is essential to maintain smooth circulation, prevent damage to equipment, and achieve optimal cooling performance. Proper priming helps in stabilizing pressure, improving heat transfer efficiency, and ensuring that the chiller operates safely and reliably from the beginning of its cycle.