What action should be taken to minimize refrigerant loss from the purge unit on an R-123 chiller?

To minimize refrigerant loss from the purge unit on an R-123 chiller, performing a leak test and repairing any identified leaks is crucial. Leaks contribute significantly to refrigerant loss, leading to reduced system efficiency and increased environmental impact. By conducting a thorough leak test, technicians can locate any leaks present within the chiller system or connections that may allow refrigerant to escape. Repairs to these leaks can significantly reduce the amount of refrigerant that is purged from the system, thus maintaining better refrigerant levels and ensuring the system operates effectively.

While increasing pressure in the system, replacing the purge unit, or adjusting temperature settings may have effects on system operation or efficiency, they do not directly address the core issue of refrigerant loss caused by leaks. The most effective and responsible action for minimizing refrigerant loss is to ensure that the integrity of the system is maintained through testing and repair.