On an A/C service procedure, when both refrigerant valves on the service machine are opened, which function is performed?

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Multiple Choice

On an A/C service procedure, when both refrigerant valves on the service machine are opened, which function is performed?

When both refrigerant valves on the service machine are opened, the system is connected on both the high and low sides, allowing the machine to perform the full service sequence. This setup enables evacuating the system with the vacuum pump, pulling a deep vacuum to remove air and moisture, and then charging or weighing in refrigerant to the correct level. In this mode, the machine can circulate refrigerant, evacuate, and replenish the system as needed, which is precisely what the service function encompasses. Other modes—diagnostic, calibration, or safety testing—do not require this two-side connection and are focused on checks, adjustments, or interlocks rather than the actual flow of refrigerant for evacuating and charging.

When both refrigerant valves on the service machine are opened, the system is connected on both the high and low sides, allowing the machine to perform the full service sequence. This setup enables evacuating the system with the vacuum pump, pulling a deep vacuum to remove air and moisture, and then charging or weighing in refrigerant to the correct level. In this mode, the machine can circulate refrigerant, evacuate, and replenish the system as needed, which is precisely what the service function encompasses. Other modes—diagnostic, calibration, or safety testing—do not require this two-side connection and are focused on checks, adjustments, or interlocks rather than the actual flow of refrigerant for evacuating and charging.

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