To what vacuum level must an appliance or component with over 200 pounds of R410A be evacuated before a major repair?

The correct answer is that an appliance or component with over 200 pounds of R410A must be evacuated to a level of 10 inches of mercury (Hg) before a major repair. This requirement ensures that any refrigerant remaining in the system is removed effectively, reducing the potential for contamination and ensuring proper operation when the system is recharged.

In the case of R410A, which is a common refrigerant in HVAC systems, maintaining the appropriate vacuum level is crucial to avoid introducing moisture or other contaminants, which can severely affect system performance and lead to equipment failure. Additionally, reaching a vacuum level of 10 inches of Hg helps to ensure the majority of the refrigerant is removed, allowing for proper maintenance and repair procedures to be conducted safely.

This level is aligned with industry best practices to ensure safe handling and compliance with regulations regarding refrigerant management. When evacuating systems, it's vital to monitor the vacuum gauge to confirm that the system has been adequately evacuated to the specified levels necessary for major repairs.