To what micron level should a system be evacuated during dehydration?

The correct level to evacuate a system during dehydration is 500 microns. Achieving this level is crucial because it helps ensure that all moisture and non-condensable gases are removed from the system. Moisture can lead to corrosion and the formation of acids in refrigeration and air conditioning systems, which can cause serious damage over time.

When a system is evacuated to 500 microns, it indicates that the pressure inside the system has been reduced sufficiently to prevent ice formation or any moisture-related issues, thereby ensuring optimal performance and longevity of the equipment.

Other levels, such as 1000, 250, or 1500 microns, do not provide the same level of assurance that all moisture has been effectively removed. Higher micron levels, such as 1000 or 1500, do not adequately protect against potential problems due to retained moisture, while 250 microns may be suitable for certain applications but is less commonly recognized as the standard for dehydration in Type II scenarios.