How deep of a vacuum should be pulled during the first part of a triple evacuation?

During the first part of a triple evacuation, the goal is to ensure that moisture and other non-condensable gases are sufficiently removed from the system. Pulling a vacuum to a depth of 1500 microns is generally considered to be an effective level for initial evacuation, as it helps to minimize the presence of moisture along with any other contaminants.

In HVAC/R systems, moisture can lead to serious issues like acid formation, which damages components and shortens the system's lifespan. Achieving a vacuum level of 1500 microns can help to significantly reduce the volume of moisture present in the system. A deeper vacuum is desirable but can also be more time-consuming and may not be necessary for the initial evacuation step.

While the other options suggest different levels of vacuum, 1500 microns strikes a balance between effective moisture removal and operational practicality, making it the standard recommendation for the first phase of a triple evacuation. It enables technicians to prepare the system adequately for the next stages of the evacuation process, ensuring a cleaner and more reliable HVAC/R system operation.