When is it against EPA regulations to use system-dependent recovery equipment?

The correct choice highlights that it is against EPA regulations to use system-dependent recovery equipment when the appliance contains over 15 pounds of refrigerant. System-dependent recovery equipment relies on the existing pressure in the refrigerant system to push refrigerant into the recovery vessel. This method is typically not recommended for appliances containing large quantities of refrigerant, as it may not adequately recover all of the refrigerant, potentially leading to environmental harm.

When dealing with larger systems—those containing 15 pounds or more of refrigerant—the use of dedicated recovery devices that are designed to handle these larger charges and ensure complete recovery is mandated. This ensures compliance with regulations aimed at reducing the release of refrigerants into the atmosphere, which can contribute to ozone depletion and global warming.

In contrast, while other options may seem relevant, they do not directly align with the specific requirements set forth by the EPA regarding system-dependent recovery equipment. The regulation emphasizes the weight of refrigerant as a critical factor in determining the appropriate recovery method.