What is the reason refrigerant cannot be recovered without isolating a parallel compressor system?

In a parallel compressor system, multiple compressors work together to cool a system more effectively. Each compressor can be influenced by the others, particularly through shared refrigerant pathways. The crucial reason that refrigerant cannot be recovered without isolating the system is due to an open equalization connection.

When there is an equalization line that connects the compressors, recovering refrigerant from one section can inadvertently lead to the movement of refrigerant from other sections as the pressures equalize. If the system is not isolated, the pressures in the various parts of the system will adjust and balance out, preventing proper recovery. This can lead to incomplete refrigerant extraction and possibly over-pressurization of certain areas in the system, which can cause safety hazards or equipment damage.

Properly isolating the compressors ensures that each section is treated independently during the recovery process, allowing for effective and safe refrigerant removal. This procedure is vital to comply with federal regulations and to prevent environmental harm caused by any potential refrigerant leaks.