However, because split systems require part of the installation to be field-designed, it is important to remember the line set selection/installation can create start-up and installation issues if not considered carefully. A low pressure fault is the most common symptom of a potential line set problem. The three main causes of a low pressure fault are liquid migration, low oil return, and low initial charge. Each one of these potential issues are being addressed through changes in controls, components (crankcase heaters and bi-flow liquid line solenoids), and field piping.
TB09.001 LP Lockout Splits - 684 kB