I did a big house on CT shoreline roughly 9000 sq ft. I used 6 first co hbxb variable sp ah's with Ruud 14AJM outdoors. There was a group of four units that did the main portion of the home. Two of the units were for the room over garage and pool house. The other four were located 40 ft off the house in a dedicated area. Each of the four linesets ran through individual 4in PVC ran by excavator. I had 300lbs of nitro hold for a wk. Went back evacuated the nitro vac down and opened. Power was all set with sub panel at condensers so was able to start up. 3 units were running great but had a short in the low voltage on 1 unit so I opened the valves and left off until electrician fixed the short. Two weeks later I go back to start and when put gauges on It wouldn't equalize. I can't remember what the readings were but they scared the crap out of me. Somehow the oil migrated to the evaporator and plugged up the TXV. Thank god the first co is compression fitting and not brazed in. I disconnected the expansion valve and blasted nitrogen through and blew oil all over the knee wall of the attic. It was one of the worst problems I had on a new install and was worried about how much oil was lost from compressor. a year later system is running fine but what a day!!