I had a call this past week on a 50 ton York split system, all I was suppose to be doing was confirming a bad compressor. The compressor was bad, (mechanical failure). The customer informed me that this was the eighth compressor in four years that has gone bad on the machine (mechanical and motor failures). The machine has four Danfoss scroll compressors, a tandum on each circuit. I talked to a co-worker about this and he seems to think that Danfoss makes a shotty compressor and the only way to fix the problem is go back with all copeland compressors. The unit runs at least one compressor 24/7. The unit serves a clean room where temp. and humidity are critical. They keep the room temp at 65 degrees. Keeping the room this cold caught my eye. The unit has oil traps installed and all of the piping is correct with circuit #1 having hot gas bypass installed. Anyway I replace the old compressor and got the machine running. When it started getting the room down below 70 degrees it started bypassing the hot gas. Only circuit #1 has this, but both circuits are losing compressors. Does anyone have any input on this or an opinion on danfoss scroll compressor. Also does anyone know if cleanrooms are normally keep this cold? Any advice would be appreciated.