service fitter 79
04-20-2010, 10:39 PM
Journeyman service Tech. Need help. First time posting. Working on a freeze Drier in a production lab. I'm a RTU/Chiller tech. Basically have a two stage recip. With R502 Going into 4 solinoid valves: Cond. de-superheat Shelf and Neg. shelf. I have ref. system working properly. Condenser shelf cools to -50c and is served directly with txv. But Negitive shelf / product side will not cool to -50c it is at a positive 40-45c. The refrigeration goes threw a heat exchanger where a silicone heat transfer fluid serves the neg. shelf. Had low psid across fluid pump so I drained silicone fluid to check pump. Impeller and pump appear to be in good working order. If anyone has worked on a virtis subliminator and has any ideas please let me know. Only thing left on my mind is was the pump air bound, but it is a sealed system?