superheat too high, but pressures look normal...
I checked a 10 ton pkg unit with 2 independent compressor, 2 stage, 2 circuits. One compressor was cooling just fine but not the other one. Unit is an international comfort PGS120H250.Bad compressor was like this:
Low side press: 35psi
High side : something around 190-200psi
Suction tube temperature: 95ºf
Indoor air temp:77ºf
Outside air temp:88ºf
So i recovered, vacc, check for leak... leak schrader valve, replace it and got rid of the leak. Then unit need 3.6lb of refrigerant, charged it and pressures were like this:
Low side press: 79psi
High side press: 300psi
Suction tube temp: 89ºf
indoor temp: 75º-77ºf
outside temp: 90º
Cause the superheat was high i tough the evap was starving cause a restriction, so i replaced the liquid line filter, blow the lines w/nitrogene (lots of dust like oxidation came out) vacc, and charged it again and is doing almost the same thing, pressures that seem to be ok but not cooling and suction temp to high.
Im thinking to replace the header tube for the evaporator, cause it does not has txv or piston, is like a lot of work pulling the evap out welding and all that crap. My question is if it is really the header tube that is resticted or IT COULD BE SOMETHING ELSE??? I was wandering if it could be the internal compressor valves... thanks for the help...