Working on an 7-10 year old Trane Voyager RTU thats about 5 tons i'm guessing, and experiencing low suction pressure. A different service tech where i work came to the conclusion that this unit had plugged orifices and I was sent to install a new orifice kit. When I got there, I did observe the orifices frosted up.
Here are some numbers before I performed the work...
ODA: 84 degrees
Head press: 230-240#
Suction: 38 - 42#
Superheat: 50 degrees
Subcooling: 22 degrees
RAT: 75 degrees, SAT: 60 degrees (15 TD)
LL temp: 88 degrees, Suction line temp: 68 degrees
No temp drop accross the drier and no temp drop up to the liquid header.
Changed out the orifices with the new orifice kit and weighed in charge...long story short... I'm getting the same numbers as above.
This compressor had been changed out about year ago because it was shorted to ground...and why was it shorted?? Dont know, didn't get that info.
I find this to be incredibly odd and not sure what to do next.
Has anyone else experienced anything like this? Oil logged in evep? This is screaming a restriction in the evap, could it be? Possibly an oversized replacement compressor?